Propagating in the air

Most gardeners that I know have tried to produce roots on stem cuttings from plants that they like.  Sometimes this turns out well for them, particularly if they are working with what we call an easy-to-root species, and sometimes it turns out poorly.  OK, in all honesty, it often turns out poorly.  The problem is that plants like very particular conditions when they’re growing roots and the typical gardener is going to have a tough time providing these conditions.  So here’s an option.  There is a method of propagation called air-layering which works on many plants that stem cuttings won’t work on and which doesn’t need all of the specialized equipment either.  It’s not a sure-fire technique, but it’s more likely that the average gardener will get this technique to work than any other (with the exception of seeds).

Here’s how it works.  Select a small branch from the plant you want to propagate.  Find a point on the branch about 6 to 12 inches from its apex and then cut out a ring of bark around the circumference of the tree.  This will allow water and nutrients to flow into the branch (assuming you didn’t cut too deep), but it won’t allow the carbohydrates produced in the branch to flow down the stem — instead they’ll be stuck where you made your cut and be used by the plant to produce new roots.

Around the cut you may apply a rooting hormone.  This will help the root production to some degree.  To keep the wound moist apply a heaping helping of moist peat and keep it in place with plastic wrap — or a cut up sandwich bag.  Wire ties, elastic bands or string will hold these in place.  Now you just sit back and wait.

It usually takes anywhere from 4-8 weeks for roots to emerge (you’ll see them when they do because they’ll push up against the plastic wrap).  Once the roots are there plant your new tree/shrub/perennial in it’s own container just like you would any new plant, care for it as you would any other plant, and then plant it out if you so choose (I like to keep young plants like this in a container for at least a few months — the landscape is usually a harsher environment than a container, and so the time in the container gives it a chance to get stronger and store needed nutrient reserves.)

Five little lavenders – an update

Long-time readers of our blog might remember my August 12 column (linked here for your convenience).  You saw my giant lavender plant devolve into 5 small plants with tiny spiraled root systems that put Marge Simpson’s beehive to shame.  In any case, I promised to keep you up-to-date with their progress.

Transplanting in August is a risky proposition, especially when you prune out root defects.  Nevertheless, all but one of the five survived the summer and here they are earlier this spring:

The one that didn’t make it was in the upper left corner of this south-facing landscape, where there is a lot of reflected heat from the nearby bricks and concrete.  (You can see the empty spot where it was in this photo.)

If you haven’t tried corrective root pruning before, I’d encourage you to try it with an inexpensive shrub.  Your best bet will be older containerized plants in the “sale” section of your nursery.

John Bartram Lives!

Yep, there he is. Showed up at our state Master Gardener College, just last week. I even went to dinner with him. The snake-on-a-stick startled the bartender just a bit.



The elder Bartram (his son William was also a great botanist and explorer) was the Royal Botanist to King George III and a member of the Royal Academy of Sciences, Stockholm. As with many of the Great Plant Explorers, his life combined botany with politics,
adventure, and lust [for plants,anyway]. Someone should make a movie…

Probably best know as the discoverer of the soon-to-be-doomed little tree, Franklinia
alatamaha, he also was responsible for the introduction of lots of
other North American native garden staples such as rhododendrons,
Kalmia, and deciduous magnolias. Bartram died in 1777, but has recently been resurrected by Kirk Brown, master thespian and all-around talented guy.

Kirk works with Joanne Kostecky Garden Design in Allentown, PA, and is a director for Garden Writers of America.  But his passion for the life and times of fellow Pennsylvanian John Bartram takes the audience far beyond the usual gardening lecture. His presentation "John Bartram: The King’s Gardener" unveils the travels, collections, and psyche of the father of the nursery industry in the original thirteen colonies. I love the review by Stephanie Cohen (The
Perennial Diva!) "Kirk Brown did not imitate John Bartram, he actually
became him…anyone who has an interest in history or horticulture will
be spellbound by this presentation."  She’s absolutely correct. For more on John/Kirk, check out www.johnbartramlives.com.

