Po-TAY-to, po-TAH-to: Let’s call the whole yam thing off!

As most folks in the US prepare for a Thanksgiving meal, or at least eat more Thanksgiving-inspired fall meals, potatoes and sweet potatoes often play a major supporting role in these most delicious victuals.  Whether mashed, smashed, baked, candied, or turned into casseroles or pies, these starchy vegetables are stockpiled in grocery stores and markets in the fall for shoppers to turn into those tasty treats. 

But sometimes there is confusion lurking in those grocery aisles and even in the minds of unwary shoppers….enter the “yam”.  Wander down the canned vegetable aisle and you’ll see canned yams.  Are they the same thing as sweet potatoes?  And are they related to the standard potato that you usually mash, bake, or fry?  I yam going to set the set the record straight. 

First things first, sweet potatoes and yams are two totally different species so they are not the same thing.  They’re even in different plant families so they aren’t even closely related.  And neither of them are related to the regular old potato.  So those “canned yams” at the grocery store are mis-named.  They are sweet potatoes.  Yams are rarely consumed or sold in the US, except usually though markets that sell specifically African/Caribbean foods. 

A sweet potato in bloom….look familiar?

Sweet potatoes are soft when cooked, thin/soft skinned, usually pretty sweet, and usually orange.  Though there are some white-fleshed, less sweet varieties available.  Native to tropical regions of the Americas sweet potatoes, or Ipomoea batatas, are members of the Convolvulaceae, or bindweed, family and are closely related to morning glories many of which are in the same genus Ipomoea.  These sweet veggies are part of the root structure, so they are modified storage roots that store starches and sugars produced by the plant. 

Yams, on the other hand, are white with a hard skin like tree bark, and are usually pretty dry when cooked.  There are three main species of yams in the Dioscorea genus, which has its own family Discoreacea.  Also tropical in nature, three different species were domesticated independently in Africa (D. rotundata), Asia (D. alata), and the Americas (D. trifida).   Yams are monocots, meaning they are more closely related to lilies and onions than they are to sweet potatoes.  Also, unlike sweet potatoes, the edible portion of a yam is a tuber, which is structure arising from modified stem tissue. 

Piles of yams…that look nothing like sweet potatoes

And just to round out the tater trifecta – the humble potato.  Sometimes called a white potato or an Irish potato (which are both bad descriptors for them because they come in many different colors, and while they are a staple in Ireland they originate from the Americas), these versatile spuds, Solaunum tuberosum, are members of the Solanaceae family and are closely related to tomatoes, Solanum lycopersicum.  Their morphology has similarities to those of the yam, though, as they are tubers arising from the stem vs being a root like sweet potatoes. 

So where does all the confusion come from? 

There are various theories on how yams and sweet potatoes got caught up in this mash-up, and I don’t pretend to be an expert here.  But the most common theory that I’ve seen is that enslaved African people held in the US south called the local sweet potatoes by the names they used for yams, as the sweet potatoes reminded them of the yam that was part of the staple diet in many African countries.  The word yam is derived from nyam, nyami, or nyambi, meaning “to taste” or “to eat” in certain African language dialects.  Adding to the story, apparently Louisiana sweet potato growers in the 1930s used “yams” as a marketing name for a new orange-fleshed sweet potato cultivar and the name stuck. 

One thing I find interesting is that yam was used to describe orange sweet potatoes when the white fleshed ones (which are less common now) would probably more resemble an actual yam, both in appearance and flavor.  In fact, in my travels in Rwanda I ate many white fleshed sweet potatoes, as they are now a major staple crop in many African countries.  It is also interesting to note that the refugee farmers in our urban farm programs prefer to grow the starchier, less sweet varieties of sweet potatoes, which often complicates things as they can be hard (and expensive) to find. 

Whether you cook sweet potatoes or “white” potatoes for your Thanksgiving feast, now you’ll know a little bit about how each of those crops are different…and you’ll at least know that sweet potatoes aren’t yams. 

Big Blog on the Block

There’s a new1 blog on the social media block—The Big Blog of Gardening (BBoG). Already it’s a heavy hitter in the gardening social media world. The question is: How may foul balls are hit?

My wife came to me recently saying “Hey! Did you know that your friend Linda Chalker-Scott changed her institution?”
“What?” I said.
“Yeah, she moved to University of Washington. It says right here on this MSNBC article.”
“It’s from the Big Blog of Gardening? What’s that?”
Turns out that the BBoG is hooked into national media and gets consistent play on the home pages of those who go to MSNBC. This is because the BBoG is “now part of the Microsoft Start Program” that places content on the MSN homepage whenever a user logs in.

The originator of the BBoG is not a scientist and in the “About” section of his web page states that he started gardening as a child (like many other of us that had school gardening programs around the country). I also started gardening as a child, volunteered at Descanso Gardens in La Canada, but in my own case I followed up my childhood experiences with a dual major in Botany and Horticulture, an MS in plant pathology, a PhD in plant pathology, and a 30-year career with Cooperative Extension advising and researching in landscape horticulture. These are the typical qualifications for the blog writers at the Garden Professors web pages. Unlike writers for the BBoG, we are the folks who actually conduct research on horticulture and gardening subjects that other people quote and cite.

For us scientists, one of the pitfalls of the BBoG is it’s not a science-based blog. In a blog on pruning, the title proposes to inform how to prune any landscape plant. When you read that article, it just directs you to a link to Amazon.com to purchase a publication of the American Horticultural Society (which is not a science-based organization even though it sounds very much like the American Society for Horticultural Science – the oldest horticultural science society in the US). Rather than cite current research or address the blog title’s topic, the article leads to a product you have to buy to get your information. BBoG posts are full of of links to products available online or to “paid for links” for non-scientific and misleading garden books or other resources.

