Disappointment

Yesterday evening I took my older daughter to dance class while my wife stayed home.  While she was entertaining our younger daughter, the TruGreen guy came to the door to tell us that we had weeds in the yard (Damn, I had no idea!).  He went on to tell my wife that we really needed to use his company to get rid of them.  I was so disappointed that I missed him because I wanted to know all about what he had planned for our yard.  Many of our neighbors use TruGreen and I have to say that I’m not particularly impressed.  It’s not that they’re not professional — they certainly are.  It’s not that they don’t do things by the book — they certainly do.  It’s just that the book that we use is getting a bit outdated.   When I read TruGreens online FAQ it looked like they actually plan six applications of chemicals per year.  I’m assuming (I don’t know this for sure), that at least four of those include herbicides to one extent or another.  It looks like people who have no tolerance for weeds should love TruGreen.   But really, how many weeds should people allow in their yards?  Is it one per square foot? Two? Five dozen?  And what are weeds?  Is clover a weed?  At what point do we say enough is enough and that we’d rather just cope with a few weeds than hose down our whole yard with herbicides.

After reading my own words I feel like some kind of radical.  In my job I tend to see two types of people, those who can’t stand pesticides and those who can’t stand weeds.  One group is happy to spray five times a year if it means that their lawn will be weed free, and one won’t touch an herbicide.  I’m not sure that either group is correct.  I tend to handle weeds in my yard the same way I handle haircuts – I hate having my hair cut so I don’t go to the barber that often, but I do go to the barber eventually because my hair looks pretty ridiculous if it grows too long.  I feel the same way about weeds (specifically dandelions) which infest  the grass in my yard.  I prefer not to add herbicides, but there’s a big weed bank in the area and so I end up needing to apply once every two years or so because otherwise it looks pretty bad.  Rather than making either the making the weed-free lawn or the no-chemical group happy though I think that it just pisses them both off.  They see my unwillingness to commit to one way or the other as a cop-out rather than reasonable moderation. What do you think?

Surviving the desert with beauty and efficiency

I’m away this week for an out-of-state seminar and a little annual leave.   Some of my favorite places to visit this time of year are the high deserts of California.  Today we hiked to Horse Thief Creek, a relatively easy trail in the Santa Rosa Wilderness.  It’s the perfect time of year to see the high desert in bloom, especially with last winter’s substantial rainfall.

In graduate school I became interested in environmental stress physiology, and I still am entranced by the plant kingdom’s ability to overcome nearly every environmental extreme on earth.  Desert ecosystems are particularly harsh, as rainfall is limited to a short period of time, often in the winter or spring.  While many perennials are able to tolerate the subsequent dry season, annual species cannot.  In essence, they escape drought stress altogether by existing only in seed form for most of the year.  Seeds contain relatively little water anyway, and are so protected against environmental extremes that they can remain viable for decades or even centuries.

But back to our desert.  After the rainy season, seeds of annual plants go into overdrive, germinating, growing, setting seed, and dying back all the span of a few weeks.  Thus, the lucky hiker can find an abundance of tiny, brilliant desert annuals when seasons and vacation schedules coincide.

Tomorrow it’s the Salton Sea.  Not sure what we’ll see in terms of plant life, but we’re hoping to catch some of the migratory waterfowl on their journey north.

 

 

 

 

Products!

Just returned from a mega field trip across the state of Virginia with my Ornamental Plant Production & Marketing class. We toured major wholesale nurseries, greenhouses, and retail garden centers over the course of three days. The trip went well, I believe (university field trips are a considered a success if you return with the same number of students you left with).

One over-arching trend is, of course, that growers and retailers are going after the veg/fruit thing in a big way. Bonnie Plants has been one of the few vegetable transplant growers for the big box stores; now others are getting in on the act. Wholesale growers who traditionally supplied woodies and perennials to independent garden centers are including veg plants and herbs in their product mix.

Even the packaging is changing from the ubiquitous paper cup or poly 6-pack.  Coconut fiber (coir) pots are a step up from peat pots – they hold up better for the grower and garden center but are still plantable or compostable.

'maters

I can’t decide whether these pre-planted bean cages are ridiculous or genius. The students rated them “very cool”.  But how many beans can you get off of three plants?

bean thingies

Take some galvanized tomato cages, paint them bright colors, and charge three times the usual price. Who on earth would go for this? Oh wait, that would be me. Two. In orange. Cram ’em in the van, people.

