The Garden Professors™

The search for bogus info and products continues!

The Garden Professors, led by our warrior princess Dr. Linda Chalker-Scott, continue to ferret out bad advice, bogus information, and worthless products foisted upon the unsuspecting gardener.

I’m assisting in the hunt as well. See my survey link below. Looking specifically for :

1) Gardening-related blogs and vlogs (video blogs) that are out there – could be anywhere on the spectrum of misinformation: spewing pseudoscience or just plain malarkey. Or some of the content is o.k., but veers off occasionally into the land of the absurd.

2) PRODUCTS! I’m especially interested in this. There have been some hilariously useless things brought to our attention over the years, but new gardening products are constantly coming on the market to fill this or that perceived niche. The Amazonification of garden retail is exacerbating the problem. A brief example is a $94 compost “tumbler” that two heads of old cabbage would fill. Now roll around daily and wait… So let us know of any gardening product that you or a friend have purchased and it just didn’t work as promised (or failed in epic fashion).

Respond to Holly’s brief survey here!

All responses to my survey are confidential with no names used in the input or output, so feel free to include rants along with links. Will share what we gather in a future post (or two). Survey closes June 20, so don’t tarry. Thank you, and garden on!

Respond to Holly’s brief survey here!

Do your homework before hiring landscape help!

(A guest post by Rich Guggenheim. You can see Rich’s bio at the end of this post.)

When it comes to shopping, my friends all know it takes me a long time to make a decision. I methodically research out what I want. Then I narrow it down to a few items. After I look over my choices carefully, I may go home to get on the internet and look at consumer reviews; I may go from store to store and check out prices. I look for quality and I look to make sure I am getting a product that is worth the money I am spending on it. I want to make sure my investment will last. Sometimes, my shopping experience will last hours, days, or in the case of a car or computer, it could be months.

My yard is no different. When I need yard work done, such as lawn aeration or tree trimming, I am insistent on high quality work. As a homeowner you are the first and the last line of defense when it comes to making sure that a quality job is done, and done correctly! Knowing what to expect in landscape maintenance and being armed with a small amount of knowledge as a consumer can play in your favor.

Always hire a certified professional to do your work. Would you seek medical advice from an individual who was not licensed to practice medicine? Of course not! Why then would you do it with your yard? I recommend that you check into the individual or company before hiring them. Do some homework. How have they been trained? Where is their certification from? Are they insured, licensed, and can they provide you documentation? Are they registered with the Better Business Bureau? If so, what is their rating? Drive around and check on some of their previous work. Is it the kind of quality you would want in your own yard? Ask for references. Ask questions! This is, after all, a job interview for the contractor. Just because they are the cheapest does not mean they should get the job, and just because they slap a business magnet on the side of their pick-up truck does not mean they know what they are doing! In the following I will be talking with you about what to look for when hiring a contractor to do yard work and how certain procedures should be done. Armed with this knowledge, you will be better able to ensure the work done in your yard is of the quality you deserve for the money you pay.

Lawn aeration is perhaps one of the best things that you can do for your lawn. Done twice a year, once in the spring and once in the fall, core aeration combats soil compaction. Soil compaction is a problem in nearly 80% of all landscapes. In addition, aerating your lawn helps combat thatch accumulation and reduces the amount of water you need to apply to your lawn. The reason for this is because when your soil is compacted oxygen and water can’t penetrate into the soil. Fertilizer can’t get penetrate the soil either. As a result, roots are often shallow, and the lawn will need more frequent irrigation. (1, 2, 3, 4)

Core aeration removes small plugs, about 1-3 inches long from the soil. A single aeration using a machine with 1/2-inch diameter tines removes as much as 10 percent of the thatch if enough passes are made to achieve average 2-inch spacing between holes. Remember the key is 2-inch spacing. This may mean that multiple passes on the lawn are required. This small investment of an extra $10 will pay dividends in the end.

What do you do with the cores after you have had the lawn aerated? That really is a personal decision. Some people do not like the little plugs being left on their lawn, although there may be benefits to allowing them to disintegrate into the lawn again.

If you do decide to remove them, they are great for the compost bin. Other options may be to power rake the lawn after aeration, watering, or simply running a lawn mower over the lawn after you aerate (although this practice will cause the blades on your lawn mower to dull). Once you have aerated your lawn if you need to reseed, this is the optimum time to do it. The best part of reseeding now is there is no need to top dress the lawn, as the lawn seeds will have nice little holes in which to germinate!

