Yet another fine product

As a member of the GWA (Garden Writers Association), I routinely get emails about new garden products. Here’s one I received this week:

“I thought your readers or listeners might be interested in learning of a new way to protect their plants without using pesticides.  Moisturin, which contains no toxic ingredients, is sprayed on plants to form a clear flexible barrier strong enough to lock out both insects and airborne plant disease.  Moisturin is inexpensive, easy to use and extremely effective.  I would like to send you some at no charge for your own trial.  If your satisfied with it performance I hope you will pass it s benefits onto the people who trust your opinion.”

It turns out that Moisturin is simply a repackaged antitranspirant. Briefly, these spray-on barriers prevent water loss physically (by covering stomata) or physiologically (by closing stomata).  Interfering with stomatal function both reduces carbon dioxide uptake and water movement within the plant. You can read more about antitranspirants here.

But do antitranspirants have an effect on diseases or insects? Research indicates that while antitranspirants may reduce insect attack, their efficacy against diseases is less clear. They also show a clear negative impact on the plants they supposedly protect, to the extent they’ve even been tested as a form of weed control.

The best way to reduce pest and disease problems in garden and landscape plants is to keep them healthy. Reducing their ability to function normally by clogging their stomata will do exactly the opposite.

Building a Better Container, Part Deux: The Ellepot

I enjoyed Jeff’s post on the RootTrapper and thought I’d share another interesting and [relatively] new development in the world of greenhouse growing containers.

Take a tube full of growing media, wrap a paper sleeve around it, and voila – the Ellepot!

It’s bottomless, root permeable, and degradable. Each Ellepot sits in its own cell in a re-usable tray.  The great aeration and drainage makes for a happy, healthy root system.  Another plus is that after transplanting, there are no pots or packs to throw away

I’d say the bulk of Elle Pots are utilized at the propagation end of things – starting seeds and rooting vegetative cuttings – either for greenhouses  to “grow on” themselves or as plug/liner products sold to finishing growers (see student Paul Hutcheson holding a geranium liner above).

Ella and Ojvind Ellegard of Denmark developed the system in the early 1990’s.  Popular with growers in Europe, they’ve made their way to North America. Growers can buy in Ellepots by the pallet from various sources, or can invest in the equipment to make them

Wrap it up, I’ll take it…an Ellepot machine at Battlefield Farms, Rapidan, Virginia.

Sizes run from 15 mm (288 cells per 20” x 10” tray) up to 120 mm – equivalent to a  4” pot, perfect for bedding plants. Landscapers love them if they can find them – less waste from installation sites.

Petunia in an Ellepot. That’s Marc Verdel, head grower at Battlefield Farms.

As far as retail goes, I’m not sure if any market research has been done as to consumer preferences for this “pot-less” system. It’s a slight challenge for a shopper to pick one of this and two of that and transport them – you need some kind of carry tray. Anyone out there experienced with Ellepots (grower or gardener)?

Building a Better Container

As most of you know, roots circling around a container isn’t considered a good thing.  And so people try various things to control circling roots.  One of the more creative horticultural minds out there, Carl Whitcomb, a guy why basically got sick of academia and went into private industry (and, as far as I can tell, loathes peer review and the whole process of publication), decided to see what he could do about making containers that don’t encourage circling roots.  He came up with a number of designs, but my favorite is the RootTrapper.  The container is made of a flexible cloth which roots get lodged in, preventing them from circling.  Not that I’ve never seen a circling root in a RootTrapper, it’s just that these circling roots are extremely rare.

A row of elms in RootTrappers

A cut open RootTrapper

This is one of those innovative products that really works and it surprises me that so few people use this growing system.  Yes, it’s a bit more expensive than standard containers, and yes, it does take a little more effort to take the tree out of this container than a smooth sided one.  But man, I’ve never seen a better root system come out of a container than those which you get out of these.

Do These Come In Control Top?

For those color-conscious gardeners who can’t bear to have visible tomato ties (or panty lines):

Only $2.99 for eight pieces?  Whatta deal!

