This year Pinellas county in Florida banned the use and sale of nitrogen and phosphorus fertilizers for lawns between June 1 and September 30. Is that a good idea? On the surface it seems like a great idea because it should reduce the amount of nitrogen and phosphorus which reach streams, lakes, ponds and rivers and cause algal bloom and destruction of water habitats. On the other hand a PROPERLY fertilized lawn is less likely to have nutrient rich runoff (because of a more expansive root system.) If this ban inadvertently stops people from properly fertilizing there is the possibility that the problem could be made worse.
I’m no fan of heavy fertilizer use by homeowners — I loath the practices of many lawn care companies which includes pesticide and fertilizer applications as many as 5 times a year — but the truth of the matter is that grass actually does a good job of grabbing nutrients that are applied to it because it has such a dense root system. Crops like corn and wheat, on the other hand, don’t have such a dense root system. I recently read a paper stating that, worldwide, only about 33% of the nitrogen applied to crops is actually used by those crops (this is referred to as NUE or Nutrient Use Efficiency). A recent graduate student of mine found that the NUE for Hazelnuts is actually well below that.
My personal preference for lawns is that we start to do what was once common back in the ’50s and before — plant clover with your grass. Believe it or not you can get an amazingly dense lawn that way. The clover will provide much of the nutrition that the grass needs — and it’s not, as of yet, considered a noxious weed. I also like the idea of planting leguminous trees, like black locust (I know some of you see this as a weed — it can be a nice tree too) in turf plots, reason being abscized black locust leaves have high concentrations of nitrogen — over two percent — unlike the leaves of things like maples and oaks. Of course it’s also possible for the nutrients from clover or the leaves from black locust to end up where they shouldn’t, but because of their slow decomposition we hope that nutrients running off from these sources would be less of a problem.
Anyway, my final thought — Why couldn’t we legislate that all grass seed include some clover or that a certain number of leguminous trees be planted near turf plots rather than trying to control the use of fertilizers?
I love patents. In fact, I once wrote a novel based on a patent — It was called Patent 22 — If you look this patent up you’ll just find a piece of paper from 1915 which says, essentially, that a search was made for the patent but that it couldn’t be found. No one wanted to publish it — and reading it now I do realize that it does need some serious work. Still, I think this little tidbit gives you a little bit of an idea about my interest in patents. (The paper on file at the patent office is below):
Anyway, here’s the thing that people don’t know. There are three ways to protect a plant from someone else “stealing” it: Plant Patents, The Plant Variety Protection Act, or a Utility Patent (which is what you or I usually think of when we think of a patent). The Plant Patent Act passed in 1931 and it is the way that most plants are protected today. Plants like the Honeycrisp apple which are propagated vegetatively (using cuttings or grafting) are usually protected with this type of patent. The second type of protection is the Plant Variety Protection Act of 1970. This Act lets you protect seed propagated plants. With these two types of protection you wouldn’t think that any other type would be needed — but the Supreme Court has twice ruled that plants can be protected using Utility patents (once in the 1980s and once in the early 2000s). So, what is the problem with that? Well, basically, the problem with that is that, while the other ways to protect plants allow for the use of those plants in research or for breeding and farming, using a utility patent prevents anyone from using the patented plant from doing anything with that plant without permission from the patent holder. And, basically, an entire species of plant can be patented — it has been done before with a bean that someone brought from Mexico into the US — he cornered the market on the bean and noone could sell or breed the bean without his OK. Sounds insane doesn’t it? Just my first thought on a cold Thursday morning.
Some odds and ends today that I either #1 was asked to post or #2 couldn’t resist posting. First for the picture that I was asked to post.
This, as far as we can tell (we being myself, my technician, and our grounds department), is the American elm tree that was being planted in that picture from 1909 which I posted on January 21. Dutch elm disease was devastating here in the mid 1900s as it was everywhere, but this region of the world was lucky and there were a number of escapes — and resistant trees (that’s an ongoing project of mine — working with DED resistant elms — I’ll probably post more about it this spring). Anyway, the tree is a little smaller than I would normally expect for an elm of this age, but the proximity of the road and sidewalk could easily have stunted its growth.
Now for the stuff that I can’t resist posting — mostly having to do with Bert’s post on January 25. Chad (my technician — if you follow the blog you’ll remember him, 6’4″ — etc.) was showing me a book titled Shade-Trees in Towns and Cites by William Solotaroff published in 1911 and it had this great shot of filling a tree cavity. So here it is:
The book also had a great shot of what they did to a trees canopy before they planted:
This type of pruning isn’t necessary at all. When trees are planted they adapt to the amount of roots which they have by producing fewer, or smaller leaves.