Broad strokes are used in titles of the blog. For example: “Staking a tree is almost never the right thing to do”. In some ideal world where nurseries grow trees w/o stakes and landscapes don’t require protection from damaging elements this may be true, but this is not the world we live in. Trees grown in nurseries are often staked to facilitate production and shipping. Staking can be used as a protection process on trees that may suffer impact from moving vehicles (these stakes have no attachment to the tree but serve as protective bollards). Titles in some other posts are merely attention getting or serve to promote products – not to reflect accurate horticultural science.

The BBoG often cites Dr. Linda Chalker-Scott, quotes her published work, provides links to her white papers, but doesn’t actually email or otherwise contact the original author. The problem is that often there are peer-reviewed sources by the same author containing this newer information (e.g., WSU Extension publications). BBoG often seems to miss the actual scientific or peer reviewed work but focuses on popular sources such as Fine Gardening or, even worse, Consumer Reports. Consumer Reports is not a legitimate resource for science-based information. (link to Jeff Gilman’s blog post)

Beware the comments at the end of articles on the BBoG as there can be pseudo-scientific information there (using gypsum to create drainage in soils) that goes unrefuted by the article authors. It is important that site administrators approve comments before they are listed, or at least address the misconceptions in a response.

When BBoG stories hit the mainstream media (like MSN) the blog owner does not always mention the original sources of their stories, or the scientists who developed the information: they take credit and reap the rewards of increased eyeballs on their posts and clicks on their advertising links. Wouldn’t it be nice if members of the media could dig a little deeper and find the science-based gardening sites and give them some well-deserved publicity?

Frosts and freezes: As cold as ice…

Here in the Southeast we were surprised last week by a much earlier than usual freeze, putting an end to many gardens full of tender plants, although the cold was not deep enough to kill more cold-hardy species. In many parts of the region the frost came earlier than the 10% probability of frost indicating that early freezing conditions like this will come in fewer than one in ten years. Of course many of you in more northern interior parts of the United States have already seen your first frost this year, but here we never seem to be ready for it. In fact in parts of southwest Georgia last year’s first fall frost did not turn out to be until well into January, which caused a lot of problems for gardeners and farmers who had to deal with pests and diseases that easily overwintered the mild conditions.

Map

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Median date of first 32 F fall frost, from https://www.weather.gov/iwx/fallfrostinfo.

Frost versus freeze

One of the questions I often get this time of year is what is the difference between frost and freeze? The National Weather Service (NWS) puts out both frost and freeze warnings but has different criteria for each. For a frost warning, the predicted temperature may not even get down to 32 F (0 C), but may hover in the mid 30’s. For a freeze warning the predicted temperature is expected to get down to 32 F or below and for a hard or killing freeze it usually gets down to 28 F or lower. Once the area has gotten down to 28 F or lower, the NWS usually stops issuing additional freeze warnings since at that point all but the most cold-hardy plants have completed their growing season and are either dead or dormant.

A close up of a spider web

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Hoar frost on Indian rice grass. Source: NPS Photo by Neal Herbert at Arches National Park via Commons Wikimedia.

How does frost form if the temperature does not get down to freezing?

To understand frost formation and when warnings are issued it helps to know both how frost forms and how temperatures vary near the ground. Frost crystals form on surfaces that get down to freezing and have something on the surface that is conducive to seeding crystal formation. This can happen even when the air temperature is above freezing in conditions of light wind and clear skies that allow surfaces to cool to freezing temperatures by emitting heat radiation out to space at night when there is no incoming solar radiation. Conditions for this can occur with temperatures anywhere in the 30s with a reasonable amount of water vapor in the air and as long as the surface (a metal car body, an asphalt roof, or a blade of grass) can cool to the freezing point. At that point, anywhere on that surface that has an appropriate scratch, particle, or other imperfection can serve as a place for ice crystals to form and start to grow. These are called nucleation sites and allow the initial formation of an ice crystal upon which more ice can grow into delicate but visible frost.

Frost will not form if the humidity is too low because there is not enough moisture to produce visible crystals. Often frost does not damage the plants a lot because most of the frozen water is confined to the surface of the plant and does not affect the interior cell walls, although there may certainly be some damage where the ice forms. Large formations of ice crystals can sometimes form on trees or fences if the conditions are right; this is called hoar frost.

Hoar frost on ”Burgbühl” (also Hexenbühl) near Obernheim (Swabian Jura). Source: Olga Ernst, Commons Wikimedia.

Frost forecasts are also provided with the understanding that the NWS is forecasting temperature values for their thermometer heights of about 2 meters or 6 feet high, since that is how they verify the accuracy of their forecasts. In light winds and clear skies the temperature at the ground level is often colder than the temperature at the thermometer height due to cold air sinking so the ground in your garden may be colder than the forecast would predict. Frost is also more likely to form on elevated surfaces that don’t have contact with the ground, since soil temperature keeps the ground surface warmer in Fall than later in the year due to residual heat from the summer warmth. Blueberry farmers that I work with tell me that you can sometimes see quite a difference in frost damage to their bushes from top to bottom due to the different temperatures that the plant may experience at different heights above the ground. Bridges often have signs that they freeze first for the same reason.

