Last Sunday Jeff Gillman and I were guests on Mike Nowak’s Chicago-based gardening show. It’s now linked up, so check it out if you feel so inclined!
There’s been discussion on Facebook as well, primarily about (you guessed it) compost tea. (You’ll need to find the #gardenchat group and scroll down to Mike’s posting to see the lively discussion.)
Last time I posted I began discussing this link about horticultural molasses. Let’s continue with the dissection:
“When molasses is sprayed directly on plants, it is absorbed straight into the plant. Once absorbed, the sugar content of the plant goes up. If you need proof, go pour a Coke on a spot in your lawn, in a week you will see exactly what I mean. Simple sugars are how plants store energy for rainy days and winter hibernation. So, why is this important to you as a gardener? Aside from basically giving your plants a power boost, you are stopping bugs. “What?” you ask. Yes, it stops bugs. Insects are very simple creatures. They can only feed within a narrow window of sugar content. When the sugar content of plants is raised, insects can’t feed on them. They take one bite and move on.
“The second way molasses controls insects, is by being directly ingested by the insect. What most people don’t know is that only Sugar Ants and bees can process the simplest sugars. Insects have no way of expelling the gas that builds up from fermenting sugar and the vegetation in their gut (draw your own mental pictures please). Plus, they have exoskeletons and can’t get bloated. Their delicate internal organs are crushed from the inside out. All a bug needs to do, is walk through or try to feed on a molasses covered plant. Insects are constantly cleaning themselves. They will try to lick the molasses off their feet and swallow it. If they take a bite of a molasses coated plant, they will swallow it.”
Some specific observations and comments:
1) “If you need proof, go pour a Coke on a spot in your lawn, in a week you will see exactly what I mean.” I just don’t think I can do this comment justice, so I’ll leave it to your imagination as to what you might see and how it relates to a 1% molasses solution sprayed onto leaves.
2) “Simple sugars are how plants store energy for rainy days and winter hibernation.” Actually, no. Simple sugars are difficult to store as they contain a lot of water and they can be quite reactive. Plants transform simple sugars (monosaccharides and disaccharides) into polysaccharides for storage.
3) “Insects are very simple creatures. They can only feed within a narrow window of sugar content. When the sugar content of plants is raised, insects can’t feed on them. They take one bite and move on.” Obviously the author has never seen Men In Black.
Give me sugar…in water
4) “What most people don’t know is that only Sugar Ants and bees can process the simplest sugars.” Please explain this to the cockroach I once saw in a sugar bowl.
5) “Insects have no way of expelling the gas that builds up from fermenting sugar and the vegetation in their gut. Their delicate internal organs are crushed from the inside out.” Did you know that termites are significant producers of methane gas – a byproduct of fermentation? And they release it the old-fashioned way.
From NASA’s website on methane production
More next week!
Yesterday I received this link from a Facebook friend who said “when I read this I thought of you.” More likely she was thinking of (enjoying?) the mental agony I suffered as I waded through this morass of misinformation. (By the way – those of you who are educators of some sort – this would make a great “how many things are wrong?” question for your students.)
There’s SO much to discuss in this post that I think I’ll split it up into separate posts. Here’s the first paragraph:
“Cheap, easy and does it all!
“Not your kitchen molasses! That has had the sulfur removed and you need it in there. Horticulture Molasses does things for your plants like nothing else can and it’s the cheapest gardening product per square foot…a gallon can cover a half-acre! Put it in a sprayer, turn some music on and start spraying every inch of your yard, no need to be careful. You simply can’t over do it. Molasses raises the sugar content of plants and kills insects,causes a massive bloom of microbes in the soil and drives out Fire Ants, what more do you need?”
I’d not heard of “horticulture molasses” before, but there are so many new products sneaking into garden centers that I’m not too surprised. Let’s look at some specifics here.
A while back I wrote about a Seattle-area neighbor dispute over a tree partially blocking their view. Sadly, the tree lost out in this case, which was decided a few weeks ago.
