Amusing Facts – Page 13 – The Garden Professors™

Is Petting Your African Violet a Good Idea?

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.

Better Red than Dead!!!

David, one of our newer readers, asked why his red-stemmed roses seem to be more cold hardy than the green-stemmed cultivars. So today’s blog will be dedicated to a brief discussion of why it’s better to be red than dead.

The brilliant red, blue, and purple colors seen in flowers and fruits are due to anthocyanins (and the closely related betacyanins). These water-soluble, non-photosynthetic pigments are also commonly found in stems, leaves and other vegetative tissues. In 1999 I wrote a review article exploring the reasons that leaves and stems might turn red. A few years later I wrote another review, more specifically looking at how anthocyanins might influence plant water relations. (This last phrase is plant physiology-geek jargon, and I have to admit that the class I took on this topic during my PhD work was the hardest, and probably most hated, of all the classes I took. And now it’s turned out to be one of the most valuable. Go figure.)

While you hard-core types can read the review articles that I’ve hot-linked above, what I’ll try to do is summarize my hypothesis for why leaves (and stems) turn red. Some leaves are red when young, then turn green when older. Green, deciduous leaves turn red before they fall off in the autumn. And some plants are genetically programmed to have red leaves all their lives.

The environment can also influence leaf reddening. Drought, nutrient deficiency or toxicity, salts, heavy metals in soils, cold temperatures, low soil oxygen, whew! All of these environmental factors have been attributed to temporary reddening. What do these factors have in common?

It turns out that all of these environmental stresses directly or indirectly affect the ability of plants to take up and/or retain water. Because anthocyanins are water-soluble, they effectively dilute the concentration of water in the plant. Look at it this way: any limited area will only hold so many water molecules. A test tube of pure water has the maximum number of water molecules possible. A test tube of water plus sugar (or salt, or anthocyanins for that matter) will have fewer water molecules, because the other substances take up space, too. So effectively, anthocyanins reduced the apparent concentration of water in plant tissues.

Why is this important? Well, anthocyanins in leaves helps reduce water loss, because the concentration of water in the leaves is reduced and evaporation slows down. They also could serve as antifreeze compounds, allowing red leaves (and stems, David!) to be more cold hardy. And if anthocyanins aren’t amazing enough already, they also (1) bind and transport sugars during fall leaf color change, (2) protect tissues against high levels of solar radiation, and (3) are natural antioxidants. (That’s why you’re supposed to eat red fruits!)

I could go on and on, but I hope this might help explain why David’s red stemmed roses might be more cold hardy than the green variety. (And my thanks to my daughter Charlotte for allowing me to use her photos here.)

Post-holiday Poinsettia Fatigue

You’ve seen them. The saddest thing ever – a poinsettia, still in its little foil sleeve, tucked into the corner of the doctor’s office/bank/etc. In June.
Photo courtesy of Beth Bonini http://beedrunken.blogspot.com
So iconic, there’s even a rock band in St. Paul called “Dead Poinsettia.”

Every year about this time, I get asked “how do I care for my poinsettia so it will bloom next year?” by friends, students, random callers, and random newspaper writers.

Two words: Chuck it.

Four reasons:
1) Unless you have a greenhouse, you probably can’t replicate the growing conditions that resulted in that lovely, leafy, perfect plant. That poinsettia has been grown under optimal temperature, humidity, fertilizer, and high light conditions. It’s also been sprayed with plant growth regulators – often multiple times, to keep the internodes from elongating. Even with all the breeding for a compact habit, they still want to streeeeetch to be the shrubs/small trees their forefathers were back in Mexico.

2) Day length. Poinsettias are obligate short-day plants, which means they require a long dark period (yes, I know, why don’t they call them obligate long night plants) to become reproductive, resulting in red (or pink or cream) bracts and the little yellow flower-thingy in the center (the cyathia). You can, of course, stick it in a dark room at 5:00 p.m. and remove it to a lighted area at 8:00 a.m., every day for the months of October and November. Until you forget over that long weekend and leave it in the dark for three days…

3) Help stimulate the local “grower” economy. Consumerist, I know, but wholesale and retail greenhouses grow poinsettias to keep their full–time employees working during what is otherwise a very dead time in the ol’ floriculture business. Seldom do these businesses make much of a profit on poinsettia; the plan is to keep everyone busy and generate a little cash flow. Now, some growers/garden centers go above and beyond the usual 6” red point, with unusual cultivars in a range of colors and sizes, hanging baskets, poinsettia “trees”, etc. This has proven to be a great strategy for some enterprising growers.