A close up of a flower

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Saucer magnolia with freeze damage. Source: Famartin, Commons Wikimedia.

Freeze damage to garden plants

The NWS issues freeze forecasts when the temperature is expected to get down to or below 32 F. The damage that the freeze does to plants depends on how long the temperature drops below freezing and how susceptible the plant is to cold temperatures. If the temperature barely gets down to 32 F for a short period damage is likely to be minimal since the water inside the plant cells did not have sufficient time to freeze. But if it lasts longer the water in the cells freezes and, as you undoubtedly know, ice expands and breaks the cell walls causing irreversible damage to plant leaves and stems that leads to their death. John Porter provided a useful table of how different garden vegetables respond to cold temperatures in his 2020 blog on spring frosts, which underlines why some vegetables like spinach and cauliflower do better as late-season vegetables than tomatoes and melons.

The discerning reader who looks at John’s article will also note some differences between the first frost map he published in his blog and the map above, because they cover different time periods. John used the map for 1980-81 to 2009-2010, since that was the current one at the time of his post. The map here uses the 1990-91 to 2019-2020 period since the normal temperatures have been updated since John’s blog was published. Average frost dates change over time as you can see especially in some areas like eastern Oregon and northern New York State and generally, as the earth gets warmer, the first frost of fall is occurring later in the year than it did in the past (although there are a few exceptions such as parts of northern Georgia).

Frosted Kale. Source: Tracy from North Brookfield, Massachusetts, USA, Commons Wikimedia

With winter on the way, we are sure to see many more examples of frosts and freezes in the coming weeks for almost everyone other than those who live in tropical areas. For those of us who enjoy chilly weather, the magic of frosts and freezes is something we look forward to as it paints our dying gardens in icy white.

Understanding how weird weather affects our plants

Nutrient deficiency? Or something else?

I’d intended to write the column earlier in the year, but it’s as relevant now as it was in the spring. This post will familiarize you with how unseasonable weather can affect your plants. Though I’ll be focusing on my own location in Tacoma, the phenomena are global. You just have to pay attention to what happened last week, last month, last year in your own location.

Our two potted Japanese maples

Our spring started out wet and cool, which is nothing new. But it was REALLY wet and REALLY cool compared to normal. This meant that our trees and shrubs had plenty of water to fill their expanding leaves and blossoms – but the lower than normal temperatures affected leaf growth. These dwarf Japanese maples had lots of leaves, but they were tiny! And they stayed that way, because once the leaves begin to lay down cuticle, they don’t expand any longer, even when it gets warmer. These maples put on a second flush of growth in the summer. Look at the difference in leaf size, determined solely by ambient temperature.

We had an abundance of flowers on our fruit trees – so dense that I put off pruning some of our heritage apple trees so we could get an even bigger crop (our black Angus love apples). But summer rolled around and…virtually no apples on ANY of the trees. What happened?

Normally, our apple blossoms are opening when there is lots of insect activity

Well, that cool spring ensured that most of our pollinators were late to emerge from overwintering. I had wondered about them in the spring, as I could only see a few pollinating flies and no bees. But sure enough, we had almost zero pollination. No apples this year. Next year if the weather is similar I’m going to try using my battery-powered leaf blower to pollinate these trees. I’ll take pictures.

This chart only goes through August 28. We had no rain until October 20th.

Fast forward to summer – for us, a record-breaking drought (again). Our temperatures weren’t as high as last year, but we still had very hot weather and no rain. For our landscape it’s not a problem, as we have well water for irrigation. But those gardeners who have little or no supplemental irrigation may very well find that their woody plants and perennials don’t perform very well next year: perhaps fewer flowers or branch dieback will appear. This is due to root dieback that happened all summer in unirrigated conditions. The damage is only seen in the following spring, when there aren’t enough roots to supply water to emerging buds.

Crown dieback from water-stressed roots.

Being able to predict the impact of specific weather events on your landscape plants is key to avoiding misdiagnosis and subsequent misuse pesticides or fertilizer in a futile attempt to rescue them.

Oh, and if you are wondering about the photo at the top, you’ll have to look at a post from 2009 to see what’s going on.

Tulips for the desert?

Spring bulb planting time is on across North America!  Many types of bulbs do well in desert and xeric gardens: hyacinths, ranunculus, iris, narcissus, crocus, alliums can all be happy. One bulb that’s often left off the list are tulips. Why is that?

The tall flashy hybrid or Darwinian tulips that fill the catalog photos are usually considered an annual in most desert gardens. They require more chilling than the our desert winters can usually provide and can be a little fussy about soil and water.
But tulips can be very happy in xeriscapes. In fact they can get so happy they’ll set seed and naturalize in the right conditions. And which tulips are those you ask? (Yes you did, I heard you.)
They’re species tulips and are non-hybridized. They’re more of “wild” type of plant. What’s so special about them?
They’re tough, amazingly tough.

Tulips are originally from mountainous areas of the Mediterranean, Middle East and Asia. Some are also native to Southern Europe, North Africa, and several Mediterranean islands. They’re frequently found clinging to barren mountain ledges, rocky areas exposed to wind and cold, and drought ridden slopes.

Map by Tulips in the Wild
For an interactive format with species information go here:
https://www.tulipsinthewild.com/map_table/tulip_origin_map.html

Species tulips are shorter and smaller than hybrids but what they lack in stature they more than make up for in resilience and showy display. They’re an early bloomer in the desert southwest which is wonderful for the pollinators that are often active on warm winter and early spring days.