Do you know how many tomato ties you can get from a pair of hose? Especially if you are a “long”? About fifty. Of course they’ll be nude or black, unless you bought into that purple trend last season.


ps:   I do like Lusterleaf’s (company responsible for the above) can o’ twine with the handy cutter-top, though. $4 and it has lasted through several seasons.

Thieves purr

Today I found a cool website – it’s an anagram generator (  The title of today’s post is the first of the 553 anagrams generated from the word SUPERthrive.

I’ve been getting free samples of SUPERthrive for a long, long time.   For those of you living on a remote desert island, SUPERthrive is a product invented and sold by “Dr. John A. A. Thomson (in 27 different title Who’s Who Directories),” according to one of the promotional flyers.  The same flyer features Nick Federoff (“ ‘Most Listened-to’ Radio Garden Expert”), who says of Dr. Thomson “he has saved far more trees than anyone else in the world.”

Space constraints and my patience limit how many of the product claims I can include.  Here’s one from the package:  “Dozens of the world’s science miracles in each drop!”  Well, what are these science miracles?  The only identified compounds on the label are Vitamin B-1 (which plants make themselves, and which I’ve written about here), and NAA, an artificial auxin used as a rooting hormone.   The rest are mysteriously referred to as “crystalline compounds of C, H, O.”

Since this product has been around since 1940, there should be plenty of documented research on its efficacy.  But thorough searches of the plant science databases turned up only two:  one on growing hydroponic orchids (where SUPERthrive is used as part of the experimental protocol but not as a treatment) and one on rooting stem cuttings of Intsia bijuga, an Indo-Pacific tree in the pea family.  Sadly, SUPERthrive was not as effective in promoting rooting as were traditional rooting hormones (IBA and NAA).  An online research report from TAMU found SUPERthrive to have no effect on cotton.  Even California Science Fair participant Chingiz R. Bigalimov was disappointed that SUPERthrive did not enhance rooting of narcissus bulbs.

Why would Dr. Thomson, who “by 1979 had received a Ph.D in biochemistry and nutrition, and a Doctor of Arts in biochemistry and horticulture,” claim that SUPERthrive is a “billions-proven extra-life-maker” without the science to back this up?   I tried to find more information on Dr. Thomson’s doctoral research at Columbia Pacific University (an unaccredited distance learning school in California), but it had been closed by court order in 2000 for, among other things, failing to employ duly qualified faculty and failing to meet various requirements for issuing PhD degrees.

I think all of us GPs would agree that if you like a product and it causes no harm, more power to you.  But please consider these last few caveats, especially if you are a Master Gardener or garden professional:

  • There is no established science supporting the use of SUPERthrive;
  • NAA is an artificial rooting hormone classified by the EPA as a pesticide, making SUPERthrive an unregistered pesticide.  Some states ban the sale of this product.

Think I’ll go play with the anagram maker some more…


Just returned from a mega field trip across the state of Virginia with my Ornamental Plant Production & Marketing class. We toured major wholesale nurseries, greenhouses, and retail garden centers over the course of three days. The trip went well, I believe (university field trips are a considered a success if you return with the same number of students you left with).

One over-arching trend is, of course, that growers and retailers are going after the veg/fruit thing in a big way. Bonnie Plants has been one of the few vegetable transplant growers for the big box stores; now others are getting in on the act. Wholesale growers who traditionally supplied woodies and perennials to independent garden centers are including veg plants and herbs in their product mix.

Even the packaging is changing from the ubiquitous paper cup or poly 6-pack.  Coconut fiber (coir) pots are a step up from peat pots – they hold up better for the grower and garden center but are still plantable or compostable.


I can’t decide whether these pre-planted bean cages are ridiculous or genius. The students rated them “very cool”.  But how many beans can you get off of three plants?

bean thingies

Take some galvanized tomato cages, paint them bright colors, and charge three times the usual price. Who on earth would go for this? Oh wait, that would be me. Two. In orange. Cram ’em in the van, people.

