Author: Linda Chalker-Scott

Dr. Linda Chalker-Scott has a Ph.D. in Horticulture from Oregon State University and is an ISA certified arborist and an ASCA consulting arborist. She is WSU’s Extension Urban Horticulturist and a Professor in the Department of Horticulture, and holds two affiliate associate professor positions at University of Washington. She conducts research in applied plant and soil sciences, publishing the results in scientific articles and university Extension fact sheets. Linda also is the award-winning author of five books: the horticultural myth-busting The Informed Gardener (2008) and The Informed Gardener Blooms Again (2010) from the University of Washington Press and Sustainable Landscapes and Gardens: Good Science – Practical Application (2009) from GFG Publishing, Inc., and How Plants Work: The Science Behind the Amazing Things Plants Do from Timber Press (2015). Her latest effort is an update of Art Kruckeberg’s Gardening with Native Plants of the Pacific Northwest from UW Press (2019). In 2018 Linda was featured in a video series – The Science of Gardening – produced by The Great Courses. She also is one of the Garden Professors – a group of academic colleagues who educate and entertain through their blog and Facebook pages. Linda’s contribution to gardeners was recognized in 2017 by the Association for Garden Communicators as the first recipient of their Cynthia Westcott Scientific Writing Award. "The Garden Professors" Facebook page - www.facebook.com/TheGardenProfessors "The Garden Professors" Facebook group - www.facebook.com/groups/GardenProfessors Books: http://www.sustainablelandscapesandgardens.com

Here’s the plant food everyone is talking about!

Apparently I don’t talk to the right people; I’d never heard of this product until newbie gardener and longtime skeptic John emailed me about Eleanor’s VF-11 plant food.

Upon visiting the website, this is what I learned about VF-11 and roses (the rose aficionado market is apparently a lucrative one for snake oil salesmen):

Point: “VF-11 Plant Food is not a ‘push’ like other fertilizers…think of it as a strength and health builder.”

Counterpoint: It certainly is not a fertilizer. It doesn’t contain enough minerals to do anything for a plant. So why not just use water? There’s something that can work miracles on drought-stressed plants!

Point: “VF-11 builds so much strength and health in your roses that plant cells ‘harden’ and ‘seal in the amino acids’.”

Counterpoint: I will kindly label this as nonsense since this is a G-rated blog. It says nothing but sounds sciency.

Point: “When you’re Foliar Feeding your roses, no need to worry if it blows back into your face. It’s gentle, gentle, gentle and safe.”

Counterpoint: Foliar feeding is an ineffective way of fertilizing plants (you can read more about in a column I wrote some time ago). In short, foliar application of specific nutrients is an excellent way of determining whether a deficiency of that nutrient exists, but it does nothing for the plant on a long-term basis.  I won’t beat that dead horse any longer. And thanks, I’d rather not have stuff blown in my face, regardless of what’s in it.

And more amazing facts elsewhere on the site:

Point: “And you do not need a lot of additives in your soil, like compost etc.”

Counterpoint: Wow. Who knew that organic matter was bad?

Point: “It’s an electrolyte balanced solution.”

Counterpoint: So’s urine. And urine has more nitrogen. (I won’t enter the debate about peeing on your plants.)

Evidence?

For evidence, the site offers two tissues analyses of pistachios that were sprayed with VF-11 (the foliar feeding method). The previous year (no VF-11) the leaves had high levels of copper and low levels of boron and magnesium. After treatment, the copper was reduced and boron and magnesium improved. Since boron and magnesium are not in the product, perhaps the copper was somehow transmuted into boron and magnesium? I can’t think of a more rational explanation if VF-11 is the causative agent. But I can think of lots of reasons this variation might happen from year to year, including the use of copper fungicides and the ability of some nutrients to restrict the uptake of others.

There’s also tissue analyses from a “sick vineyard” taken in June, then repeated in October after foliar application of VF-11. Both potassium and magnesium are singled out for note, though the ratings information is strangely missing (in other words, there’s no notation whether the levels are deficient, sufficient, or excessive). The differences between the %K and %Mg are circled for one sample, though a quick statistical analysis of all 4 samples show no significant differences between dates.  And even if there were – does anyone really expect leaf nutrient levels to be the same in June as in October? Keep in mind that the plant is both producing fruit and preparing for dormancy. Nutrients do move around!

Where did this magical recipe come from?