Questions on sustainability

Linda’s recent post on the sustainability of topiaries got me to thinking, is any horticultural practice sustainable?  And, does it matter?

 

Picking up on the topiary theme I thought of the ultimate form of tree manipulation, bonsai.  I few years ago I visited the National Arboretum in Washington DC, which includes an incredible bonsai display.  Some of the bonsai specimens in the collection originated in Japan and are over 300 years old.  Is 300 years long enough to consider this a sustainable practice?  Does it matter as long as there are individuals willing to devote the time and effort to tend and prune these awesome and inspiring plants?

 

More recently I visited the International Rose Garden at Washington Park in Portland.  Established over 90 years ago the garden is one of the premier attractions in Washington Park and in Portland.  Maintaining the garden, however, requires paid staff and an army of volunteers.  Is 90 years long enough to consider this sustainable?  Does it matter as long as the city is willing to commit resources and volunteers are willing to line up to dead-head and pull weeds?

 


Closer to home, I maintain about an acre of my place in lawn and various beds – trees, shrubs, herbaceous perennials and even a few (gasp) annuals.  Is this sustainable?  Does it matter as along as my family and I enjoy our surroundings and are willing to commit the time and effort to mow, weed, edge, prune and dead-head?

Clematis mystery solved

Friday’s quiz was a tough one. Bernadette and Lisa B. gave it a good shot, guessing that this might be a phosphorus deficiency. While they’re on the right track (it is a nutritional disorder), the mineral of interest is iron, and it’s a toxicity problem, not a deficiency.

Under wet conditions (the affected Clematis is in the part of our landscape with a perched water table – see the March 15 posting), iron is predominantly in the Fe+2 form (ferrous) rather than the Fe+3 form (ferric). The ferrous form is easily taken up by roots, and when leaves accumulate too much iron they turn reddish-brown.  This diagnostic characteristic is called bronzing, and it’s different than the reddening caused by anthocyanin accumulation.  (As an aside, nonagricultural landscapes rarely have phosphorus deficiencies and are more likely to contain excessive levels of phosphorus.)

Finally, all this talk of iron has reminded me of one of my favorite chemistry puzzles – see if you can figure out what this is:

Give up?  It’s a ferrous wheel!

Friday quiz – a tale of two clematis

These two Clematis are the same cultivar growing in my landscape about 15 feet apart. Both are growing on a fence facing north. Compare the leaves of the two:


Normal, happy Clematis


Not-so-happy or -normal Clematis

What do you think is causing the leaf discoloration? Very large hint: this is not a biotic stressor. Another hint: you’ve seen this part of our landscape before…back in March. For full credit, identify both direct and indirect environmental stress (in other words, [1] what is directly causing the discoloration in the leaves, and what is allowing [1] to occur, thereby causing stress indirectly)?

Answers on Monday – have a happy 4th of July.!

Organic farming study at – gasp! – a research university

There is a common misperception among some that university researchers are in the pocket of Big Ag (see June 11 and 13 posts). So here’s a link to an article in today’s Seattle Times about the benefits of organic farming from a study at Washington State University.  The research was published in Nature (one of the most revered of the scientific journals).

Cornmeal myth busted

As my colleague Fred Hoffman says, the horticultural silly season is upon us. This week I heard from one of our European readers, questioning the use of cornmeal as a fungicide. He referenced an online article entitled “Cornmeal has powerful fungicidal properties in the garden.” He hadn’t been able to find any reliable information and thought it might make a good topic for our blog. So Johannes, this rant’s for you!

If you’ve followed the link to column in question, you’ll see that the original “research” is attributed to one of Texas A&M’s research stations in Stephenville, TX. But it’s not really research – it’s just an observation on what happens when you don’t plant the same crop two years in a row; in this case, rotating corn and peanuts reduces peanut pathogens. This is hardly news – it’s one of the reasons agricultural scientists recommend crop rotation as part of an IPM program. And have for decades.