Their foliage is usually more varied than hybrids; some have broad, curled edged leaves, some are tall and narrow. The color varies too, from a bluish tint to shades of green. Some varieties even have multiple blooms per stem.

Many species are attractive whether the blooms are closed or opened. They often have very different coloration inside and out.

Closed…
…and open

Some have contrasting pollen color which adds great visual interest.

These have a deep purple pollen.

Species tulips are usually perennial in warm winter climates. They increase via bulb offsets while many will set seed. They aren’t fussy about soil as long as it’s well drained. But like all plants they do require water during bloom and while the leaves are green but still, not as much as other bulbs. They’re perfect for xeriscaped or low water landscapes since they require less overall water than other bulbs. Plus, they prefer to be dry during their dormant season, which is summer to fall.

These tough little beauties can occasionally be found in garden centers but for the best selection shop online, search for “species tulips.” Do some homework first, and become familiar with the the available varieties.

Plant these tulips from fall to early winter. Provide full sun and good drainage, rocky or lean sandy soils are ideal and most closely approximate their native conditions.

Don’t overplant with species that require a lot of summer water. Mix these bulbs with other plants that prefer hot dry conditions. Tuck them into those corners that get spring – early summer sunshine, spots that don’t get much summer water, or put in containers that you can enjoy and then ignore during the summer. Pot them in cactus mix combined with a small amount of regular potting soil and top with an organic mulch. Remember, drainage is a must and overly rich or high organic matter conditions aren’t to their liking.

If you live in a dry or desert region and have never tried species tulips, why not give them chance. You might just discover a new favorite.

Predicting hurricane tracks and what they leave behind

In my last blog post in late August, the Atlantic tropical season was just beginning to wake from a long nap, with several areas of interest appearing on the National Hurricane Center’s (NHC) map. Since that time, the season has become incredibly active, with Hurricanes Fiona and Ian causing tremendous damage in North America. Other parts of the world have also seen damaging storms, including Hurricane Kay in the Eastern Pacific, post-typhoon Merbok in Alaska, and Typhoons Hinnamnor in South Korea, Nanmadol in Japan, and Noru in the Philippines. So, with apologies to those who live far from hurricane parts of the world, I want to talk one more time about tropical systems.

Heavy rain. Source: Faldrian, Commons Wikimedia

Where do we stand with the tropical season now?

As I am writing this on Thursday morning, September 29, I hear the sound of Ian’s wind in the tulip poplar trees outside my house in Athens, GA. Ian is still in central Florida, just about to come off the coast into the Atlantic Ocean, so that gives you an idea of how far the influence of a tropical storm can spread, especially with a strong high-pressure center to our north that is increasing the pressure gradient driving the winds. Ian made landfall yesterday afternoon near Fort Myers, Florida, as an almost-category 5 storm, with winds of 150 mph (some reports say 155 mph). The videos I saw yesterday showed the power of the storm, with tremendous wind gusts and a storm surge that surpassed 10 feet in some places. I know the damage is horrific, and some of those areas will never recover completely from the storm, as buildings have been washed away and even shorelines may have changed due to the force of the wind and water. Since Ian is expected to curve back toward the East Coast on Friday and may strengthen again, its effects are not over yet. Fortunately, a weaker storm has lower impacts, but folks along the Georgia and South Carolina coasts will be feeling those impacts in the next few days before Ian moves out of the area and dissipates.

Hurricane Ian, September 27, 2002.

Hurricane Fiona lashed Puerto Rico and the Dominican Republic with rain of up to two feet in some places around September 18-19 before moving rapidly to the north and slamming into Nova Scotia as a post-tropical cyclone on September 24. It caused tremendous damage in both places from storm surge, wind, and rains. The floods in Puerto Rico destroyed a lot of local farms and gardens in the southern half of the islands where the rain was heaviest and in doing so, eliminated an important source of locally produced food as well as disabling a fragile power grid that had not yet recovered from Hurricane Maria in 2017. The storms in other parts of the world have had similarly bad effects on the lands over which they moved, with loss of trees and buildings and high storm surges wiping out coastal infrastructure. Not all hurricane impacts are bad, however, since the rain from Hurricane Kay in southern California helped reduce drought conditions there in a time when not much rain usually falls in that part of the world.

Predicting the tracks of hurricanes

One of the questions that have arisen with Hurricane Ian has been the prediction of where the hurricane would go. Predicting the track of a hurricane is an art that includes the use of multiple computer models that simulate conditions over the life of the storm. That includes sea surface temperature, vertical atmospheric structure, and the surrounding wind field which will push the storm around. On the news you will often see maps that show all the individual model results on one map, which ends up looking like a mass of spaghetti noodles, hence the term “spaghetti models”.

Ensemble of Hurricane Ian forecasts from the GEFS model issued on September 26, 2022. Source: WeatherNerds.org

Forecasters look at all the individual model tracks together to see how consistent they are with each other and where the differences lie. Then the human forecasters use their knowledge of how well those models behave under different weather conditions to create a “forecast cone” that shows the region where the center of the storm is likely to go.

No one model is right all the time because they weigh different weather factors differently. In the case of Ian, the models run by European weather services did better, but that is not always the case. Generally, they say that 2/3rd of the time, the central low pressure will stay within the predicted cone, although the storm itself is usually much larger than the cone and hazards like high wind, heavy rain, tornadoes, and storm surge can and do occur far outside the cone. If there is a lot of spread in the models, then the forecast cone is wider, indicating that they are less certain about where the storm will go.