Here is a photo of the leaves of a freeman maple which was severely rootpruned right before planting and, below it, the leaves of a similar maple whose roots were left pretty much intact (both plants were container grown).
As you can see, trees have their own methods of dealing with root loss — no need for us to come in and clip their tops off. Now, two years later, both of these trees (and all of the others in the research plot) look pretty much identical.
The thing about being a horticulturist and a professor is that you’re always supposed to have the right answer. Which is to say, when I tell people not to use beer as a fertilizer, to avoid planting trees too deeply, and to reduce pesticide use, people take it for granted that I know what I’m talking about and that, if they don’t do what I say, there could very well be problems. But, as most of you know, growing plants is an art and a science, and sometimes plants decide to do things that are unexpected — plants are individuals after all, just like we are. Anyway, I was reminded of this today by this image of trees being planted on the St. Paul campus of the University of Minnesota in 1909.
How many things can you find wrong with the practices in this picture? And yet this ended up being a successful planting. I like to think we, as horticulturists and researchers, do a decent job of figuring out the best practices for planting and caring for plants, but the truth is that each plant is an individual and every situation is different and so often our predictions end up being wrong. And I think that’s a good thing.
Transgenic plants have been with us for well over a decade now. I have had the opportunity to work with many of the tools used for this technology, though most of that is far behind me (over 15 years now since I “ran a gel”) — I’m much happier being outside or even in front of a computer writing than in a lab. Fortunately I have a number of “lab rat” colleagues so I’m relatively up to date on what’s going on and what “gene-jumper” scientists can and can’t do.
To make a long story short, over these years transgenic plants have proven to be useful in some cases (by reducing the use of certain dangerous pesticides), and concerning in others (because some genes have escaped cultivation). I’m not going to go into the crazy ins and outs of the benefits and drawbacks of genetic engineering here except to give you my general opinion which is that every case needs to be handled individually. I do not believe that this engineering is, in and of itself, a bad thing. That said, I do believe that genetic engineering could get us into trouble if we’re not careful.So, with that little disclaimer I thought I’d mention something that I question — I’m not going to call it bad — but maybe it is. There’s an “artist” at the University of Minnesota — Eduardo Kac, who had some of his genetic material placed into a petunia so that some of the proteins from his body were expressed along with the petunias. I don’t have a picture of the petunia itself, but here on the St. Paul campus of the University of Minnesota you can see this structure, created by Kac, which is a graphic representation of a protein from the petunia.
(It was around 20 degrees outside when I took this shot — positively balmy compared to what it’s been like).
Anyway — as I said above — Though I have some concerns, I’m not opposed to using biotechnology for the “good of man.” Nor am I afraid that Kac’s creation is dangerous — from what I know it was kept in a closed system and the petunia was ultimately destroyed — not that it would have been particularly dangerous even if it had been released. But….to me anyway….This seems like a frivolous use of a powerful tool (that tool being the ability to move genes from one organism to another). I don’t know if I’d call it bad….but the words Wasteful and Inappropriate come to mind.
By the way, though I know less about it, it seems that Kac also transferred genes into a rabbit for the sake of art. But this is, after all, a horticulture blog so I thought I’d stick with plants!
As some of you know, I post a research update every three months or so on Susan Harris’ blog www.sustainable-gardening.com as well as on GardenRant. This update reviews scientific articles which might be useful to gardeners. Anyway, I just finished up a new edition earlier this week — which will probably be posted soon — that included one of the more interesting articles that I’ve seen recently. For my post today I thought I’d spend just a couple of paragraphs telling you about it. Unfortunately it’s not one that is readily available online, so I’ll give you the reference at the end of this article, but few of you will be able to see it without going to some effort.
So, what is this article about that has me so excited? Well, OK, excited might not be the word — amused might be a better word. So what is this article about that has me so amused? It’s about rubbing African violets with gloved hands or non-gloved hands treated with body lotion (Simply Basic Melon Delight Body Lotion). A researcher went to the trouble of rubbing these plants with their hands for 30 or 90 seconds at a time, 3 times a week, and then measuring plant response. And the results? Plants without any rubbing did best, followed by rubbing with a gloved hand, followed by rubbing with hand-lotion treated hands. And yes, 90 seconds of rubbing was worse than 30 seconds.
So, what does this research mean to you? Actually it probably has important implications for the African Violet industry and those who work in it, but to me it just reinforces the idea that plants are not pets…..
