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Jeff Ball

Back in 2006, when I first started garden writing, I was invited to give a talk in Michigan. It was really exciting to get this kind of invitation so early in my writing career and I was thrilled to have the opportunity to talk to an audience that wasn’t composed primarily of students or academics.

Looking back at those talks…well…they weren’t particularly good. Sure, there was good information, but I wasn’t particularly comfortable giving talks at that stage and so I’m not sure I got my information across nearly as well as I should have.

After my talks there really wasn’t much to do besides listening to other speakers, and so that’s what I did. That’s where I got to listen to Jeff Ball, a garden writer and self-proclaimed yardener. I was amazed at how this guy filled the room with people who wanted to hear him speak and further amazed at how well he spoke. Being in academia I’m always surprised when someone speaks without visual aids – I had always idolized Michael Dirr, my former advisor and one of the greatest speakers I know, who always played off of his magnificent slides of plants. I really had never seen anyone give a talk without slides, or overheads, or powerpoint, or a chalkboard, before. But Jeff Ball did a talk right off the top of his head with nothing else, and he was magnificent. I remember not agreeing with everything he said (can’t remember what specifically), but more importantly, I remember how the tone of his voice and his wonderful sense of timing and rhythm kept the audience interested and engaged. After that day there were two speakers who I idolized, Mike Dirr and Jeff Ball.

Jeff Ball passed away this past week. It’s always sad when someone who you know and admire passes, but their passing also provides a time for you to think back on the good things which they did. I didn’t know Jeff well at all. Indeed, I never saw him speak again after that day. But his talk was inspirational and led me to really think about how I give a presentation, and for that I can’t thank Jeff enough.

Looking for answers

“Stealing an idea from one source is plagiarism; stealing from many sources is research.” This quote has been attributed to so many people I won’t bother trying to list them here. But the point is a lot of what we do as professors is spend our time digging into the literature to look for substantiating or conflicting evidence for the ideas were interested in testing. As a grad student back in the 1980’s, a time-honored tradition was to spend the afternoon at the library combing the stacks for journal articles, loading volume after volume onto a cart and then schlepping off the library copy center. With the mechanical hum in the background and green glare of the scanner radiating off the walls, we’d wear our toner smudges like a badge of honor as the copy machine counte kept track of our progress.

Today, of course, things have changed dramatically. The hardcopy CAB abstracts have been replaced by Google Scholar and Web of Science. For those of us at major universities, hundreds of journals are available at our fingertips through on-line subscriptions through our libraries. And an electronic interlibrary loan request can usually produce a .pdf of even the most obscure reference with a couple of days. Unfortunately for those of us working in landscape horticulture some of the hardest to find journals were the ones that we often wanted most. For example, journals from the American Society for Horticultural Science (ASHS) were only available to members and just recently became open access and indexed through Web of Science and other indexes. Fortunately the situation is improving for two other sources that contain the type of applied research we are often after. Arboriculture and Urban Forestry (formerly Journal of Arboriculture) and Journal of Environmental Horticulture are both available on-line (or partly available on-line). More importantly for GP blog readers, neither requires a subscription or university log-in.

Arboriculture and Urban Forestry is available at http://auf.isa-arbor.com/

Journal of Environmental Horticulture is available at http://www.hriresearch.org/index.cfm?page=Content&categoryID=174

Both journals include a search function to make it easier to find related articles.

Leaves for Lawn Fertilizer

Yesterday I happened to see a garden calendar encouraging people to pick up their leaves so that they don’t pollute streams and lakes by encouraging algae to grow. This was a good idea, I thought, but then I started to wonder whether leaves on the lawn might not be a better idea? After all, the reason that leaves cause algal growth in water is because of the nutrients they have. And if they have nutrients couldn’t those be used for fertilizer instead of the regular fertilizers which we use? What if we raked all of our leaves onto our yards?

There’s no denying that leaves which drop in the fall can make great compost, but how well would they work as a fertilizer? So I did a little bit of preliminary research — reading old papers and such — and here’s what I’ve come up with:

Fallen leaves are very variable in nutrient content. Some leaves have 1% nitrogen, and some can have almost 3% (these are mostly from leguminous trees). In terms of phosphorus, fallen leaves tend to have around 0.1%, though once again, it’s very variable. For the purposes of this post I’m going to stick with nitrogen.