Again, relying on garden forums for my information (since the product website is vague on the topic), Eleanor “got the formula from a “cantankerous” elderly chemist who grew healthy plants, including tomato plants that were 30 ft. long.”

What’s actually in this miracle product?

According to the Washington State’s fertilizer product database (a really helpful resource for anyone, not just Washington residents), it is 0.15% N, 0.85% P, and 0.55% K (yes, these are all less than 1%). It also contains 3.5 ppm zinc and 3.2 ppm molybdenum. Products with such minute levels of minerals really aren’t fertilizer, but they really aren’t plant food either. Once this is diluted, you are left with…water. This is uncomfortably similar to homeopathic “cell salts,” which are highly diluted mineral products used to prevent disease in humans. Coincidentally, fans of Eleanor’s potions report that VF stands for Verticillium/Fusarium, “signifying that it creates disease resistance”. Hmm.

As Dr. Barrett points out on his QuackWatch site about homeopathic cell salts, “many are so diluted that they could not correct a mineral deficiency even if one were present.” I would venture the same would be true in plants. Again, Eleanor’s aficionados report that the “11” in the name “signifies it has eleven ingredients include iron, boron, copper, zinc, and molybdenum.” Hmm. Washington State’s analysis lab couldn’t find either iron or boron. Or whatever the other 4 minerals might be (besides the nitrogen, phosphorus, potassium, molybdenum and zinc).

Finally, the most bizarre use of this product must be the one reported by another fan of Eleanor’s: “Eleanor called me this evening and she could hear my parrots in the background…she told me that she, too, has birds. She then went on to explain that a woman told her that her birds looked terrible and that she started to spray them with Eleanor’s VF-11…an amazing improvement in both their plumage and in their attitudes…so, Eleanor did a test with hundreds of birds…and confirmed that spraying your birds often with the same mixture of VF-11 and water…room temperature…would enhance their feathering and make them much happier!

“Eleanor believes that indoor pets miss out on a lot of necessary nutrition due to being indoors….she stated the importance of animals and birds of being exposed to “dew”. I always assumed that dew was just water…but, Eleanor believes it contains nutrients.”

I think I need to stop now.

Morphology quiz answers

As Jason rightly guessed, this is a Schlumbergera species, specifically S. truncata, also known as the Thanksgiving cactus (which has toothed edges as shown). It’s related to the Christmas cactus (S. bridgesii – scalloped edges) and the Easter cactus (S. gaertneri, whose segments are three-sided rather than flattened). [Disclaimer: the nomenclature of this genus and its species is a mess. Even the university websites disagree on whether it’s Schlumbergera, Hatiora, or Rhipsalidopsis. Now you know why I am not a taxonomist.]

On to the more interesting question – those hairs. The green segments you see on these plants are not leaves, but flattened stems, called phylloclades (or cladodes). Phylloclade comes from the Latin word for leaf (phyllo-) and the Greek word for branch (-clade). These leaf-like branches are the primary photosynthetic organs for the plant.

So where, you may ask, are the leaves? That’s what those hairs are! And if you look at your Christmas/Easter/Thanksgiving cactus when it begins to set buds, you’ll see that the buds arise from the leaf axils – that point where the leaf joins the stem. This distinction is why these hairs are, morphologically, the true leaves of the plant.

How to get rid of your lawn

With increasing interest in reducing monocultural swaths of turf, summer water consumption, and the drudgery of mowing, many people are eliminating part or all of their lawns.  We did this at home some years ago and can attest to the tangible benefit of reduced water bills during our dry summer months.

The question I often get is – how? Do you dig up the turf and throw it out, then fill in with topsoil? Or do you cut it, flip it, and then plant on top of it? Or do you cover it up with cardboard to kill it?

We’ve tried all of these methods over the years (except sheet mulch, because you already know what I think about that).  What I now recommend is the easiest, cheapest, and most effective way to both remove turf and protect the soil. Here it is in four easy steps:

1) Mow your lawn as close to the ground as possible. Scalp it. If you can wait until it’s not actively growing (summer here in the west), that’s even better. Don’t water it!

2) Cover it up with – yes, you guessed it – a really thick layer of arborist wood chips.  They need to be at least 8″ thick and can be as much as 12-18″ deep without negative effects. They will settle quickly, so you do need to put enough down to maintain a 6-8″ depth after a few weeks. The depth is important to suppress the turf as well as any persistant weeds (like those you can see in the above photo).