The models are run every six hours or so, and each time the cone is updated to include model results that include new weather data observed since the last forecast was issued. As this happens, people that are in or near the cone must respond to the forecast by deciding whether to evacuate or stay in place and where to go if they do leave, since they don’t want to evacuate to a location that could be hit by the storm if the cone shifts. When the forecast is especially tricky, as it was with Ian, the movement of the cone over time can become overwhelming to people who just want to find a place they will be safe. The forecasts of where the storm is likely to travel are improving over time, but the tracks will never be 100% accurate because the atmosphere is a complicated place that we can’t simulate perfectly using even the best computers, so confusion is likely to continue to occur in future storms.

Downed trees and powerlines in Bartow, FL, following Hurricane Ian. Source: State Farm, Commons Wikimedia.

Dealing with flooded gardens

Since this is a blog about gardening, I want to end up mentioning what impacts these storms have on gardens. Coastal areas where there is a storm surge will see inches to feet of seawater flow over their land. The water contains salt but can also contain toxic chemicals from boats and tanks that are damaged by floating debris or strong waves. The salt and chemicals can kill garden plants but also may get deposited in the soil as the water sinks in, leaving toxic residue behind. The physical motion of the water on and off the land can also scour the topsoil and change the soil structure or deposit sand on top. Saturated soils can drown the plants by keeping oxygen from reaching the roots of plants. And of course, the howling winds can snap the plants, bushes, and trees above the ground, leading to damage that can be taken advantage of by pests and diseases. In areas where there is heavy rain and freshwater flooding, salt is not usually a problem, but all the other problems with too much water can occur there, too. For those who live where storm damage is heaviest, helping their gardens to recover will be a long process even if their houses survive the storm.

Hurricane Ian clouds at sunset. Source: Jason Mallard.

The Atlantic tropical season is not over yet for us in the Southeast, but I know that in other parts of the United States and the world, the seasons march on, so in the next months I will move on to talk about fall frosts and the upcoming winter. Thanks for bearing with me as I explore tropical storm systems. Please keep all of those affected by our storms this year in your thoughts and prayers as they work to recover from damage and disaster.

Irrigation bags: the good (rarely), the bad (frequently) and the ugly (all of them)

Irrigation bags, often called “tree gators,” are durable plastic bags used for irrigating newly planted trees. These projects have been discussed here and here and I still don’t like them as they don’t consistently benefit trees and often create conditions conducive to pests and disease. Plus, as the blog title suggests, their aesthetic attributes are nonexistent.

Surprisingly, camoflauge green doesn’t actually camoflauge anything.

Newly installed trees and shrubs generally need to have supplemental water, period. It doesn’t matter if they are “drought tolerant” species – any plant needs sufficient water to establish roots. And where automated irrigation systems aren’t possible, there are many products that promise to deliver water to the establishing root system. Unfortunately, they often deliver other things as well, including pests, disease, and early death.

To be fair, many time these trees die because they were poorly planted: we know that improperly amended soils, structurally compromised root systems, inadequate root preparation, and/or poor installation are the leading causes of young tree failure. But anything that covers the trunks of young trees and reduces air flow and light exposure will, over time, create a dark, moist, and reduced oxygen environment that’s damaging to the bark of young trees. Wet, damaged bark allows opportunistic pests and pathogens to invade.

Until a few weeks ago, I had not seen any irrigation bags that I actually thought might work. These bags are installed on stakes away from the tree trunks, and they deliver water to the area where tree roots need to grow, enhancing root establishment. It took a trip to Malmö, Sweden to see this innovative approach and my immediate reaction was “why hasn’t anyone thought of this before?”

There are many types of irrigation bags, from sleeves to donuts, but none of them are as good for tree or soil health as a thick layer of arborist wood chips. When wood chips can’t be used for some reason, irrigation bags set well away from the tree and actually kept full of water might be a good solution.

Arborist wood chips provide a highly absorbant matrix that releases water slowly into the root zone.

What the words on the seed packet or food label mean…

This article was originally published (surprisingly?) by the Mother Earth News Blog.

What do the words on your food (or garden supplies) labels mean? Do you know the difference between organic, natural, and sustainable? Are there rules about who can use which labels? When you are shopping at the farmers market or grocery store, or when you’re buying seeds or plants at the garden center, it is important to know what the words used to describe the product mean. It is also important to understand that some words have different meanings to different people and sometimes are used more for marketing (and sometimes misleading customers) than conveying actual meaning. Let’s take a look at some of the words that have an “official” definition, some where the meaning can be interpreted differently, and some that can be misleading or misinterpreted.

“Official” words for foods and plants

There are a handful of words that you’ll find at the grocery store, farmers market, or garden center that have an official definition because they are either part of a law or code or are part of an official certification process.

USDA Organic | USDA

For example, in the US for a product to bear the term “certified organic” or “organic“, it must be produced in accordance with the National Organic Program organic certification process outlined in federal policy/law and administered by the USDA. While there are many minute details for organic production, the “big picture” definition is that only organic/naturally occurring soil amendments and pesticides can be used – typically from a biological or elemental source. It is important to note that organic does not mean pesticide free. Repeat: ORGANIC DOES NOT MEAN PESTICIDE FREE

The organic certification process can be costly and time consuming, and some producers feel that restrictions do not go far enough, so alternative certifications have been developed such as Certified Naturally Grown and Regenerative Organic Certified. These certifications are not administered by the USDA, but rather by individual organizations that have developed them.