For 1,000 square feet of grass yard it takes about a pound of nitrogen per year to fertilize, even with a low input variety.

In a heavily wooded lot it wouldn’t be odd to have around 100 pounds of leaves fall in a 1,000 square foot area. At 1% nitrogen, the leaves would provide enough nitrogen for the grass, but that would probably end up being a moot point because the leaves would have a good chance of smothering the grass.

So what I’m wondering is, if we planted trees which were legumes, and had higher levels of nitrogen, and if we chopped up the leaves so they weren’t as likely to smother the grass (using a lawnmower or whatever) could we provide enough nitrogen per year for a healthy low input lawn? Personally, I think so. We would need to keep these leaves off of driveways and sidewalks because this is where they would do their worst in terms of contaminating water, but if they were just in yards — I think it might work.

Diagnosing plant problems

As an Extension Specialist working with nursery and landscape issues, I’m frequently called upon to troubleshoot problems with trees and shrubs in various settings. Sometimes it’s residential or commercial landscapes, sometimes nurseries, sometimes Christmas trees. So naturally I was intrigued when the most recent issue of American Nurseryman featured a cover story on diagnosing nutrient deficiencies in plants. The article was written by Dr. Gary Gao, Extension specialist with Ohio State University. The article http://www.amerinursery.com/article-7428.aspx is good and does a good job on covering the basics. However, the introduction of the article also hit on one of my pet peeves – and what is the Garden Professors for if not to vent on our pet peeves.

The intro states:

"If you have a good understanding of the function of plant essential mineral elements and a familiarity with common symptoms, common mineral nutrient disorders can be diagnosed quite easily."

Maybe I’m just trying to justify my own existence, but I find diagnosing nutrient disorders anything but easy. This article and countless extension bulletins and factsheets imply that you can diagnose nutrient problems simply by matching leaves from your tree or shrub to a photograph showing the same symptoms. To which I have three words: Ain’t gonna happen. For the upper Midwest, I can think of exactly two landscape nutrition problems that I would be comfortable diagnosing by visual symptoms; iron chlorosis in pin oak and manganese deficiency in red maple. Beyond those two I would want information from foliar samples and soil tests, as well as some site information before concluding the cause of a plant problem.

The main issue, of course, is that plant problems rarely come gift-wrapped. Nutrient deficiencies (or, rarely, toxicities) are often confounded with other site issues; poor drainage, excessive drainage, too much sun, too much shade, insect damage, diseases, salt exposure. As I’ve said many times, it’s much rarer to find a ‘smoking gun’ than not. Usually it’s process of elimination with a best case scenario where you can compare symptom and foliar analyses of ‘good’ and ‘bad’ plants. But I think we do a disservice to landscape and nursery professionals and homeowners to imply that identifying the cause of a problem is as simple as picking the right suspect out of a line-up.

The people have spoken…

OK, the results are in for our reader poll to design a landscape tree transplant study here at MSU next spring. And the winner is…er, I mean, winners are: Root ball manipulation and Fertilization at the time of planting. Root ball manipulation drew 74.3% of the responses, Fertilization was chosen by 63% (voters could chose more than one favorite topic). All other proposed topics were under 40% (Mycorrhizae – 37%, Crown reduction- 31%, Cambistat – 11.4%, Bioplex – 11.4%). I will put pencil to paper and survey the trees and space available for a trial. My initial thought is that we can do a 3 x 2 factorial experiment with 3 types of root-ball manipulation and 2 levels of fertilization. Root-ball manipulations will include two popular recommendations: 1 – ‘shaving’ the root-ball to remove circling roots; 2 – ‘teasing’ the root-ball to untangle circling roots; and 3 control e.g., planting the root-ball as is. The two fertilizer treatments will be 1 – 400 grams Osmocote and 2 – control, no fertilization. The goal is for this to a long-term study – hopefully at least 5-years. The principal response variables will be survival and growth. If time and resources allow we will collect water relations data such as water potential and stomatal conductance during the transplant year.