4) Poinsettia = total whitefly magnet.

In light of the above, I recommend enjoying your poinsettia until the leaves start dropping…then once it reaches the “less than fresh” stage, add it to the compost pile. Next season, go to your local independent greenhouse or garden center and buy a new one. Finally, if you are one of the hard-core, stick-with-it types that has been successfully reblooming the same poinsettia for three years running, congratulations! You have much, much more patience than I do.

Disclaimer: My Master’s research was on poinsettia and the effects of nitrate- N:ammonium- N ratio on growth thereof. Five treatments x 6 replications x 3 cultivars = 90 poinsettias, off of which I picked every leaf and bract to run through a leaf area meter. The latex oozing from the petioles made for a gloppy mess and the whole process took five days. Even 15 years later, I can barely look at a poinsettia without cringing. Pleh.

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Is It Worth Anything?

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?

I think about these things as I peer into my coffee cup…

This winter, we’re working on renovating part of the campus Hort Garden. We’re tossing around lots of ideas/themes, but I’m leaning towards a garden full of “Plants with a Purpose”. Edible, fiber-producing, medicinal…you get my drift. Which brings me to today’s bloggerific topic: beverages.

Mankind has, throughout history, infused or fermented just about every species of flora in an effort to get either perked up or calmed down. These plant potions are often classified anthropologically as, ahem, “ceremonial beverages”. The species that we currently rely on for our daily ups and downs are not native to North America. But that’s not always been the case.

Way before the joys of coffee hit these shores, there was the Yaupon holly (and I am partial to hollies). This thicket-forming evergreen shrub likes “wet feet” and is usually found in marshy areas in the piedmont and coastal plains of the southeast. Translucent red berries grace the female plants in winter – hollies are dioecious, meaning male and female flowers reside on separate plants. The fact that Yaupon is one of few native plants to contain caffeine was picked up on very early by Native Americans – a potent tea brewed from the leaves was called the black drink. Though the scientific name Ilex vomitoria might indicate some unpleasant side effects, it only exhibits emetic properties when a ridiculous amount is consumed.

Sassafras (Sassafras albidum) has been used as both a flavoring and as the main ingredient in teas and soda. The sassafras is a sweet little understory tree, with oddly and variably shaped leaves – with one, two, or three lobes – Dr. Dirr at UGA pointed out to us that they often resemble “racoon mittens” Native throughout the Appalachians, the tree roots were dug up in early spring before while still loaded with sap (where’d ya think they got the name “root beer” from?!). Safrole is the phenolic compound that produces the characteristic flavor. However, safrole is now considered a carcinogen and the FDA banned the sale of sassafras for human consumption in 1976. Extracts used in food and beverages have to be “safrole free” – produced through a commercial process. It’s also a psychoactive compound. This may explain Yosemite Sam’s obsessive-compulsive tendencies and Saturday morning profanity (and I quote) “Rassan, sassan, sassafrasan…”.

Last in today’s line-up of stuff from the woods: Humulus lupulus (the vowel-heavy name for hops). Mmmmm, hops. Here ye, the one or two people that may not know this, that from hops cometh the essential oil that maketh beer yummy. Speaking of oils, get close enough to hop vines on a really warm day and you’ll get a whiff of why it’s in the family Cannabaceae. This perennial vine is native to most of the Northern Hemisphere. The European beer-making strains have naturalized – that is, has spread from plants brought over by colonists in the mid 1600’s. Hops are also dioecious – the female flowers are papery cones about the size of a quarter and the source of all hoppiness (the male flowers are basically useless and just sit around with their feet on the coffee table). The leaves are sandpapery and most have three lobes – sort of reminiscent of a grape leaf. Not only useful to make ceremonial beverages, the vigorous leafy vines provide an excellent screen and can quickly cover up an unsightly fence, shed, or family member. Now that’s a useful plant!