The Article: Brotton, J. C., and J. C. Cole. 2009. Brushing using a hand coated with body lotion or in a latex glove decreases African violet plant quality and size. HortTechnology 19:613-616.
Plant aficionados everywhere are constantly looking for something which they can patent and make a million bucks on — something like ‘Endless Summer’ hydrangea which captured the public’s attention — and their wallets. Many of the new plants we see today came from something called “branch sports” which are basically segments of a tree — like a branch — which has somehow mutated so that it offers something a little different than what the original tree did. If you’re familiar with ‘Delicious’ apples you may be interested to know that the ‘Delicious’ apples which you eat today are actually a branch sport of another ‘Delicious’ apple which wasn’t as attractive. Likewise, ‘Connell Red’ is actually a branch sport of ‘Fireside’ — they’re basically the same, but ‘Connell Red’ is considered more aesthetically attractive.
But some of those mutations are heart-breakers, Here’s an example.
This raspberry, which I found in my daughter’s raspberry dish last night (she was very upset that I stole it) has a really cool stripe running down it’s side. If someone found this in a raspberry patch they might be tempted to try to propagate the branch from which it came hoping to get striped fruit. Unfortunately that isn’t likely. This is an example of a sectorial chimera — where just a strip of tissue has been mutated. These types of mutations are notoriously difficult to propagate and so it’s unlikely that this mutation will last after propagating the branch from which this raspberry came. Still, it is kind of cool, isn’t it?
Recently there was an article published in the journal Science (widely considered one of the most prestigious science journals in the world) by two professors who I knew while I attended college in Pennsylvania (Franklin and Marshall College — Anyone ever heard of it?). I found this article particularly interesting because it explained how the beautiful Pennsylvania scenery that we assume is natural was actually created over the course of three hundred years. Saw mills and dams changed water flow patterns — those pretty streams that flow through the Southeastern PA (and nearby areas) that I grew up in aren’t natural at all.
Of course this is just another thing that we’ve done to make this country different from what it was when people first came here. We’ve also farmed the heck out of the land, built large industrial areas and, on top of that, there’s the issue of global warming (which, for the sake of this post, we’ll assume is caused by humans), increased carbon dioxide in the air, decreased top soil and forest land (mostly because of the farming), and a general increase in soil, water and air pollutants.
So, with all that said, It seems to me that we’ve done a lot of things to change the environment. With all that we’ve done why are we so upset when some plants, which we call “invasive” thrive in these settings? It’s not their fault that they do well in the conditions we’ve created. Sometimes I feel like we’ve built this great big smorgasbord of lutefisk (fish treated with lye — it’s pretty nasty) and then get angry when only people who grew up eating this type of fish come to the party.
I’m not trying to promote invasive plants — And I’ll be the first to admit that this post is oversimplifying the whole question of invasives — Still, it irks me sometimes that we aren’t more concerned about the environment where we plant our greenery rather than the plants themselves who, after all, are just feeding on the smorgasbord that we’ve created.
Linda sent me a link to This Comic the other day. Funny stuff — and not a little bit analagous to our friends who think that compost tea is the cats meow!
Here in Minnesota one of the things that we need to worry about is the cold. Over the winter we can see temperatures down into the -30s (even the -40s in the Northern part of the state) and it can damage many of the plants that we grow. The tops of the trees are usually able to handle these types of temperatures — though a good heavy snowfall can cause a limb to collapse now and again.
The bigger problem is with roots which aren’t able to handle the cold like the top of a plant can. Once you get 10 degrees or so below freezing you’ve killed the roots of most plants. Fortunately the ground is a great insulator and doesn’t get nearly as cold as you’d think. Once you get two or three inches under the surface of the soil temperatures will hover right around freezing for most of the winter. The plants that are most susceptible to cold are those that are in containers because their roots are above the soil’s surface. Nursery growers usually protect containers from the cold by consolidating them (pushing them together as in the picture below).
These containers are then covered with a layer of polyethylene fabric, about 6 inches of straw, and then another layer of polyethylene fabric. Temperatures under the fabric rarely go below 26 degrees or so — even when outside temperatures stay around -20. Most plants come out fine — our biggest problem is that sometimes voles and mice will take up residence under the tarp and eat the plants — which isn’t a big deal unless its a research project — in those cases we will often use poisons or, more frequently, repellents.
The only thing better than this method is snow. If we could count on snow every year we wouldn’t bother covering the plants at all. Snow is the best insulator that we have. Under snow temperatures rarely go below 29 degrees or so. So, despite the traffic problems that snow causes, nurserymen and landscapers are always happy to see snow on the ground before the really low temperatures hit.