I was a little surprised that Cambistat did not rate higher. This product has been heavily marketed to arborists and has been touted to reduced transplant stress. The active ingredient, paclobutrazol, is a well-known plant growth retardant. The theory is that it reduces stress by limiting crown expansion and reducing stomatal conductance while roots continue to develop. I’ve actually been a bit intrigued and may set up a little side study to satisfy my own curiosity.

Thanks to all who took the time to vote. I look forward to keeping you all posted on the trials!

Reader input wanted for new book

(Note: I’ll be doing another blog posting later today. Just want to be sure I get this out.)

I’m writing a new book on plant physiology for gardeners – a book that explains how plants work and why they sometimes do weird and unexpected things. I’d like to hear what kind of “how” or “why” questions you’d like to see answered in this type of book. Please add your comments to this post, or send them to me directly. And if there are other gardeners you know who might want to send suggestions, be sure to send them the link!

Smoke ‘em if you’ve got ‘em…

(As an aside, I wrote this before I read Jeff’s Oct. 13 post so don’t read this as a rebuttal!)

One of the hallmarks of science is that it pays to keep an open mind. We all tend to have biases so it’s good to get a reminder once in a while that some things that seem ‘out there’ can actually work and provide some useful information.

A case in point. At the American Society for Horticultural Sciences annual meetings I make a point to wonder through and browse all of the poster presentations – even those that appear to have little relevance to issues I typically deal with. This year one of the posters that caught my eye was by Orville Baldos and his colleagues at the University of Hawaii and the USDA on the use of liquid smoke flavoring to improve seed germination of piligrass.

So first, what’s piligrass and why would you want to improve its seed germination? Piligrass is a native bunchgrass in Hawaii. It’s used for conservation and restoration projects and there is increased interested in its use as an ornamental. It is drought tolerant and fire adapted but production is limited by poor seed germination. Where does liquid smoke flavoring come in? Liquid smoke is produced by passing wood smoke through water (I assume someone somewhere has constructed the world’s largest bong to accomplish this). The water traps a variety of chemical compounds in solution, many of which are useful in giving a delicious smoky flavor to foods that have never been near a grill. Some of the compounds in liquid smoke are also useful in improving germination of seeds of fire adapted plants, or at least piligrass.

In their study Baldos et al. found that germination of piligrass seeds soaked in distilled water was a paltry 0.5%. In other words, you’d have to sow 200 seeds for each plant you hoped to produce. Soaking seeds in gibberillic acid (a common method to improve seed germination for a variety of plants) bumped the germination rate up to 20% (5 seeds to get one plant). But soaking seeds in liquid smoke did better still and doubled the germination to 40%.

At the end of the day it’s unlikely that I’ll ever use liquid smoke for anything except adding a little extra zing to my family’s secret barbeque sauce. But this study is a good example that sometimes things that make you go ‘What the heck?’ can have merit in the end. Just need to take a scientific approach and keep an open mind.

For those interested in the details here’s a link to the poster http://ashs.org/abstracts/sites/default/files/updated_ashs_poster_091911.pdf

Vote early and often!

In my last post I announced that we would be conducting the first landscape transplant experiment designed by social media. We have about 100 ‘Bloodgood’ plane trees in 25 gallon containers that are leftover from a recent nursery trial. The trees will be planted at our Hort station and receive minimal care after planting beyond an initial watering and a kiss for luck. I asked for some suggestions for potential treatments and got some good suggestions. Unfortunately, one thing I forgot to point out is that I have essentially no budget for this project. So trying to determine whether or not roots are mycorrhizal, or bringing in B&B trees for comparison, are beyond our capabilities at this juncture.

We did have some interest in determining the effects of manipulating rootballs for container-grown trees. These trees have been in pots for 2 years and I absolutely guarantee they are pot bound. Definitely a good opportunity to look at shaving or teasing rootballs.

There are a couple of other items that I am curious about.

One is crown reduction thinning. In forest nurseries trees are often top-pruned to reduce shoot-root ratio and increase transplant success. Obviously we would’t top landscape sized trees, but can selective pruning to reduce the ratio of crown area to root area reduce water stress and increase survival?