Another type of aeration being marketed by many lawn care companies these days as a replacement for core aeration is liquid aeration. While different ingredients make up this popular lawn service, the main ingredients seem to be liquid humates (organic matter) and sodium lauryl sulfate (soap). These are nothing more than snake oil remedies and are no substitution for the real deal of removing the plugs from your lawn by core aerating. There is no scientific research which has shown chemical aeration to be effective. You may as well throw dirty dish water out on your lawn. (5)

The thing to remember from all of this is that you want to have your lawn aerated twice a year; in the spring, and again in the fall. The plugs removed should be 2-3 inches long, and on 2 inch centers, which may require multiple passes on your lawn.

Tree pruning is something I take seriously. It is a science which should not be left to a novice and is far more than could be covered in one article. For me, spotting a bad tree pruning job is as easy as spotting a bad haircut. The only difference is a bad hair cut grows back and has no adverse side effects on your health. However, a pruning job can have enormous effects on the health of a tree, either for good, or for bad. When you hire an arborist, make sure they are ISA certified, licensed, and insured. To find an ISA certified arborist, visit their website.

The key points for a good pruning job really come back to structurally pruning the tree correctly when the tree is young. Improper or lack of pruning when the tree is young can greatly increase the likelihood of tree failure when the tree is older. Cuts on branches larger than 4 inches increase the possibility of decay and disease. If possible, prune trees when the branches are smaller than 4 inches in diameter.

When pruning trees, it is important to prune the branch back to the branch collar. Don’t leave stubs, or what I call “hangars” where you can hang your coat. Leaving these nubs will cause decay and disease to move into your tree.

The last key component to pruning is to always remove a smaller branch back to the parent branch, never the other way around. When you remove a parent branch, unless the wood is dead, you greatly increase the risk of beginning the downward spiral of death and decay in the tree. While this is great for less reputable tree-trimming companies who will have to come back year after year to remove an ever-increasing amount of dead wood from the canopy of the tree, it is hard on your pocketbook; more importantly, your tree’s life is shortened! By knowing some pruning basics, you can ensure that you are hiring a professional who knows what they are doing, and will extend the value and life of your landscape.

Carrow, R. N., B. J. Johnson, and R. E. Bums. 1987. Thatch and quality of Tifway bermudagrass turf in relation to fertility and cultivation. Agronomy Journal, 79: 524-530.
Dunn, J. H., D. D. Minner, B. F. Fresenburh, S. S. Bughrara, and C. H. Hohnstrater. 1995. Influence of core aerification, topdressing, and nitrogen on mat, roots, and quality of “Meyer” zoysiagrass. Agronomy Journal, 87: 891-894.
Erusha, K. S., R. C. Shearman, and D. M. Bishop. 1989. Thatch prevention and control. Turfgrass Bulletin, 10(2): 10-11.
Murray, J.J., & Juska, F.V. (1977). Effect of management practices on thatch accumulation, turf quality, and leaf spot damage in common Kentucky bluegrass [Poa pratensis]. Agronomy Journal,(3), 365-369.
Lloyd M. Callahan, William L. Sanders, John M. Parham, Cynthia A. Harper, Lori D. Lester and Ellen R. McDonald.Cultural and chemical controls of thatch and their influence on rootzone nutrients in a bentgrass green.Crop Science, 1998 38: 1: 181-187. doi:10.2135/cropsci1998.0011183X003800010030x

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Rich Guggenheim is a consumer horticulture educator with the University of Idaho in Canyon County and is the program director for the University of Idaho Extension Master Gardener volunteer program. Rich is also working on a Ph.D. in plant pathology. Rich has been an horticulture extension agent for Colorado State University, horticulturalist for Disney Parks, and is the host of the weekly “Avant Gardener” radio program in Boise. He can be reached at richg@uidaho.edu

You, too, can be up to your pits in perennials!

(posted by Holly Scoggins)
The Perennial Plant Association (PPA) is a unique group of folks – comprised of plant breeders, educators, propagators, promoters, garden writers, growers, retailers, gardeners, and landscape designers – all under one umbrella. The PPA is probably one of the most vertically-integrated plant organizations out there. If it has anything to do with a perennial plant, there’s a good chance one of our members is involved.