I must have eet

Another fine product…

I’m spending this week in Palm Desert, CA for a little R&R in the sun.  In the morning, with my pot o’ Earl Grey, I read the local paper (The Desert Sun).  Last Sunday’s paper provided me with an article about an “intelligent water incubator” (all material in quotes was taken from the article).  Pieter Hoff, a “Dutch scientist, author, and major exporter of lilies and flower bulbs” has invented the Waterboxx, which “produces and captures water from the air through condensation and rain.”  He claims a four year test in the Moroccan Saharan desert showed an 88% survival rate for fruit tree saplings “grown without irrigation.” He now wants to test his invention in the Coachella Valley desert “to create a money-making business model with trees” and of course to help save the environment.

The Waterboxx is a plastic rectangular box, but we’re told the inner technology is more complex.  The box is put around the seed or sapling and provides water “in small doses.”  It also “protects roots against sun, wind, weeds, rodents and some animals.”

I visited the web page and you should too.  The technology section is fascinating.  It includes an animation explaining how the box functions; apparently the box was designed to protect seeds in the same manner as bird poop.  I was interested to see that the box requires 4 gallons of water when it’s set up; not exactly a “no irrigation” methodology.  And that a wick inside the box releases about 50 ml of water a day to the soil below the box.  The last frame tells us “with the waterboxx we can transform most of the deserts into forests.”

I won’t test your patience by dissecting all the silliness in this article and the web site.  As you might expect, there is no peer-reviewed science on this product, nor even a research report.  The plant and soil science is marginal; the ecological science is horrific.  The box effectively prevents water from reaching the soil around the seedling, doling it out in miniscule doses instead.  Not only could a decent organic mulch layer do the same job (and do it better), but I question the “greenness” of creating yet another plastic product with a limited lifespan.   This system is so removed from reality that it’s incredible that anyone takes it seriously – yet it’s been out there for several years now and has won several awards.

Oddly, there’s little specific information about the inventor.   All I could find definitively is that he comes from a bulb-raising family in The Netherlands and has written a book:  CO2 – a gift from heaven (under the name Petrus Hoff).

You say tomato, I say phytochrome

Yesterday I got an interesting email about a new product – a Tomato Automator.  Briefly, this square, red plastic disk slips around the stem of a tomato plant to suppress weeds and pests.  Most intriguingly, we’re told that the color “triggers a natural plant protein that makes tomatoes mature faster and product more fruit.”

Given this is a red product, it’s likely that the protein referred to is phytochrome (literally, “plant pigment”).  Phytochrome activity is maddeningly complicated to explain, so we’re going to keep this simple and refer (somewhat inaccurately) to “active” and “inactive” forms of phytochrome.  The active form of phytochrome exists when red light is predominant and encourages leaf expansion, chlorophyll development, and other characteristic of plants growing in full sun.  In contrast, the inactive form of phytochrome occurs when red light is reduced, either at night (when there’s no light) or in shaded conditions, where far-red light is predominant.  (Far-red light occurs just outside our range of visual perception but is absorbed by phytochrome.)

From a practical standpoint, this means a plant can “tell” whether or not its light environment is limited: both red and blue light are absorbed by chlorophyll, so a low level of red light means poor photosynthetic conditions.  Under such conditions, “inactive” phytochrome causes many plants to become etiolated (have abnormally long stems) in an attempt to outgrow the shade before it starves from lack of carbohydrate production.  In addition, this photosynthetically-poor light environment can also increase fruit set by redirecting resources to seed production rather than foliage  – perhaps a plant’s last effort to reproduce before it dies.

OK, now onto the useful application of this information.  Several years ago researchers investigated that effect of different colored plastic mulches on tomato production.  Again, to keep this simple we’ll just focus on the effect of red mulches.  It’s pretty much agreed that red plastic mulch reflects both red and far-red light, increasing not only red light but paradoxically the relative levels of far-red light.  Theoretically, this shift would cause tomatoes to put more resources into fruit production, and indeed some studies found this to be the case.

Unfortunately, the phenomenon is not consistent throughout repeated field studies.  Some of the other confounding factors are soil temperature (warmer temperature = more growth), insect and disease pressure (both decrease tomato production and are variably influenced by mulch color), and the fact that ethylene production (the plant growth regulator responsible for fruit ripening) is not controlled by phytochrome at all.