I spent so much time writing this I ran out of time to hunt for plant photos. So here you go: My traveling T.Rex enjoys a nice, hoppy Virgin Islands Pale Ale on a lovely beach in St. John.

Compost Tea? How About Compost Pee!

My news tab in Firefox is the BBC “latest headlines” page. It’s a great place to get pretty darn unbiased news plus the U.K. equivalent of “News of the Weird”. SO, relative to our ongoing discussion of composting…here’s a story ripped directly from the BBC headlines. Follow the link for a video (interview, that is).

Disclaimerage: I nor any of the other Garden Professors endorse this activity, nor any claims as to its usefulness, scientific relevancy, harrumph harrumph, etc,. etc,. etc. We do, however, fully endorse garden-related humor!

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Pee To Help Make Your Garden Grow

Gardeners at a National Trust property in Cambridgeshire are urging people to relieve themselves outdoors to help gardens grow greener.

A three-metre long “pee bale” has been installed at Wimpole Hall.

Head gardener Philip Whaites is urging his male colleagues to pee on the straw bale to activate the composting process on the estate’s compost heap.

He said the “pee bale” is only in use out of visitor hours, since “we don’t want to scare the public”.

He said: “For eight weeks now, male members of our garden and estate teams have been using the outdoor straw bale when nature calls. The pee bale is excellent matter to add to our compost heap to stimulate the composting process; and with over 400 acres of gardens and parkland to utilise compost, we need all the help we can get.

“There are obvious logistical benefits to limiting it to male members of the team, but also male pee is preferable to women’s, as the male stuff is apparently less acidic.”

By the end of the year, it was calculated that the 10 men from the 70-strong garden and estates team will make more 1,000 individual trips to the pee bale, contributing towards the compost for the estate. The estate said it will have saved up to 30% of its daily water use by not having to flush the loo so many times.

Rosemary Hooper, Wimpole estate’s in-house master composter, said: “Most people can compost in some way in their own gardens. Peeing on a compost heap activates the composting process, helps to produce a ready supply of lovely organic matter to add back to the garden.

“Adding a little pee just helps get it all going; it’s totally safe and a bit of fun too.”

Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/uk_news/england/cambridgeshire/8357134.stm

Published: 2009/11/13 00:40:21 GMT
© BBC MMIX

To Prune Or Not To Prune, That Is The Question…

Dabney rules!

“Dabney! No! Wait!” Just kidding. Dabney Blanton, our lovely and talented horticulturist, knows not to prune the Artemisia in the autumn.

I imagine most gardeners have experienced a frost or freeze by now [exceptions: our Southern Hemisphere readers (howdy to Jimbo)…or anyone in the deeeeep south].

The perennials here in Blacksburg have taken a couple of hits; time to start trimming things back. In the Hahn Horticulture Garden and in my own personal garden, we like to leave perennials and ornamental grasses up as long as possible – gives us something to look at besides mulch, plus the wee birdies enjoy it.

But some perennials just look yucky after a freeze.

Case in point: foliage of the popular perennial Artemisia ‘Powis Castle’ resembles graying Kleenexes, hanging on the tips of the branches. HOWEVER, do not cut this back in the fall. It, like many other shrubby perennials, is sensitive to early winter whacking, in my experience, Buddleia and Caryopteris also fall into this category. Apparently the severe pruning sends a message to the plant to break bud – new shoots can appear and then “zap!” Wait until new buds appear in the spring, and be careful not to cut back too hard. I’ve killed a few that way, thinking I was doing them a favor.

“Cut ‘em back, cut ‘em back, waaaaay back!”

The best resource ever on maintaining perennials is Tracy DiSabato-Aust’s The Well-tended Perennial Garden. I should get kickbacks, as much as I’ve promoted this book! Truly a wealth of info – when should you cut it back, will it rebloom if deadheaded, don’t do [whatever] or you’ll kill it – all broken out by genus. Outstanding!

Veggie gardening science – whaddya know?

I just had a long conversation with Michele Owens (of Garden Rant fame) about vegetable gardening. This isn’t one of my strong areas, either professionally or personally (I do have containers of herbs, but that’s as far as it goes). But what piqued my curiosity was her revelation that the vegetable gardening is just as full of myths and misinformation as my field of ornamental landscaping.