The marvelous/legendary PPA Symposium has been held in all parts of the country. This year’s perennial-fest is in Raleigh NC. This goes back to my particular roots with the organization – my first PPA experience was in 1997 symposium, also in Raleigh, while I was grad student at NC State. Helped out in a few capacities, including tour bus wrangler (on the surprisingly rowdy bus, no less).

A special feature THIS year in Raleigh will be a one-day plant-geek-fest, open to the public as a separate registration item (of course any perennial freaks are absolutely welcome to attend the entire week of symposium events as well!).

Many/most of you are not located in the Mid-Atlantic/Southeastern region of the U.S. So why I am I touting this here? Because some of my biggest Ah-Ha! moments regarding growing and gardening have happened in places far from my comfort/hardiness zone. And the plants…oh the plants. In searching through my older GP posts, I’ve mentioned the PPA at least 9 times.

Recent examples: In 2016, the PPA symposium was in Minnesota… really opened my eyes, heart, and wallet to some lesser-known prairie species and design concepts. I probably have one of the larger Silphium collections in Southwest Virginia now. Whoops.

Last year’s symposium in Denver, Colorado brought with it awesome alpines and steppe plants – many of which I could grow here, with a bit of assistance from enhanced drainage. Of course there were also examples galore of rock gardening techniques to help make that “enhanced drainage” thing happen. Beyond the plants and gardens, another highlight is the opportunity to meet the area’s botanical movers and shakers that I wouldn’t have had otherwise. So much positive, fun energy – helps to remind me why I do this thing!

Joseph Tychonievich experiencing Perennial Overload Syndrome at the 2017 Perennial Plant Association Symposium last year in Denver. Triage included some deep breathing and a Sprite. Plant: *Dalea candida*. Place: Chatfield Farms, Denver Botanic Garden. Photo: H. Scoggins.

So…trust me when I say driving for 6-8-10 hours or hopping on a plane to the handy-dandy RDU airport will be WORTH IT. Especially if you stick around for core symposium including fab tours to private and public gardens, independent garden centers, behind-the-scenes at wholesale nurseries, and (wait for it) dinner and garden wandering/shopping opportunities at Plant Delights Nursery.

Back to the “Spend the Day with Perennial Plants” opportunity on Monday, July 30 – Check out this lineup for the plant talk day – and note the geographic diversity of the speakers – again, this isn’t just a “Southeast” thing!

– Patrick McMillan is an Emmy Award-winning host, co-creator, and writer of the popular nature program, Expeditions with Patrick McMillan . He’ll highlight Carolina native perennials for the garden in a morning talk. Later that afternoon, he’ll cover Southwestern plants we can use in the Southeast to cope with drought.

– George Coombs manages the horticultural research program at the Mt. Cuba Center in Hockessin, Delaware. This renowned botanical garden focuses on native plants, and their plant evaluations are making a big splash in the industry. Get a peek at the top-performing selections and find out what it takes to stand out in their trials.

– Christian Kress owns a specialty nursery in Austria that focuses on rare perennials from around the world. He’s traveled extensively, authored books, and introduced several beloved perennials to the market. He’ll bring the knowledge on flocks of Phlox (!) and introduce us to the amazing selections coming out of Russia.

– Judith Jones owns Fancy Frond Nursery in Gold Bar, Washington. She’ll open the world of ferns and inspire a new appreciation for their role in the landscape. [Am hopeful that frond puns will abound.]

Other presentations include iris breeder Kevin Vaughn; John Kartesz on native plant inventory software that generates customizable maps and databases; Larry Mellichamp on the world of unusual, surprising and bizarre plants; and Lauri Lawson on medicinal plants.

ALL THIS IN ONE DAY, PEOPLE.

The whole shebang takes place at the Hilton North Raleigh/Midtown. Advanced registration is required and early bird pricing ends June 1. See the program description and get registration information on the PPA Raleigh website. Be sure to check out the glorious e-Brochure just posted on the symposium home page. Hit me below with any questions – and would LOVE to see you there!