Now a second tree vs. view dispute was reported this week. You’ll have to read the story to see how many things are inaccurate/indefensible/infuriating about the “trimming” of this 90 foot western red cedar (a native species). My personal favorite: “the tree violated neighborhood bylaws ensuring no house’s view would be blocked.”
I wonder how they got the tree to agree to the bylaws in the first place?
Last week dedicated blog follower Ray E. sent me this link to a story in the Smithsonian magazine. It’s a fascinating look at adaptive responses by frog eggs and apparently is causing quite a stir in the evolutionary biology community. Phenotypic plasticity, which is the ability of an organism to modify its appearance or behavior based on environmental cues, is being hailed as a “revolutionary concept in biology.”
I don’t get it.
Anyone who’s studied plants for any length of time knows about this phenomenon. It’s why plants grow taller in the shade than they do in the sun. It’s why leaves inside a tree’s canopy are larger and thinner than those on the outer layer. In fact, it’s that darn phenotypic plasticity that can make data collection so difficult for those of us who do field research. Minimal differences in wind, water, soil chemistry, etc. in a research plot (or a garden, for that matter) are magnified once plants start responding to them.
This leads to one of my pet peeves about the state of biological research over the last few decades. If you look at the research that gets the big grant dollars, it’s either at the smallest scale (like molecular genetics) or the largest (like systems ecology). Those of us who are fascinated with how organisms work are pretty much left to our own devices to fund research. (The exceptions to this rules to a certain extent are human and veterinary medicine.)
While this may seem abstract to most of you, the funding imbalance filters down into the teaching function of colleges and universities. When I was doing my undergraduate and graduate degrees, my university had a bryologist (someone who studies mosses), an algologist (marine and freshwater algae), a botanist who specialized in diatoms, and so on. Most major universities had a reasonable number of faculty with expertise over distinct groups of organisms.
As these faculty retired, they were replaced by new faculty whose value was measured more by potential grant dollars than by replacing the loss of expertise. Thus, we have fewer entomologists or mycologists or even horticulturists, as universities scramble for the federal dollars (and substantial overhead) needed to support their institutions and obtainable by a small and select group of researchers. And university curricula reflect this shift, with the disappearance of distinct programs in botany and horticulture and plant pathology and weed science and crop science, as they are mishmashed into bland and unappealing “plant science” departments. Or worse, simply “biological sciences.”
So it’s no great surprise, I guess, that many evolutionary biologists are amazed at the “revolutionary concept” of phenotypic plasticity. I’m not sure many students – or their professors – spend as much time looking at and learning from organisms as they used to.
Bert’s post yesterday inspired me to share one of my own timelines that I followed for 7 years. As many of you know, I am a proponent of bare-rooting container and B&B shrubs and trees. One of the benefits is that you can prune away malformed roots, but another is that you can ensure the roots come into contact with the native soil as soon as possible. It’s interesting to see what happens over time with the more typical “pop and drop” method.
I saw this rhododendron being planted in 2002. If you look closely, you can see that it was originally balled and burlapped – the burlap is up around the multiple trunks. Then the burlapped bag was put inside a contained filled with media. You can see that, too. So a hole was dug that exactly mirrored the plastic container and the whole works was lifted out and plugged in.
Visualize a giant jawbreaker with different colored layers. At the center, we have the roots surrounded by clay. This is encased in burlap and twine. Then there’s a layer of container media. And finally we have the native soil. Rather than making it easy for this rhododendron to get established, we now have several barriers for new roots to overcome.
The primary problem here is all of the different textures of stuff in this planting hole: clay, soilless media, and native soil. Water doesn’t move easily through different soil types (remember Jeff’s demo on drainage?) and if water doesn’t move, neither will the roots. And as you follow this time line, it becomes quite apparent that the roots never established into the native soil. Look in particular at the size of the leaves (they are markedly smaller as time goes on – a great indicator of chronic drought stress). The line in the masonry wall makes it easy to see changes in height – or lack thereof.
Last Sunday’s New York Times had a story about immortal jellyfish. It was interesting, and given my previous life as a marine biologist, it was also a topic that was comfortably familiar. But really, I wasn’t that impressed. Because plants do the same thing, yet no one bats an eye.
