The New Evidence Against Glyphosate

This past week Susan over at Garden Rant asked me about a paper which she had recently read which “proved” that Round-up caused birth defects.  This study was interesting because it took embryos of chickens, exposed them to glyphosate (the active ingredient in Round-up) and then looked at the problems which the embryos had.  Indeed, there were problems at concentrations of glyphosate much lower than what you’d see in normal agricultural applications.  This is similar to other studies which “prove” how toxic glyphosate is which have been conducted over the years where various types of cells have been removed from human bodies, exposed to glyphosate, and then the resulting cellular damage has been taken as an indication that this herbicide is incredibly dangerous to us.

Studies where embryos or cells removed from the human body are tested against poisons have a glaring weakness which needs to be appreciated before we go off the deep end thinking that they prove that glyphosate is killing us.  They’re conducted in a system that isn’t at all natural.  That’s not to say they have no importance, but it’s like saying that, because it’s known that an air bubble in your bloodstream will kill you, air is dangerous.  Or like saying that, because salt injected into your bloodstream is deadly, you shouldn’t eat it.  Both air and salt can be deadly if they are in your bloodstream above a certain level, but we need to be careful to look at the specific situation with which we are dealing and take that into account when we make our judgments about how toxic particular things are to us.

I can’t argue that glyphosate can be toxic to people.  This morning I did a little literature search on it and actually found cases where people had committed suicide by drinking agricultural formulation of glyphosate  – mostly in the Eastern world.  It would be a nasty way to go too – you’d need to ingest a lot of the stuff and the primary problems would be that parts of your gastrointestinal system would be corroded.  Ouch!

If you’re going to use a glyphosate herbicide use it carefully and in accordance with its label.  Don’t go splashing it around willy-nilly.  Don’t drink it.  Don’t get it on anyone.  Don’t use more than you need to.  To do any of these things is not only dangerous, it’s also stupid.  That said, I can’t find any reason to think that glyphosate is anything but what it appears to be – an effective weed killer that is on the safer end of the spectrum relative to other chemical weed killers (and here I’m including organic weed killers too – Ever been exposed to those 20% acetic acid vinegar herbicides?  I tried one this summer — Just being near it made my eyes burn.)

Off with their heads!

About a year ago I posted my thoughts about the nursery production practice of heading young trees (“whips”) to stimulate lateral branching or columnar form or whatever.  (You can find this original column here.)  A healthy discussion ensued, much of which revolved around the need for appropriate follow-up pruning to ensure the development of a stable crown structure of headed trees.

Fast forward to last month, where a column I wrote for NPM (Nursery Production and Management) magazine hit the web.  And then the fan.

I made some people very unhappy with this article.  I had a lengthy and productive conversation with one such person last week, during which we agreed on many things, including (1) trees that are headed develop multiple leaders; (2) multiple leaders, however they’re created, need to be thinned to one central leader; and (3) uncontrolled multiple leaders can create hazardous conditions.  The bottom line, from a nursery production perspective, is that headed trees require regular pruning to create and maintain natural, structurally sound crowns.

And here’s my problem:  how many homeowners are going to perform this regular pruning?  Furthermore, how many homeowners KNOW how to perform corrective pruning?  We all know that number is going to be abysmally small.  Even for those situations where competent arborists could do this regular pruning, how many communities budget for this activity?

More troubling for me as a scientist is the lack of peer-reviewed scientific papers on this practice.  Though there are numerous papers documenting the effects of pruning, I can’t find any that specifically look at the long-term effect of heading trees during nursery production. You’ve heard all of us GP’s say it before – unless you can show us the data in a published and peer-reviewed format, we can’t regard anecdotes as anything but.

The nursery industry has invested a lot of time and money in a practice that leads to problems for which no one will claim responsibility.  Production nurseries wash their hands of the issue once the trees leave their facility.  Many retail nurseries don’t perform the necessary follow up pruning while the trees are in their care (do any retail nurseries do this?  Are they aware of the problem?).  Homeowners don’t receive information or training on how or why to perform corrective pruning.

What I’d really like to see the nursery production industry focus on is consumer education.  The metamorphosis of a sapling into a maturing tree is a wondrous thing.  Rather than interfere with the process, we need to cultivate patience as well as a respect for tree physiology.

Animal, Vegetable, Irritable

I’m a big Barbara Kingsolver fan. Just finished “Prodigal Summer” – her tall, lanky, introverted, 40-something forest ranger-heroine encounters handsome, mysterious, much younger guy in the woods; sparks fly, etc.  Rowr!  Ahem.

I really enjoyed “Animal, Vegetable, Miracle” when it came out a couple of years ago. It was the perfect dead-of-winter read as she captured flawlessly the itch to grow things, the scent of thawing soil, the joys of mud, the overwhelming greenness of spring, the mess of canning tomatoes. I was only slightly annoyed at the quiet pace and perfectness of her home life;  as a normal working stiff I don’t have time to bake my own bread daily, or make fresh mozzarella every time we have pizza for dinner (darn this time-consuming, bill-paying job).

But I was totally mesmerized by the cover art – her daughter’s cupped hands filled with the most beautiful shelled beans in the world. The huge maroon and white Christmas Limas shined like leguminous jewels.  Now THAT I can do.

So, Dr. Miss Smartypants here devoted an entire row to them this spring – about twenty feet with plants spaced on one-foot centers and a 20’ x 6’ span of netting for them to scramble up. The second 20’ row was planted with red and green yard-long beans (see my previous post about how fabulous they are).   Both rows received the same amount of irrigation (a little), weeding (some), and zero additional fertilizer except the pre-plant amendment of chicken poop (of which we have a lot).  