Costs and benefits of pre-plant root manipulation

Spring has sprung here in Michigan; time to get cracking on lots of projects. One of our new projects is an investigation of pre-plant techniques for dealing with root systems on container grown trees. As many of you know, Linda Chalker-Scott is advocate of bare-rooting trees before planting to correct potential root defects before planting. As some of you may know, I’m skeptical of this approach. It’s not that I think root systems are perfect – far from it. But we lack sufficient information to know whether the costs of bare-rooting (time/effort, stress on the trees) warrant the benefits. We also have little information on how species vary in responding to bare-rooting. From the experience of foresters and bare-root liner nurseries we know that some species are highly sensitive to storage and handling when they’re bare-rooted. When I worked for International Paper, we had little difficulty transplanting sycamores bare-root; whereas we often encountered severe dieback or mortality with sweetgum. Likewise, shade tree nurseries often encounter difficulty establishing oaks, baldcypress, and hackberry from bare-root liners. In fact, J. Frank Schmidt and Sons nursery, one of the largest producers of shade tree liners has discontinued production of bare-root hackberry lines and only produces them as container stock.

As I said, I’m skeptical that putting a tree through the trauma of bare-rooting is worth the potential benefit. But I’m also open-minded and willing to conduct an objective trial to see what’s what. As an aside, I was skeptical about root-shaving before we conducted our own trial and was impressed by the results. For our current study we planted 96 container-grown shade trees last week at the MSU Horticulture Teaching and Research Center. Trees includes three cultivars: ‘Bloodgood’ London planetrees, columnar tulip poplar and ‘October glory’ red maple. We assigned the trees at random to one of four treatments: Control (no root treatment), Shave (outer roots removed before planting) and two bare-root treatments – Bare root – Wash (trees were bare-rooted by washing the roots with water) and Bare root – Airspade (trees were bare-rooted using an airspade). The planting crew consisted of my technician, Dana Ellison; my new Master’s student, Riley Rouse; my undergrad assistants, Becky Pobst and Alex Love; and Linda, who was on-hand to provide quality control on the bare-rooting operations.

For her M.S. project, Riley will be tracking performance of the trees over the next two years. Her measurements will include tree survival and growth as well as measures of physiological responses such as plant water potential and photosynthetic gas exchange. Next fall, after two growing seasons, we will dig a subset of the trees with a tree spade and inspect the root systems to determine the effect of treatments on root system development. In the meantime, here are some photos from last week’s festivities.

Right tool for the job. MSU Beaumont Nursery provided a big assist by augering the planting holes.

Alex cleans up a planetree with the airspade

Riley washing up a maple – don’t worry the cicling roots come off next…

Light and easy. Becky after airspading a tulip poplar

Wait’ll purchasing sees this… A wading pool is perfect for pre-soaking roots before washing and for storing until planting.

Getting a little kinky… Root at the end of the felco’s bending back on itself – corrected after the photo-op.

Looking a little wilty. TheBare-root maples required the greatest root removal and correction

Trial plantation at the end of the planting

Can’t pull off something like this without an awesome crew!

My New Project — The Plants We Eat

By Jeff Gillman

I love stories, and my favorite stories, as you might guess, are true stories about plants. One of the things that I’m best known for here at the UNC Charlotte Botanical Gardens is telling random stories about some odd tidbit or another to students trapped in my classes or visitors locked into garden tours, but recently I found a new way to share my collection of those eclectic plant stories: Podcasting. Not only do I get to talk about all the things that I love to talk about, only those people who really want to hear about them have to listen. It’s a win-win!

From apples and artichokes to digitalis and peyote, our world is full of amazing plants that we interact with on a daily basis. This greenery can sustain us, intoxicate us, cure us of disease, and even kill us.

I have had the opportunity to read about and work with an incredible variety of plants, but the ones that I find most fascinating are those we ingest as food or medicine, and that’s what this podcast is about. From toxic honey made from Rhododendrons to the incredible photosynthetic efficiency of sugar cane and the natural genetic modification of sweet potatoes there are an incredible number of stories that the plants around us have to tell, but if you’re just interested in growing these plants then we have you covered there too. I am doing these podcasts with a friend of mine, Cindy Proctor, who loves to talk about how to grow these plants, so there’s plenty of that in the podcast as well.

Rhododendron from which Mad Honey is made

So to make a long story short, we would love it if you would take the time to listen to our podcast. You can find it on the podcast app on your iPhone or on Sound Cloud, or here at the Botanical Gardens website.

And since we’re new at this we would love it if you would let us know what you think. You can comment on the blog post here, or on the post on Facebook, or feel free to write to me at jgillman@uncc.edu.

It’s all about location, location, location

Whenever we (the Garden Professors and our community) answer garden questions, we almost always will ask the location of the garden. I’m sure this frustrates some people who think that plants act the same wherever they are. However, this is not the case. There isn’t a one-size-fits-all to most garden questions.