3) Wait. Turf decomposition will depend on temperature and water availability – warm and moist conditions are optimal. After 2-4 weeks, pull part of the mulch back and check out what’s underneath. When it’s easy enough to dig through, then you can…

4) Plant. Be sure to move the mulch aside and plant into the soil. Replace the mulch to cover the disturbed soil and keep the weeds down. It only needs to be 3-4″ deep at this point.

It’s that easy.

Flower demystification

As Paul suspected, this is a Phalaenoposis flower.  Here it is again, shown next to another flower on the same plant (but different stalk):

  

As to the second question – why does it look this way – there could be a number of reasons.  I’m leaning toward environmental.  This particular flower stalk is an old one – after it had bloomed initially (with normal flowers), we left it on after the flowers fell.  As often happens, new flower buds appeared, but all of them have been abnormal.  Some were completely fused and never opened.  This one is missing most of its petals.

Other reasons could include viral infection (as Sheila suggested) or somaclonal variation (common in tissue cultured plants, which is how many orchids are propagated).  But this flower stalk is perpetually colder than the rest of the plant as it’s closest to the window.  And since its first crop of flowers were normal, I think this variation is due to cold temperature interference during flower development.

If you have other ideas, be sure to post them!

Permaculture – my final thoughts

We’ve had some good, vigorous discussion about permaculture, specifically around the book Gaia’s Garden.  I’ve pointed out some problems with the author’s understanding of relevant plant and soil sciences and will wrap up this week with a look at the glossary and bibliography.

Glossary

The glossary contains a number of scientific-sounding words and phrases with unscientific definitions; for example:

“Buffer plants: Plants placed between guilds or between allelopathic species. They should be compatible with the trees in each guild and should have a positive effect on one or both of the guilds to be linked.” (“Buffer plants” is a phrase legitimately used in ecological restoration where plantings separate wetlands or other natural areas from human activity.)

“Guild: A harmoniously interwoven group of plants and animals, often centered around one major species, that benefits humans while creating habitat.” (The term “guild” is ecological and refers to groups of species that exploit the same types of resources.  It has been hijacked and redefined for permaculture.)

“Narcissistic: Plants that thrive on the leaf litter of members of their own family, such as the Solanaceae, or nightshade family.” (In this case, this is an unscientific term given a scientific-sounding – but nonsensical – definition.)

“Polycultures: Dynamic, self-organizing plant communities composed of several to many species.” (Polyculture is an agricultural term referring to the planting of multiple crops. It’s a cultural strategy in Integrated Pest Management.)

“Sectors: Areas where outside energies such as wind, sun, fire and so forth enter a site. These energies can be mitigated, captured, or otherwise influenced by placement of elements in the design.”

Bibliography

There are only two books I would consider scientific; one soils textbook from 1996 and the other is Odum’s classic text Fundamentals of Ecology (1971). I’m disappointed in how scarce and dated these references are, given the wealth of more recent articles and books that are both relevant to urban gardens and scientifically sound.

The bibliography also includes many books on design and I’m not including them in this critique. Of those that remain, the bulk are nonscientific and in many cases pseudoscientific. Examples of the latter include The Albrecht Papers (Albrecht, 1996), Weeds and What They Tell (Pfeiffer, 1981).

And this last criticism embodies what permeates much of Gaia’s Garden: pseudoscience. In the glossary, we see scientific-sounding terms or definitions that are ultimately meaningless or incorrect. Furthermore, we see scientifically legitimate terms such as guild used incorrectly. Both of these practices are characteristics of a pseudoscience.

I think this is unfortunate. I’ve mentioned before that I agree with much of the philosophy behind permaculture. But dressing up this philosophy as science both misleads nonexperts and alienates scientists.

So here’s a challenge – why not write a new book on permaculture and collaborate with a scientist? (I know a few who are writers!)

Friday puzzler unearthed!

Lots of good guesses this week! As many of you realized, this is a huge tree root making the best of a small tree pit.  But it’s not a Norway maple (sorry John) or a mulberry (sorry Robert), but a sweetgum (Liquidambar styraciflua) (congratulations Brian!).  (You can see the little mace-like seed pods on the ground.)  The root does resemble a bicep (“Treebeard’s elbow”) flexing to crack the concrete (aka Robert’s  Concretious blandmulsia):

Though sweetgum can be nice urban trees, their roots are quite vigorous and can lift sidewalks several inches above grade as they increase in diameter:

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Thanks for all the entries – our readers are smart and funny!

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.