Along these lines, there is a lot of marketing of plant growth retardants to reduce transplanting stress. The most common is probably paclabutrazole – sold under various trade names including Cambistat http://www.treecaredirect.com/Cambistat-Tree-Growth-Regulator-p/3101.htm Does it work?

I’ve also been curious about hydrogels. I’ve long been a skeptic but have had several arborists tell me they’ve used them successfully – of course they didn’t leave an untreated control.

Then, of course, there’s Bioplex. http://www.bio-plex.com/pdfs/Bio-Plex2009Catalogue.pdf It might be easier to list what isn’t in Bioplex than what it contains. I suspect whatever effect it has is largely related to small amount of nutrients it contains.

Lastly, I still adhere to the notion that fertilizing trees at planting is not necessarily the source of all evil in the world and may even be a good thing. Here I get a chance to provide myself wrong and apply a dose of Osmocote in the planting hole.

OK that’s the background – time to vote. The link below should take you to a Survey Monkey survey. You can vote for more than one item, but please vote for no more than three.

http://www.surveymonkey.com/s/W3YGGSD

A Challenge

As I was looking over the label on a bag of fertilizer this morning I was reminded of the time, a few years ago, when a friend of mine and I went to a local K-mart and decided to see what the people in the gardening section knew. We started small—we went over to a bag of fertilizer and my friend asked what the three numbers on the bag meant. Now, as most gardeners know, those numbers indicate the amount of nitrogen, phosphorus and potassium in the fertilizer. Unfortunately the guy we asked told us that those numbers were actually a computer code…We never did find out exactly what this computer code was for. I have no idea why the guy couldn’t just say “I don’t know”. We had intended to ask more questions, but both of us were too stupefied to continue.

So I have a challenge for all of you this weekend—I’m curious to see who takes it up—go to a box store, or a garden center—your choice—and ask them what the three numbers on the bag of fertilizer are for. You can list responses in the comments section below—or feel free to e-mail me directly at gillm003@umn.edu if the answers are too embarrassing!

Be a Part of History!

Here at the Garden Professors we pride ourselves on being on the cutting edge of technology. In fact, we’re so tech savvy we didn’t even whine when FaceBook foisted a new homepage format on us for no apparent reason. So it’s only fitting that we offer you, Mr. and Ms. Garden Professor Blog reader, an opportunity to participate in the first ever landscape horticulture research project designed by social media.

Here’s the deal. My current research project on water and nutrient management of trees in container production has left us with over 100 ‘Bloodgood’ London planetrees in 25 gallon containers. What I need from you are ideas for a study plan on what to do with the trees next.

Of course, as with any major research project, the first step in the rigorous scientific process is to come up with catchy acronym for the study. I propose “the SOcial MEdia DEsigneD TRansplant ExpErimental Study” or SOME-DED-TREES for short. Needless to say, I am willing to consider alternatives. In any event, we have a unique opportunity to investigate post-transplanting growth, development and physiology of landscape trees.

So here’s what we have: Approximately one hundred, 2” caliper trees, grown in containers in a standard mix of 80% pine bark and 20% peat moss. Trees have been grown for two years in essentially standard nursery culture – daily irrigation and 60 grams of Nitrogen per container. The subject of the original study was fertilizer source; half the trees were fertilized with Osmocote and half received the same amount of nutrients from organic fertilizers. After two years we have not seen any difference in growth or foliar nutrients between the treatments. Nevertheless, I will need to include the prior treatment as a blocking variable to eliminate any potential confounding effects. Beyond that it’s wide open. We could have 6 treatments x 2 blocks x 8 trees = 96 trees. I strongly suspect in the final analysis the block effect will be non-significant and we can consider there to be 16 replicates, but life is full of surprises.

So, what tree establishment or tree care question is burning a hole in your brain? “Shaving” or “butterflying” container rootballs? Fertilizing at time of transplant? The latest biostimulant? Crown thinning at time of transplant? Frequency of post-planting irrigation? Width of the planting hole – how wide is wide enough? Send me your suggestions and we will set up a poll to vote for the top choices.