For example, I work on the east side of Nebraska in Omaha, along the Missouri river. The environment (weather, soil, etc) here is vastly different than where I’ve spent most of my life in West Virginia. I had to re-learn how to answer questions when I moved. The soil pH is different (I’m still lamenting the fact that I can’t grow blueberries in Nebraska), the precipitation is much lower. Even now when I appear on the statewide gardening show Backyard Farmer, I have to keep in mind the location of the incoming question. The western side of the state is even drier than the eastern side, the growing season much shorter, and recommendations are vastly different.

The difference of where plants can grow and can’t is even more apparent when you travel to vastly different climates. I recently came back from a trip to the tropical paradise of Costa Rica. Many of my traveling partners and friends back home were blown away with the abundance of plants growing in yards, farms, and even in the wild that cannot grow “back home.”

The most common bedding plant in lawns were a popular holiday favorite here in the states – amaryllis. They were planted in abundance along sidewalks and driveways.

Amaryllis prolific in a Costa Rican yard

I visited a diversified coffee farm that was using Dracena (a common houseplant) as living fence posts in their vegetable garden. (And did I say coffee farm – nothing like drinking a farm fresh cup of coffee right on the farm).

Living Dracena fence posts at a Costa Rican coffee and vegetable farm

Tillandsia air plants were growing like weeds (which is basically what they are) on the trunks of trees.

These are all tropical plants that won’t survive in colder or drier climates of the US. (The southern US states can grow more tropical stuff, but is is a small portion of the country.)

Many of the plants we grow both indoors and out here in the states come from different areas and grow differently in those areas than they do here. Our vegetables come from all over the world. So do our flowers and houseplants.

Plants from warmer areas either have to be grown indoors or as annuals even if they are perennial or evergreen in their native environments.

This is why the location of your garden, environment, and even the microclimate in your yard is important to know when selecting plants. Aside from the difference of what can grow, plants grow much differently in Florida than they do in Minnesota or Virginia. And why it is important information when you’re asking questions about how to grow plants or control insects and diseases – because its all about location, location, location.

Master Gardeners at a crossroads

{Warning. Today’s post is a rant. So I’ve illustrated it with pretty flowers in soothing colors to make it more palatable.)

Anyone who gardens in the United States will be familiar with Master Gardeners. The Master Gardener program was started by Washington State University in 1971, when Extension agents in the largest urban counties found themselves overwhelmed with questions from the gardening public. These agents proposed training volunteers to help with educational outreach efforts, and with support from the university the first Master Gardener program was born. The history and function of Master Gardeners is further detailed in a couple of articles I co-authored (Chalker-Scott and Collman 2006 and Chalker-Scott and Tinnemore 2009): the more recent article also raises concerns about the decline of programmatic support in Washington state and elsewhere. If you’re a Master Gardener, the repercussions of this should alarm you.

What makes a successful Master Gardener? According to Sharon Collman, the last surviving founding agent of the WSU program, it begins with this:

A commitment to basic and advanced training program;
An open-minded approach to continuing education of themselves as well as others;
A willingness to provide science-based, unbiased information regardless of personal beliefs. (From Chalker-Scott and Collman, 2006)
Pink fawn lily

To be successful, volunteers need high-quality education consistently provided by university discipline experts. And that’s where the model is starting to fail in Washington state. Extension specialists who used to provide training to Master Gardeners in plant pathology, entomology, lawn and turf management, soil sciences, and other important fields have not been replaced by the university when they resign or retire. More and more training is left to the devices of individual counties, whose Extension funding from WSU has been gutted over the decades. The previous university-centric approach to Master Gardener training has devolved into volunteer-driven county programs with little educational oversight.

While counties should be commended for keeping programming alive in the face of crippling budget cuts, the lack of meaningful curricular oversight by the university means that volunteers often don’t get the most current and relevant information pertaining to the science of gardening. Worse, they may be taken in by popular products and practices with no basis in science. Other volunteers may let their personal beliefs interfere with their pledge to provide objective, science-based information on topics including pesticides, GMOs, and other controversial topics. This undermines the credibility of the county program and ultimately the university who claims these volunteers.