Another term that has emerged is “biodynamic,” which marries some organic principles with the requirement that the farm be a “closed system”, meaning that outside inputs like fertility are not used. Biodynamic production also requires the use of “preparations” that would be described as mystical or homeopathic and must be practices in accordance with “energies” such as the phase of the moon. In order to be labeled “biodynamic” a product must be certified by Demeter USA. Our very own LCS has addresses the “pseudoscience” of biodynamic growing in a previous paper. As a science-based group, we consider biodynamic to mainly be WOO.

A number of other certifications exist, such as Certified Animal Welfare Approved and Salmon Safe that guarantee things like best practices in livestock welfare and proper wild fishing practices.

“Unofficial” words for growing and marketing

While “official” words have certifications that standardize their meaning across industries, other words we use for production and marketing don’t have official meanings and are often up for interpretation. In instances where a relationship exists between a consumer and producer, say a customer buying directly from a farmer at the farmers market, a conversation can take place to share the meaning of what the words mean. In situations like a product at the grocery store, words are often left to the interpretation of the customer.

For example, while the term “organic” or “certified organic” requires official certification, using the term “organically grown” does not. Many small farmers will use this term to reflect their use of organic practices, but their understanding of practices may deviate from the “official” definition. The term natural or naturally grown may also be used to describe produce or products at the grocery store but no officially sanctioned definition exists. When customers and growers/producers can discuss what the terms mean, an understanding can be developed. However, when such a relationship doesn’t exist, it is hard to know what the terms mean. For example, an ad might say that a product is “natural, so you know that it’s good” to which I might joke that poison ivy and rattlesnake venom are both natural, but that doesn’t mean it is good for you.

The term “local” also doesn’t have a specific definition and can vary widely depending on the context. At farmers markets, it is up to the organization operating the farmers market to create vendor rules and decide what makes sense for each individual market, according to the national Farmers Market Coalition. For example, the closest meat producer may be farther outside of the city than the closest produce farmer. Markets in urban areas may need to recruit vendors from a bit farther away than those in the suburbs. If you have questions about the rules of your local market or where a vendor is farming – just ask! At a grocery store, local can mean whatever the chain wants to decide. Sometimes this can mean in the same state or other times it is regional. Often food at the grocery store will have a label saying the town or region it came from for you to learn more about each specific item.

Walmart's locally grown produce | In Oct. 2010, Walmart comm… | Flickr
Is it “local”? Depends on who you ask.

The terms sustainable and regenerative might be used to describe production practices or a farmer’s philosophy on production. While there aren’t official definitions, the USDA Sustainable Agriculture Research and Education program defines sustainable agriculture as holistic farming practices that balances environmental stewardship, profitability, and personal/social benefit. Though most use of the term sustainable for marketing focuses on the environmental aspect. Regenerative agriculture is a relatively new philosophy of production practices that focus on environmental stewardship to reverse climate change and/or environmental degradation and social fairness and often involves improving soil health. While the terms sustainable and regenerative might seem interchangeable, there are differences (mainly around economic sustainability and around maintaining current environmental conditions vs. improving them). We’ll see how the “regenerative” term plays out – as many consider it to be a “buzzword” in some ag circles.

Words that can confuse or mislead

While there are words that may seem abundantly clear to the person using them, the information or intent may seem totally different to the audience. These words are often used as buzzwords for marketing or may be used to create a sense of fear that is misunderstood. For these words, alternative words or further explanation might reduce confusion.

One such word that is often used is chemical-free. This is often used to describe produce or food that is produced without pesticides. However, use of chemical-free can be misinterpreted and misunderstood. It may be a facetious response, but as a scientist I often cringe when I hear this word used at the farmers market because that I know that everything is made of chemicals – all rocks, plants, animals, humans, and even air and water – are chemicals. Some say that the use of this term is based in fear of pesticides (even organic ones) or is based in anti-science “chemophobia” rhetoric. Using a more precise term, such as pesticide-free conveys the same message without anti-science connotations and reduces the chance of misinterpretation.

Non-GMO is also another term that was created as a fear-based marketing term that has become pervasive at the grocery store, the seed rack, and the farmers market. While there are concerns AND benefits to genetic engineering technology, use of the term non-GMO is often redundant and confusing to consumers because, as it turns out, there are very few opportunities for gardeners, farmers, or consumers to interact with bioengineered crops. Most bioengineered crops are those that are produced as commodities – field corn, soybeans, sugar beets, cotton, canola, etc. Only a handful of crops are those that you’d find at the farmers market or produce section – sweet corn, summer squash, papaya, and one apple cultivar. But these crops are grown in very small amounts, are not available to small-scale farmers or home gardeners, are sold only in larger quantities, and require a contract for purchase. Most produce items grown in the US do not currently have a genetically engineered counterpart – there are no GMO lettuces, radishes, etc. So labeling a tomato as non-GMO is redundant and has unfortunately caused so much confusion and fear amongst consumers that many specifically demand or seek non-GMO tomatoes, even though all tomatoes are non-GMO. There is a third-party certification process through the Non-GMO Project (they’re the ones you see with the butterfly logo on almost every product, even bottled water and salt), however given the confusion and misinformation around the term, the US government recently created a standard “Bioengineered” labeling requirement for all produce and products that consist of or contain genetically engineered crops or ingredients.

A few more words on words…

While words can inform and confuse, being an educated consumer (or producer) can help reduce confusion and help us understand the food that we eat. While we haven’t covered every word you might encounter on a label here, researching words you see can help build your label vocabulary. Building interest in learning about where your food comes from should be a fun way to connect with what is on your plate and who is in your community. Go out there and enjoy the learning process! You can check out some more words related to agriculture and food here.