I must have eet

Getting Loaded

Spring is off to a warm and fast start here in Michigan.  March was unseasonably warm and the past week or so has seen temperature 20 degrees above average or more.  Needless to say this is pushing all of our landscape trees and shrubs.  Forsythia and saucer magnolia are in full bloom, at least two weeks ahead of schedule.  The warm weather also has us scrambling to get some research projects in the ground as well.  Today I was working with members of my lab to install a trial to look at the relationship between fertilization in the nursery and subsequent of shade trees in the landscape.  For the past two years we’ve grown Acer miyabei (‘State street’ maple) and ‘Harvest gold’ Linden trees in 25 gallon containers as part of a trial on controlled release fertilizer.  Interestingly, in the nursery we saw a significant increase in chlorophyll index and foliar nitrogen with fertilization (no surprise) but no difference in caliper or height growth (somewhat of a surprise).  This indicates that in the nursery, fertilization induced ‘luxury consumption’ or an uptake of nutrients beyond what the trees need to meet their growth requirement.  This observation provided the opportunity for our current, follow-up study.  In the forest nurseries there is a growing interest in the practice of ‘nutrient loading’ seedling trees before they are lifted.  Forest nursery managers deliberately induce luxury consumption by fertilizing late in the season.  At this time seedlings have set a hard bud and won’t grow but can take up additional nutrients.  Numerous studies, particularly by Dr, Vic Timmer and his associates at the University of Toronto have shown that nutrient loaded seedlings will outgrow standard seedlings when out-planted on reforestation sites; even though the seedlings are the same size when transplanted.  How does this apply to large-caliper shade trees?  We don’t know.  There are certainly some underlying commonalities that are intriguing.  Nutrient loaded forest seedlings have an advantage when planted on tough sites where follow-up culture is minimal – basically the seedling has to get by initially with its own energy reserves and resources.  Shade trees planted as street trees often face the same hardship; once planted they may receive little or no after-care beyond an initial watering.  Could nutrient loading provide a better internal nutrient reserve and jump start the re-establishment process for street trees like it does for the smaller forest cousins?  We should gain some insights this summer and next.

Friday investigation – April Fools!

I didn’t exactly cheat on this one…but it was a mean trick nevertheless.

This is a contorted cultivar of Larix (can’t remember the exact name and I’m out of town this week), hence the twisty needles.  And indeed the tree is senescing.  The newer growth (the second flush of the season) just wasn’t as prepared for fall as the older growth, which is yellowing naturally.  So everything is just peachy with this tree.

Just goes to show you how important it is to know all the details when doing distance diagnosis!

 

Haber and Bosch

There are people who are fascinated by plants and people who are fascinated by the science of growing plants.  While I love plants I must confess that I consider myself to reside more firmly in the latter group that the former.  I do love to see the beautiful flowers on an apple tree in the spring, but I’m more fascinated by the nitrogen, phosphorus, potassium and other elements that the tree obtains from the soil.  I like to contemplate the complex ecosystem that surrounds the tree, including the tree’s pests and the possible things that we can do to protect the tree from pests.  I love to learn about insecticides, herbicides and fungicides, and I especially love to learn about alternatives like beneficial insects that may be used to control pests.  Histories that cover fertilizers and pesticides are pleasure reading.

One of the most important things to ever happen to the world as we know it was the discovery of a process to take nitrogen from the air so that we could use it as a fertilizer.  During the 1800s we discovered that applying nitrogen to our soils made plants grow really fast.  Though this nitrogen could be supplied with manure we quickly learned that Peruvian Guano and Chilean nitrates had more concentrated nitrogen and so less needed to be added to fields to get bigger responses.  Incidentally we could also use the nitrogen from these sources for bullets and bombs.  Nitrogen is a cornerstone of most conventional explosives.  Unfortunately these sources of nitrogen did have a drawback, they are not renewable resources.  You may say — Hey, Guano’s renewable! — But you’d be stretching the truth.  You see, guano is aged manure where the nitrogen has had a chance to become concentrated.

Anyway, by the time the 20th century rolled around we had used up much of the nitrogen available from South America and so we (and by we I mean the world in general) were hurting for nitrogen — particularly Germany.  Germany had a feeling there was going to be a war and she needed a way to get nitrogen other than sailing all the way to Peru or Chile.  So she put money into research.  Pretty soon two researcher, Haber and Bosch, came up with a method to take nitrogen directly out of the air and make it into ammonia.  Once present in ammonia it could then be used to make any number of other nitrogen based compounds, from fertilizers to bombs.