If you are a Master Gardener in Washington state or anywhere else in the U.S., it’s really incumbent upon YOU to insist that your land-grant university live up to its public outreach mission. You DESERVE access to Extension faculty specialists whose primary focus is to educate the gardening public. The university takes credit for your volunteer hours when they make reports to the state legislature. Make them earn it.

Don’t waste your time contacting the university – you’ll get nothing but platitudes there. The place for change to start is with your elected state representatives.

Arbor Day of Horrors

Happy Arbor Day! What, you aren’t celebrating? As a recent transplant to the state of Nebraska, I was amazed to learn that the Cornhusker State is the birthplace of the day we set aside to celebrate trees. (Since most people associate the state with corn, football fanatics, and steak). And since Arbor Day is near and dear to Nebraska, it is the only state that celebrates it as a civic holiday (most state offices were closed – no drivers license for you!).

The holiday got its start in 1872 when J. Sterling Morton of Nebraska City, Nebraska (just 40 miles south of Omaha) organized the planting of one million trees in the state of Nebraska on April 10. Morton had been a newspaper editor, acting governor of the state, and after he founded Arbor Day was the 3rd US Secretary of Agriculture, having been appointed by President Grover Cleveland.

He built a mansion in Nebraska City that was later remodeled by his son Joy Morton (who had lots of money since he founded a little company called Morton Salt – maybe that’s where the anecdotal info of using salt to kill tree stumps/weeds started!). These days the mansion is part of the Arbor Lodge State Historical Park. The Arbor Day Farm is also part of the park, where locals and tourists alike stop for apple orchards, a tree playground, and wine tasting.

The modest Arbor Lodge, as captured when we were being tourists in our new state.

But if you haven’t planned a trip to Nebraska City for Arbor Day and you want to celebrate it at home by planting your own tree….well, there are some definite right and wrong ways to do things. So I thought we’d invite people to share their tree horror stories.

What have you seen that just makes you go huh? Do you have stories or pictures that are worthy of the carnage over at Crimes Against Horticulture?

Like the always frightening Mount Treesuvius? (down with Tree Volcanoes!)

A tree volcano (source: extension.msstate.edu)

Mt. Treesuvius Erupts (source: bygl.osu.edu)

Or how about the girdling root stanglehold of slow death?

Have you seen poorly planted, improperly pruned, damaged, or scary trees? Share your stories, pictures, and laments with us.

When spring is delayed

Enjoying our first day above 55 F in quite a while here in mountains of Southwest Virginia. We’ve had far-below-average temperature and three significant snow events over the past four weeks.

Saturday, April 7, 2018 at our farm (Newport, VA). Not making me want to garden.

For much of the Mid-Atlantic, Northeast, and Midwest, spring has been very slow to arrive. The jet stream has been riding mighty low, and is taking another dive next week. For gardeners, this is frustrating (see above), though here in USDA Hardiness Zone 6b, we’re still well within the “last freeze” window.

For ornamental plant nurseries, greenhouses, and retailers/garden centers in these regions, this is darn close to devastating (the South has fared much better). For growers and retailers, spring is the busiest time of the year – many see 70-80% of their annual sales between March and early June. Of that amount, at least 50% of retail garden center sales will happen over the weekends. IF it is nice. Folks stay away in droves when the weather stinks. And this has repercussions down the supply chain.

Chris Beytes, the editor of GrowerTalks and GreenProfit (two highly subscribed-to publications within the greenhouse and garden center sector), has been keeping track of spring sales for years.

Growers and garden centers self-report a weekend rating on a scale of 1 (dreadful) to 10 (can’t keep product on the shelf, happily exhausted, planning vacation in Tahiti). Not all states end up represented – either they’re too busy selling (Florida!) or too depressed to report (possibly Ohio!).

Here’s last week’s map (click for a link to Chris’s newsletter column)

Lots, lots of gray.

Closer to home: I took my Ornamental Plant Production and Marketing students on a field trip last Friday. We toodled up I-81 to visit a container nursery (woody plants) and a wholesale greenhouse focused on quality bedding plants and baskets for the independent garden center (IGC) market.

The greenhouse was absolutely packed to the gills with market-ready annuals, herbs, veggie transplants, and hanging baskets.

And it was eerily quiet.

A Friday afternoon in April, and the only folks in a wholesale greenhouse…were the owners. THIS IS NOT NORMAL. There should be workers, carts, trucks, beeping, yelling, transplanters cranking, etc.