This article by John Porter was written as part of a partnership in collaboration with staff at the Farmers Market Coalition (FMC) as part of FMC’s partnership with Mother Earth News Fair.



More about seed packet lingo here.

Bee Lawns: What’s all the buzz about?

A bee lawn is a way to benefit pollinators in our landscapes by providing additional floral resources, and often utilizes a mix of low-growing flowering plants in addition to turf species. Although flower gardens also provide flowering plants for pollinators, bee lawns can be multi-functional in their usability for recreational purposes with the added benefit of providing food for bees.

Habitat loss is one of the major factors implicated in the global declines of native bee species. Providing resources utilized by these critical pollinators can assist in mitigating this. Research through University of Minnesota has found 50 species of bees utilizing the flowers in bee lawns.

The purpose of bee lawns includes providing nutritious sources of nectar and pollen for pollinators, especially in urban environments, where these resources can often be scarce and difficult to find. Additional factors include recreational usability, and reducing inputs, e.g., irrigation, nutrients, weed control, and time spent mowing. Flowering plants suited for bee lawns have a variety of common characteristics including: low-growing and flowering heights, perennial life cycles, the ability to persist with turf species, and tolerance of mowing and foot traffic.

An important consideration is that bee lawns don’t necessarily mean weedy lawns or no-maintenance lawns, but instead require different types of management and serve different functions than traditional turfgrass lawns.

Not all bee lawns are created equal, and some work better than others.

Here are some turfgrass species that can work well for bee lawns:

Cool-season turf

A mix of fine fescues (which includes species such as: creeping red fescue, chewings fescue, hard fescue, and sheep fescue) are some of the best options for bee lawns due to reduced needs for inputs including irrigation, fertilizer, and weed controls, in addition to their compatibility with flowering plants. That being said, fine fescues do not tolerate heavy foot traffic, and may not be a suitable option for turf varieties in areas with heavy recreational use.

Kentucky bluegrass (KBG) is another option for bee lawns, though it requires higher maintenance (including more frequent irrigation and fertilizer inputs). KBG is considered an invasive species in some areas so do your homework.

Warm-season turf

Although there is limited research currently available for warm season turfgrasses and their compatibility with flowering plants specifically for bee lawns, certain species require lower inputs and could be a good option.

Centipede grass is a suitable option for a low-maintenance warm season turf species, and has been utilized in studies evaluating early-spring flowering bulbs as part of a lawn ecosystem for pollinators (see resources for more information).

Bermudagrass can also be used with flowering plants, though it has higher input needs than centipede grass. For more detailed information on warm season turfgrass species suitable to your geographic area and their respective input needs, I would encourage you to reach out to your local and regional extension offices.

Here are examples of flowering plants that can work well with turfgrass species:

Dutch white clover (Trifolium repens)

Dutch white clover (often referred to as white clover or clover) is a common occurrence in many lawns. Although some consider this to be a weed, white clover can provide several benefits including its adaptability to many soil types, the ability to withstand some shade and foot traffic, and the added benefit of being able to fix its own nitrogen. Like its name suggests, white clover produces white (and sometimes pink) flowers, and grows to a height of 4-6 inches. In addition to its hardiness, white clover is also an excellent source of forage for bees due to its long bloom time, and the great quality of nectar (high sugar content) and pollen (high protein content).

Dutch white clover flowers in a lawn (Photo: Whitney Cranshaw, Colorado State University, Bugwood.org)

Creeping thyme (Thymus praecox)

Creeping thyme is related to some of our favorite culinary herbs, and produces fragrant purple/pink flowers. It has a low growth habit (<6 inches) and can tolerate some foot traffic. It performs best in well-drained sandy or loamy soils, and is also considered to be drought tolerant and deer-resistant.

Self-heal (Prunella vulgaris ssp. lanceolata)

Self-heal is native to North America, Europe and Asia, and research from University of Minnesota has shown that 95% of the pollinators that visited the flowers were native bee species. It produces purple flowers and does well in a variety of soil types (with the exception of sandy soils) and in sun or partial shade.

Self-heal flowering with turfgrass (Photo: John D. Byrd, Mississippi State University, Bugwood.org)

Common violet (Viola sororia)

Violets are another flower that some consider to be a weed in home lawns. These spring blooming yellow, purple, and white flowers can be a good source of nectar for pollinators such as butterflies and bees. Violets grow to heights of 4-8 inches, and do well in a variety of soil types in addition to sun and shade.

Purple flowers growing in grass
Violets growing in a lawn (Photo: Sarah Eilers, Montana State University)

Other flowers

Additional low-growing flowers could also be great additions to bee lawns, including early spring flowering bulbs that can persist with turfgrass for multiple years, such as crocus and grape hyacinth (Muscari spp.), which have been observed to attract pollinating insects (especially honey bees).

For more information on the regional suitability of flowering plants to incorporate with turfgrass for bee lawns, contact your local extension offices for more information.