I’ve ventured into the realm of vegetable garden science now and then, especially in reference to having soil tests done before planting edibles (good!), the use of CCA-treated timbers (bad!), and companion planting (silly!). Beyond that I haven’t given the topic much thought.

(You know who loves you know who!)

So, readers, what gardening practices out there need to be screened through the sieve of science? Jeff and I have both written about many practices and products, but as you know our expertise is more on the ornamental side.

(Forgive my short blog today. I’ve had some kind of chest crud since last Friday and I’m still wiped out.)

The World According to Chub

Following up on Holly’s theme of “I can’t believe I get paid to do this”, last Wednesday I participated in a walk-through and inspection of the Justin ‘Chub’ Harper Collection of Dwarf and Rare conifers at MSU’s Hidden Lake Gardens in south central Michigan. The Harper collection is widely regarded as one of the premier collections of rare and unusual conifers in the world.

Harper Conifer Collection with fall color background. Photo: Jack Wikle.

A little background: Chub Harper was the former grounds supervisor for John Deere’s world headquarters in Moline, IL, an avid plant collector, and a founding member of the American Conifer Society (ACS). He acquired hundreds of rare and unusual conifer specimens around his home and eventually had to lease a nearby lot for the overflow – demonstrating that ACS also stands for ‘Addicted Conifer Syndrome’. In the early 1980’s Chub donated 300 conifers to Hidden Lake Gardens to establish the Harper collection. All of the plants were balled and burlapped by hand and shipped in three semis to Michigan. Chub continued to add plants to the collection and today the collection includes over 500 accessions.

Chamaecyparis pisifera ‘Filifera aurea’

I met Chub about 8 years ago and with his guidance and inspiration started a series of ‘Conifer Corner’ articles in the Michigan Nursery and Landscape Michigan Landscape magazine. (visit my faculty page for .pdf’s of some sample articles http://www.hrt.msu.edu/bert-cregg/pg5). Once or twice a year Chub would travel from Moline to Michigan to inspect the collection along with members of his conifer posse. To me, the most impressive thing about the walk-throughs was how absolutely ruthless Chub was in disposing of under-performing plants or plants with continual pest problems. “Time for that thing to take a ride on the chipper truck” was a favorite Chub-ism. Hidden Lake Gardens has a garden staff that could spray pesticides or prune away dead material regularly; but Chub wanted none of it. This is not to say that Chub was into organic gardening; as far as I know he had no particular aversion to chemicals. Rather, he felt the mission of the collection was education and that maintaining plants in an artificially superior condition would mislead the public into thinking some conifers were better suited than they actually were.

The Conifer posse at the 2007 walk-through. Chub Harper is 3rd from left, back row.

Chub passed away unexpectedly earlier this year and last Wednesday’s walk-through was the first evaluation of the collection without him. The conifer posse carried on, led by former ACS President Dennis Groh; Chub’s longtime friend Jack Wikle; and Sam Lovall, the landscape architect who developed the original design for the collection. We found homes in the collection for several new specimens including an Abies concolor ‘Charmin’ Chub’ and condemned a few underachievers to a ride on the chipper truck. Chub left many legacies; the most obvious and tangible is the Harper Collection and the staggering generosity it represents. Imagine dedicating half your life to acquiring and cultivating a world-class collection and then simply giving it away. Just as important, however, is the legacy he left with those who knew him, who felt his passion for conifers, and were inspired by him.

Pinus parviflora ‘Cleary’

I see the light!

Here’s the follow up picture from Friday’s puzzler:

As you can see, there’s a street light near the lower half of the maple. (I cleverly hid it behind the utility pole in the first photo.) The green part of the tree never received the message that days were getting shorter, since the street light is bright enough to interrupt the dark period necessary to initiate dormancy.

This is one of my favorite phenomena unique to urban environments. It doesn’t appear to hurt the tree, although the green leaves will die before the tree can scavenge their nutrients. If more of the tree were affected, I’d be more concerned.

Congratulations to Planting Oaks, who nailed this right off. And kudos to those thoughtful alternative explanations, all of which could logically have had an impact on color change.