Summer wore on, life got busier. The yard-long beans just kept coming despite drought, stinkbugs and 3’ tall lambsquarters.  I’d poke around wistfully in the Christmas Lima vines – there were a few green pods buried amongst copious foliage. I do know these kinds of beans do better in hotter, drier climates, but it’s been pretty much that kind of summer here.

The pods finally, FINALLY filled out a bit and turned dry and brown – ready to pick!! I filled most of a five-gallon bucket and sat down with a beer to shell them (OSHA requirement).  

Behold, my bounty!

 

Total yield: one mess of beans. Two if used as soup components. Yes, they’re listed with Slow Food USA’s Ark of Taste.  Yes, they are indeed beautiful and will probably be totally delicious whenever I get the nerve up to cook them.

It’s just… I’m not sure how to put this… but a family of four would BLOODY WELL STARVE if they devoted much of their garden to these lovelies. I don’t know whether to eat them, frame them, or string them onto a necklace.

p.s. still getting yard-longs by the handful…

Maybe the handful was all Barbara got, too

Turf trickery

Now I feel a little guilty.  You tried to answer Friday’s puzzle so seriously, and I was taking liberties with photography:

I think this is the coolest garden stairway I’ve seen yet.  The buffalgrass tolerates moderate foot traffic, and it lends a fluid look to the otherwise hard edges of the steps.  And you can’t tell from looking, but it both felt and sounded silky.  Best of all, it doesn’t require mowing.  (This is the Rolston/Cohn garden, part of the garden tour put on by the GWA in Dallas last week.)

How to Kill Buckthorn

Last year we completed a small research study on how to kill buckthorn.  If you live in the upper Midwest then you’re familiar with this plant as a shrub which has escaped cultivation, been spread by birds, and generally made a nuisance of itself, particularly at the edges of forested land.

Buckthorn is notoriously difficult to kill after it gets more than about a foot high.  It laughs at single applications of roundup. If it’s pulled out of the ground any roots that don’t come with it have a good chance of sprouting shoots themselves, and it seems to enjoy being treated with organic herbicides like vinegar.  So, to try and kill bucktorn, we used an herbicide which had the active ingredient triclopyr.  This is an active ingredient which is usually great against all manner of weedy vines like poison ivy.  This herbicide is labeled for homeowner use and is available in most garden centers.

We applied this herbicide to buckthorn in the spring, summer and fall, and we used a few different application methods including painting the herbicide onto cut stumps and spraying it onto the leaves of uncut bushes, as well as painting the product onto the lower portion of stems.  Some of these application methods were experimental.  Do not attempt to apply an herbicide in any way besides that which is listed on the label!

That said, we found that the fall was by far the best time to apply the herbicide and that spraying the foliage wasn’t nearly as effective as other application methods, particularly painting the cut stem with the product after cutting it down.

Sheet mulching – benefit or barrier?

Alert reader Matt Wood pointed out a recent article in the NY Times on mulching with newspaper and wondered about my take on the topic.

For use on landscapes, I do not like sheet mulches of any stripe.  They tend to hinder to air and water movement, most especially in unmanaged landscapes like restoration sites.  A classic example is the use of cardboard or newspaper covered with wood chips.  The chips are easily dislodged, exposing the sheet mulch which quickly dries out and becomes hydrophobic.  Thus, the roots of desirable trees and shrubs lose out on the water, while the weeds surrounding the edges of the mulch benefit from the runoff:

Published research on sheet mulching in landscape settings confirms the drawbacks of sheet mulching.  But the article in the NY Times is about vegetable gardens.  This is a different situation – more akin to agricultural production than to landscape horticulture.  Vegetable gardens are routinely managed during planting, thinning, weeding, and harvesting.  Newspaper sheet mulches in these situations rarely dry out and, when kept buried and moist, do break down quickly.

So – keep the sheets on the (vegetable garden) bed where they belong!

It’s a Bird! It’s a Plane! It’s a …Butt?

So we last left off discussing the issue regarding the fact that the point is incumbent on us that one can’t refer to a native as "invasive" withou…

Look!

What’s that??!
There! Amongst the Pachysandra!

Is it a freshman? Perhaps passed out in our campus garden in despair after yet another stinging defeat of the Hokies?

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Nay, ’tis a pair of Calvatia gigantia – Giant Puffballs.

'Tis not a butt

Pretty impressive, though. Note toes for scale. Unfortunately, with all the foot traffic in our garden, there’s little chance they will make it intact to the "fun stage" (official mycological term for when the exterior turns dark ‘n crispy and the internal spores floof out in huge clouds upon poking).

I fully expect our Pacific Northwest people to be all "You should see the size of OUR Calvatia species!"
Bring it.

Another W.O.W.

We’ve been beating up nurseries over Why-Oh-Why (W.O.W) do they sell things like Scot broom.  Here’s one of my  favorite W.O.W’s from the landscape side (Homeowner division).

Why-oh-Why do people think grass clippings make a good mulch?!  This photo comes from near my home.  The homeowner put the clippings down about two months ago.  All the trees were dark green and healthy before the clippings were put down.  Note how chlorotic the trees in the middle have already become and the dead lower limbs where the trunks were covered.   We’re all for mulch but this ain’t it!

A freakin’ violet

Friday’s puzzle scared you off!  Matt was correct – this is an African violet (Saintpaulia spp.).  But unlike other African violets, this one never opens its flower buds (Sandy nailed it!).  Originally cultivated in Germany, these plants are marketed in the US by Optimara Violets.  That’s all I can tell you about this quirky little cultivar.