Weather over the previous weekend and early week had been spectacularly crappy. Because the garden centers across the region had not moved enough product to restock, there was no shipping. Because there was no shipping, there was no space freed up to put anything else. Because there was no space, no transplanting could occur, and seedlings/liners were still in their trays. Calls were probably being placed to the propagation greenhouses that grow the plugs/liners, asking them to hold off on shipping until the finishing grower could clear out the backlog of plug trays. Plus perfect plants stay perfect only so long. Pesky things tend to grow/flop/get pests and pathogens.

I love for students to see the real-world hustle/bustle/insanity of spring that growers face each year. The act of growing plants is what sparks the interests of the students – but understanding the supply chain and market behavior is just as important. We did get great tour – along with a lot of fodder for class discussions.

Hopefully things will warm up; garden centers across the regions will be jam-packed, and all will be well. If this paralysis continues much longer, the window of opportunity will start closing. It gets warm/hot, schools let out, folks go on vacation…and lose that got-to-garden feeling.

You can help repair this logjam (yes you can!). Regardless of the weather this weekend (because you’re a tough cookie/Garden Professors reader), get thee to your favorite garden center or retail greenhouse this weekend. And buy! Buy! Buyyyyy!

Let’s be rational about roots

One of my colleagues alerted me to a blog post on tree myths currently making the rounds on social media. As a myth debunker myself I was particularly intrigued by the last myth “Root Pruning Stimulates Root Branching:”

“When planting a tree’s root ball, It is very tempting to cut back on roots that are circling the ball. It is very often thought that a dense root ball will stimulate new feeder root growth…but that is not the case.

“Don’t worry about encircling roots as they will correct that on a new site.

“Most new root growth occurs at the end of existing roots. Root pruning is often done at the nursery to accommodate packaging and to resume growth before the final sale. If you are planting the tree at its final site, it may be best that you gently break up the root ball but never prune root tips.”

Most surprising of all was the statement at the end of the post which cited an Extension publication by Dr. Ed Gilman at the University of Florida.

Let’s straighten this out (pun intended).

First of all, root pruning DOES stimulate new root growth. It’s just like the response you see when you prune the crown of a plant – the buds below the cut become active and develop into new shoots. There are growing points behind the cut ends of roots which act in the same manner.

Second, circling roots will NOT correct themselves after planting. If they are flexible, you can tease them out to radiate from the trunk. If they are woody, you will have the same luck straightening them as you would in straightening a dowel. If anything, it’s going to break. Not bend.

Seriously. You think this root is going to straighten out?

Finally, root elongation (growth) DOES occur at the end of existing roots – IF they are intact. If they’ve been cut, then we’re back to my first point.

This is basic plant physiology. The response of roots to pruning has been known for several decades. So how could the University of Florida publication be so wrong?

Excessively long roots can easily and safely be pruned before planting

I was able to track down the publication “Dispelling Misperceptions About Trees“. It was written in 1991 and has since been archived – meaning that it’s not considered to be a current source of information any longer. But let’s take a look at what it says, especially the underlined portion:

“Root pruning does not stimulate root branching all the way back to the trunk. Roots are often pruned before moving a tree in hopes of creating a denser root ball.However most root growth after root pruning occurs at the end of the root just behind the root pruning cut, not back toward the trunk. Therefore, dig the root ball of a recently root pruned tree several inches beyond the location of the root pruning. Root pruning should be conducted 6 to 10 weeks before moving the tree. Root pruning more than 10 weeks before moving the tree will reduce the advantages of pruning, because regenerated roots will quickly grow outside of the root ball.”

Root pruning when these trees were dug results in many new flexible roots

This says exactly what I stated in my first point: root pruning stimulates new root growth – which is root branching.

Dr. Gilman’s document goes on to say:

“Roots circling around a container do not continue to grow in a circle once the tree is planted in the landscape. Roots frequently circle within the perimeter of a container several times before the tree is planted into the landscape. The portion of the root which grew in the container does not straighten out, but new growth on this root will not continue to circle.”

So yes! You DO need to worry about those circling roots!

Circling roots turned this crape myrtle into a crap myrtle (Courtesy of Roger Duvall)

In 1991 Ed was an assistant professor at UF and went on to write hundreds of Extension publications and research articles during his career. And in 1991 he was well aware of how root pruning affects root growth.

The moral to this story: read your sources carefully and cite them accurately. And if what you read doesn’t jibe with the current state of science, ask questions!