So are Tomato Automators worth the trouble?  Probably not, especially if you have many plants requiring many automators.

Packing Pearls

Yes, not my day to post, but I just received an email with a link to a new product called Packing Pearls.  These are polystyrene balls that fill the bottom of large containers so they aren’t so heavy.  They are promoted as “improving water drainage and oxygen flow.”  You can find a link here

The “pearls” are separated from the soil and plant roots with a pot liner (composition unknown).  We’re told that the roots can’t grow through the pot liner.  So now my question:  can a material that “improves water drainage and oxygen flow” be impervious to root growth?  Doesn’t it sound as though you’d be waterlogging the soil by installing this liner?

I honestly don’t know the answers to these questions, and the web site is not detailed (nor does it contain any links to research).  The emailed advertisement states “Tests show that flowering plants bloom two to three months longer when grown in containers with a base of Packing Pearls. Plants are also visibly healthier and hardier.”

Anyone used this system before?

Checking up on FreezePruf

As winter continues to hold its icy grip over the middle of the country, our thoughts don’t stray too far from plants and cold.  Recently one of the graduate students in our department, Nick Pershey, brought to my attention a new product called FreezePruf that claims to improve plant cold hardiness by up to 9 degrees F.  Since a couple of degrees of improved cold tolerance can be a big deal (just ask a Florida citrus grower after a 29 deg. F night), nine degrees F. is huge.  At first blush, FreezePruf looks ripe for the Garden Professors’ picking.  The promotional claims are sensational and are followed by the obligatory exclamation points.  “Just spray it on.  It’s like moving your temperature zone 200 miles south!”  So the obvious questions are: What is it? What does it do?  Does it work?

What is it? FreezePruf is a mixture of several fairly common compounds.  These include WiltPruf (a film-forming anti-transpirant), SilWet (a surfactant – helps material spread and stick to leaves), AgSil (potassium silicate), polyethylene glycol (an osmoticum – PEG is widely used in cosmetics and laxatives), and glycerol.

What does it do?  To understand what FreezePruf does it’s helpful to understand how freezing injury occurs in plants and how plants tolerate freezing.  First, remember that water exists in plant tissues between plant cells (extracellular) and within cells (intracellular).  When plants are exposed to freezing temperatures ice forms first between cells (extracellular ice) but not within the cells.   This is due to the fact that water within cells contains solutes that depress the freezing point.  Freeze damage can occur in a couple ways.  One is ice formation within cells (intracellular ice).  Tissues can also be damaged if cells become excessively dehydrated as a result of extracellular ice formation – the ice between cells acts like a salt or osmoticum to continue to draw water of the cell and into the intercellular spaces.  The formulation of FreezePruf apparently acts to depress the freezing point within the cells (due to potassium ions and PEG) and to limit cell dehydration.

Does it work?  At present the only data available on FreezePruf is from the product developers in their patent application.  To date, nothing on the product has been published based on peer-reviewed studies; which always makes the Garden Professors skeptical.  The product development team, however, is lead by Dr. David Francko, a plant biologist and Dean of the Graduate School at the University of Alabama.  Data in the patent application show improved cold hardiness on the order of about 4-5 deg. F for a variety of cold sensitive plants, mostly palms, bananas and annuals.  In some cases the protection was only a couple of degrees but in one case ranged up to 9 deg. F.

What’s the bottom line? For most gardeners the principle benefit of FreezePruf would be to protect plants from the first few early frosts in the fall.  The question is whether you’d rather spray a relatively untested product versus relying on tried and true methods (e.g., bringing container planters in, covering sensitive plants with old bedsheets).  The developers claim FreezePruf can last up to 6 weeks – that could save a lot of dragging bedsheets around the yard.

Caveats: FreezePruf is marketed as ‘Eco-Safe’  – whatever that means – although the MSDS sheets of some of the component products indicate eye and skin irritation are possible.  Until a longer-term database is available I would be cautious of unintended results.   For example, could this stuff make plants more attractive to pets or wildlife?  We’ve seen reduced cold hardiness in conifers using WiltPruf alone, it would be interesting to see some data on Freeze-Pruf on conifers before recommending it for use on those.