Coincidentally, Haber is also known as the father of chemical weapons.  He led the German poison gas program and had a hand in developing such things as mustard gas.  He was considered to be a patriot, but, born a Jew, the rise of Hitler wasn’t good for him and he was forced to leave in the early 1930s.

The story of Haber and Bosch is absolutely fascinating, not only because of the colorful characters, but because their discovery is, arguably, the most important factor in the increase of the worlds population over the last century.  The best book that I know of on this topic is Enriching the Earth by Vacliv Smil.  It’s a great book, but it does get a little technical.  But  my dad (he’s a chemist) showed me another book yesterday that is much more entertaining and readable than Smil’s book while retaining most of the pertinent science.  It’s called The Alchemy of Air by Thomas Hager and, if your interested in fertilizers and the people who first developed them, then this is a must read.

 

Building healthy soils?

I love living in Seattle…but I’m getting increasingly impatient with the City’s “Building Healthy Soils” propaganda.  For years I’ve questioned their recommendation to perpetually amend landscape soil with organic material to no avail.  Let’s see what you all think of their “fact sheet” (which you can read here in its entirety).

“The best way to improve the soil is to add plenty of compost or other organic matter throughout the entire planting area before planting. Thoroughly mixing these materials deep into the soil helps provide water, air and nutrients to plant roots.”

Hmm.  No mention of how to determine IF your soil needs improving; without a soil test, you have no idea what your baseline organic matter level is.

But perhaps this recommendation is only for vegetable gardens and annual beds?  Nope.  In the next paragraph, we’re told to “Mix in organic material before planting lawns, perennials, trees and shrubs.”  We’re given helpful how-to instructions:  “Use a shovel or digging fork to mix amendments into the top 6 to 12 inches of soil. It is important to amend the entire planting bed — not just small holes for each plant. When planting individual trees and shrubs in lawns or existing beds, amend an area at least 3 feet wide, or 3 to 5 times as wide as root balls over 12 inches in diameter. Rototill large areas where digging is impractical.”

Now we’ve got a serious problem.  This practice is recommended for existing beds.  Not only will extensive digging or rototilling destroy any soil structure you might have, it will also take out the roots of any desirable plants in the vicinity).

But let’s continue to ignore reality and go on to the annual recommendations for adding compost to soils.
“Clay soils: 16 cu. feet (.6 cu. yard) = 2 inch layer of compost for new gardens. Use 1 inch per year in established gardens.”
“Sandy soils: 24 cu. feet (.9 cu. yard) = 3 inch layer of compost for new gardens. Use 1 – 2 inches per year in established gardens.”

Is the compost used as a mulch in these existing gardens?  No – the guidelines are prefaced with this instruction:  “Gardens: mix compost to 10- to 12-inch depth.”  (Can’t say this does much for promoting root growth either.)

This document shows a breathtaking lack of understanding of how landscapes function, especially over the long term.  It takes an agricultural practice (annual organic amendment of crop fields) and misapplies it to permanent landscapes.  It is devoid of the research which continues to show that improper soil amendment can cause serious problems such as soil subsidence, perched water tables, and nutrient overloads.  This last point is especially important to anyone living near aquatic ecosystems, since excess nutrients always end up in the water.

Before you plant this year, find out what your soil needs before amending it.  And remember that mulching is the natural (and sustainable) way to add organic matter to the soil.

Devious dandelions

As Austrian reader Johannes explained, the difference in dandelion flower height is due to herbivory – in this case from a lawnmower.  Dandelions are quite adaptable to variable environments (the phenotypic plasticity Johannes also mentioned) and flower heights will increase or decrease depending on these variables. This ensures that the flowers will be accessible to pollinators, yet not decapitated by lawnmowers.  It’s just one of the fascinating traits that make weeds successful!

 

A Taraxacum teaser

It’s spring and the dandelions are happy to see you!  I’ve taken photos of two groups of dandelions just footsteps away from one another. The populations are both in full sun, with similar types of soil and water availability. You’ll note that one group has very short flower stalks, while the second has longer stalks:

So what’s responsible for the difference in flower stalk length?  And for extra credit, what’s the scientific term for the phenomenon?

If this isn’t something you’ve noticed before, you will from now on!  Answers Monday!