Gardeners and other plant aficionados have exploited the plant kingdom’s ability to remain forever young. How many of us have taken cuttings of mature plants, rooted them, and started new ones? I have a couple of miniature African violets whose leaves I can place on damp soil in pots, cover, and ignore. New plantlets emerge from the base within a few weeks. I pot these up and give them away as gifts, but always keep a few for later propagation.
Some of the horticultural oddities we love exist because of plant immortality. The Camperdown elm (Ulmus glabra ‘Camperdownii’) has been perpetuated for almost 200 years from a single original cutting from a tree in Scotland. Particularly pernicious weeds do this on their own thanks to runners and rhizomes. Sure, we call it “vegetative propagation,” but really, it’s plant immortality.
So you’ll have to forgive me for not getting all torqued about immortal jellyfish. I’ve seen immortality, and it’s growing in my garden.
In deference to the holiday season, I’ll step down temporarily from my soapbox and mention a great holiday gift idea for your favorite gardener.
I saw this sedum stump a few years ago when I was speaking to a Master Gardener group in British Columbia. The porous nature of the stump would make it easy for the roots of the sedums and other rock-garden types of plants to establish. And the stump could be easily moved to wherever the recipient desired.
This isn’t just a warm climate idea, either. There are a number of sedum species that are cold hardy and as long as the stump was well protected in the winter, the roots would be fine.
Today I received my November 2012 issue of Arboriculture and Urban Forestry. This is one of the few peer-reviewed journals that generally has information of immediate value to gardeners and landscape professionals as well as academics. This issue contains an article entitled “Evaluation of biostimulants to control Guignardia leaf blotch (Guignardia aesculi) of horsechestnut and black spot (Diplocarpon rosae) of roses.” (And before you ask, no, I can’t attach the article or link to it. You’ll need to read it in the journal itself or wait for a year when the organization makes it available to everyone.)
Anyway, this study looked at eight different self-identified biostimulants, including Superthirve (which every gardener must have heard of by now). In addition to Superthrive, the other products tested were Maxicrop Original, Resistim, Bioplex, Fulcrum CRV, Redicrop, Crop Set, and Systhane. Purported active ingredients within this group include seaweed extract, molasses, vitamin B, and Lactobacillus fermentation product.
And the $64,000 question – did they work? Here’s the authors’ summary: “Irrespective of pathogen or concentration applied, none of the biostimulants used in this investigation provided a significant degree of Guignardia leaf blotch or black spot control compared to water-treated controls.” In other words, you can expect the same results by spraying your black spot-infested roses with water compared to any of these biostimulant products.
The authors end their article with a caveat sure to warm the cockles of every Garden Professor’s heart: “Results of this study indicate that where independent scientific data are not available to support the pathogen control claims of the manufacturer, then using an unevaluated biostimulant for this purpose is not recommended.”
(I’m glad this article is finally out. I was one of the peer reviewers for it, and I’ve been wanting to share the results on the blog ever since I read it.)
There’s a new report out from the Weed Science Society of America (WSSA) which blasts a common piece of gardening advice: use least toxic pesticides only as a last resort. Popular as it may be, this advice is not scientifically grounded and can actually cause more harm than good. The WSSA is joined in this announcement by the American Phytopathological Society (APS) and the Plant-Insect Ecosystems Section of the Entomological Society of
America (P-IE ESA).
This is a must-read for anyone who is a responsible educator regarding pesticide use, which includes Master Gardeners and other horticulture paraprofessionals. You’ll want to use the webpage link above to read the entire announcement, but here’s a paragraph to get you thinking:
“There is no benefit or scientific basis to simplistic messages like “use least toxic pesticides as a last resort” for the large number of pesticide users who apply pesticides according to the label and practice good stewardship. Nor are these messages beneficial for those who neither seek training nor adequately read the label believing instead that it is safe, practical, and effective to simply choose a product considered a “least toxic pesticide” and apply it only as a “last resort.” These messages hinder pesticide safety and stewardship education and practices that are in the best interest of the pesticide user, our food supply, public health and ecosystem preservation.”