University of Minnesota’s Bee Lab has a lot of excellent information on bee lawns, their establishment, and the diversity of bees that visit them:
https://extension.umn.edu/landscape-design/planting-and-maintaining-bee-lawn#turfgrasses-for-bee-lawns-2939360

https://turf.umn.edu/news/if-you-build-it-who-will-come-evaluating-diversity-bees-flowering-lawns

Additional Resources:

https://www.canr.msu.edu/news/consider-a-flowering-bee-lawn-to-help-pollinators

https://extension.psu.edu/the-buzz-about-bee-lawns

Wisdom, M. M., Richardson, M. D., Karcher, D. E., Steinkraus, D. C., & McDonald, G. V. (2019). Flowering persistence and pollinator attraction of early-spring bulbs in warm-season lawns. HortScience, 54(10), 1853-1859.
https://journals.ashs.org/hortsci/view/journals/hortsci/54/10/article-p1853.xml

Larson, J. L., Kesheimer, A. J., & Potter, D. A. (2014). Pollinator assemblages on dandelions and white clover in urban and suburban lawns. Journal of Insect Conservation, 18(5), 863-873.
https://link.springer.com/article/10.1007/s10841-014-9694-9

The 2022 Tropical Season: It’s Alive!

In my last blog post in early August, I noted how quiet the Atlantic tropical season has been so far this year. In fact, the period from early July through this week has been one of the quietest on record, with no named storms since the short-lived Tropical Storm Colin formed along the South Carolina coast and dissipated less than 24 hours later on July 3 in eastern North Carolina. The last time we had so few named storms was 40 years ago, so while it is not unprecedented, it is certainly unusual. And we are definitely later than the average date for the first hurricane of the year. By comparison, in 1992, a strong El Niño year, Hurricane Andrew (an “A” storm, so the first of the year) had formed and taken its devastating track through southern Florida and Louisiana by this date.

Atlantic 5-day outlook on 8-28-2022

All of that is about to change, and hurricane forecasters are relieved after predicting a season of above-normal activity based on warm ocean temperatures and the current strong La Niña. They could still be correct. The National Hurricane Center’s 5-day map (as of 8-28-2022) is now showing four areas of potential development, with one area that has a 50% chance of development into a tropical depression within the next 5 days. Just in time for the peak of the season, according to the timeline we discussed earlier this month.

Why have the tropics been so quiet?

What caused the very quiet period in July and August? Hurricane climatologists point to several factors: the continuing clouds of dust that have blown off Africa and across the Atlantic Ocean towards the west, dry air moving in from Europe, which is experiencing its worst drought in 500 years, and the lack of strong waves moving off of Africa to act as seeds for tropical storm development. But the presence of warm sea surface temperatures and the lack of a strong jet stream (which is consistent with the presence of the La Niña) were expected to contribute to a stronger season than we have seen so far. If we can’t understand why this season has been so quiet so far, it means we still have a lot to learn about hurricane climatology and behavior.

A large storm in the ocean

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Tropical Storm Lisa on September 23, 2016 with African dust

The second half of the 2022 season is likely to be a lot more active than the first half, although forecasters have dropped the predicted number of storms from the early forecast due to the past two quiet months. If you live in an area affected by Atlantic hurricanes, you should be prepared for a more active pattern—don’t let the last two months fool you! If you live in another part of the world that is affected by tropical storms, you should also understand their climatology and likely impacts on where you are as well.

A body of water with a sunset

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Caribbean rain shower at Man-of-War Bay, Tobago, September 1980. Source: NOAA.

Some resources for following hurricane weather

For those of you who are fascinated by tropical storms and hurricanes, even if you don’t live in an area that is prone to them, there are a few resources that you can use to track potential storms and follow them as they develop and move through areas that could be severely impacted by them. The first site I use is the National Hurricane Center, the source of official forecasts and outlooks for the season as well as specific storms as they form. Their website has a lot of information about past storms as well as educational resources on tropical systems. You can also find a lot of maps and climatological information at Mike’s Weather Page if you just need a quick look at maps and other images related to tropical weather in the Atlantic and Pacific Basins.

On social media, I follow Bryan Norcross and Brian McNoldy on Facebook and Twitter; they may be on other social media as well. Bryan Norcross is the television meteorologist who was working in Miami at the time of Hurricane Andrew; it has been fascinating this week to follow his timeline of Andrew from tiny disturbance to monster storm as it hit Miami and then Louisiana over the past week back in 1992, thirty years ago. Brian McNoldy is a senior hurricane researcher who works at the University of Miami and has done some interesting climatological work on past hurricanes as well as provides insight on the current season. There are also plenty of great local resources for local impacts if you live in a hurricane-prone area.

A picture containing nature

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Landfall of Hurricane Michael, October 10, 2018 from earth.nullschool.net

How to visualize the wind

If you are interested in looking at the wind patterns associated with storms, both tropical and extra-tropical, then there are three sources of fascinating maps that allow you to visualize the flow of air across the United States or the world:

United States current surface winds Hint.fm/wind. This site has a current map of the surface winds across the continental United States showing the wind speed and direction in motion. It is based on a near-real-time computer simulation to provide seamless coverage across the country.

Global earth interactive wind map https://earth.nullschool.net/. This interactive map allows you to look at current winds anywhere on the earth by dragging and zooming on the globe. You can use the menu on the lower left to pick higher levels in the atmosphere; this will allow you to look at jet streams aloft as well as surface winds.

Windy global current and forecast winds https://www.windy.com/. This site provides global current and forecast winds as well as other weather information that will allow you to view the weather and plan for future weather conditions at home or away.

These sites provide you with information about both wind speed and direction. That can be very useful for gardeners who are spraying or need wind information to track where the air hitting their gardens has come from. Wind drift of agricultural chemicals also causes damage to crops and outdoor workers. Exposure to chemicals such as weed killers can affect gardens adversely, and it can be important to know where those chemicals are coming from. If you don’t have access to local wind observations, these maps can provide you with useful information.