Then we’re referred to “further research” (at an undisclosed location) where cornmeal was shown to contain “beneficial organisms.” Well, no, cornmeal doesn’t contain organisms, beneficial or otherwise. Microbes can grow on cornmeal, and in fact cornmeal agar is commonly used in labs as a growth medium for many species of fungi. And has been for decades.

Nevertheless, we’re informed that a gardening personality has “continued the study and finds cornmeal effective on most everything from turf grass to black spot on roses.” This is directly refuted by Dr. Jerry Parsons, who by happy coincidence is an extension faculty specialist at Texas A&M. His informative (and hilarious) column on brown spots in lawns states “Lately there have been claims made that corn meal and a garlic extract is effective. This is absolutely false! Everyone trying to do the “environmentally friendly-to-a-fault” thing have been wasting their money. They would have been better off making corn bread and using their garlic for cooking purposes!”

Dr. Parsons continues: “Let me explain how these University tests and recommendations have been misrepresented in a desperate attempt to find an organic fungicide. The corn meal was investigated by a Texas A&M pathologist as a way to produce parasitic fungi used to control a fungus which occurs on peanuts.” (This directly relates to my earlier point that cornmeal agar has a long history of use in fungal culture.)

It boils down to this: if you have a healthy soil, it will probably contain diverse populations of beneficial microbes, including those that control pathogenic fungi. You don’t need to add cornmeal – it’s simply an expensive form of organic material.  So you can ignore the directions in the article on how to incorporate cornmeal into the soil, or make “cornmeal juice” to spray on “susceptible plants.”   Just nurture your soil with (repeat after me) a thick layer of coarse organic mulch.

(As a footnote, let me say how annoying it is when gardening personalities grant themselves advanced degrees or certifications in their titles.  C’mon folks – if your information is so great, do you really need to pretend you’re someone else?)

(Another footnote: I discussed this myth more in 2012. Be sure to check this link out too.)

UPDATE: Since this is a myth that refuses to die, I’ve published a peer-reviewed fact sheet on the topic. Feel free to pass on to others.

The Other Lamb’s Ears

I’m assuming even you tree people (aka other
Garden Professors) are familiar with the soft, silvery leaves of Stachys
byzantina or Lamb’s Ear (variously Lamb Ears and Lamb’s Ears).  Not to
disparage S. byzantina, but in our part of the world it looks like a
pile of wet dryer lint in the winter; and can become similarly
disfigured during a hot, wet summer.  Spring brings bright,
pet-able new ears, followed by woolly flower spikes that could serve as
Q-tips for Shrek. Runs/reseeds like a banshee in my home garden.
As
Dr. Allan Armitage notes, “We’ve been lamb-eared to death.”

But there are several other species of
garden-worthy Stachys, one of which is garnering lots of attention in
our campus garden at the moment. Behold, Stachys officinalis ‘Hummelo’ – Wood Betony or Alpine
Betony.

Also sold under S.
officinalis and S. densiflora. Most nurseries seemed to have settled on
S. monieri, but that specific epithet does not appear in the ITIS
(Integrated Taxonomic Information Systems) database. Armitage lists it as a cultivar
of S. officinalis and then has S. monieri as a separate species.

Regardless of pedigree, ‘Hummelo’ is a terrific perennial.
Clumps of glossy green scallop-edged foliage are topped with
spikes of rosy-lavender flowers throughout the summer. Heat- and
cold-tolerant; it’s hardy from Zones 4 to 8. Full sun or part shade,
drought tolerant, deer resistant…what’s not to like?

Back to the ubiquitous version of lamb’s ear…we
have a superior selection of S. byzantina with the fabulous cultivar
name of ‘Countess Helene von Stein’. Rarely flowers, and has bigger, tougher leaves that hang in there regardless of humidity. Very effective
when barked at students with a Teutonic accent: “Countess Helene von
Shtein! You vill learn dis plahnt!”  You may find this in
the U.S. under the comparatively boring ‘Big Ears’.