It’s a Bird! It’s a Plane! It’s a …Butt?

So we last left off discussing the issue regarding the fact that the point is incumbent on us that one can’t refer to a native as "invasive" withou…


What’s that??!
There! Amongst the Pachysandra!

Is it a freshman? Perhaps passed out in our campus garden in despair after yet another stinging defeat of the Hokies?

Nay, ’tis a pair of Calvatia gigantia – Giant Puffballs.

'Tis not a butt

Pretty impressive, though. Note toes for scale. Unfortunately, with all the foot traffic in our garden, there’s little chance they will make it intact to the "fun stage" (official mycological term for when the exterior turns dark ‘n crispy and the internal spores floof out in huge clouds upon poking).

I fully expect our Pacific Northwest people to be all "You should see the size of OUR Calvatia species!"
Bring it.

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.)

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
, he also was responsible for the introduction of lots of
other North American native garden staples such as rhododendrons,
, 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

Creative Uses For Old Water Breakers

Why, oh why, can’t someone engineer a sturdy, long-lasting, horticulturally-correct water breaker.

We have, at last count, six hoses in use at our very spread-out garden & farm.  I go through a lot of breakers, and am down to two, which I rotate around.  In dire need of some new ones (as well as a huge bale of TP), I perused the garden aisle at our local big box (rhymes with “Target”).  Pistol grip schnozzles abound – these things that propel the water
like a 95 mph fastball.  Just what your plants want. Some had the “dial” for various water flow patterns, but these are never satisfactory.  Not a single real water breaker for plants among the 20 choices. So I shall do mail-order from FarmTek.

Dramm seems to makes the only functional water breaker, but alas, most of what’s in my busted-breaker-bucket are old Dramm heads (at $10-$12 a pop). Their commercial line is a bit better than the consumer items, where a rainbow of colors seems to be more important than structural integrity.  Anyone who’s worked in a commercial greenhouse has used their aluminum models or the plastic RedHead soft flow breaker, The only solid brass item in their line is the super-fine Fog-it Nozzle… I’ve had the same one since 1996.

A solid brass version of the full-size breaker would be great.  The point of failure (always) is the interface between the screen plate and the body/shell.  I hate replacing things. I’d pay for quality.

Hammer Time!
Obsoive.  My ingenious partner uses a water breaker body to keep bamboo from splitting (further) when pounded.  Principle of transference of impact from smaller area to larger surface, etc.  Tomato stakes finally installed!

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.

End of the Semester Evaluations

It’s that time of the semester to hand out the lovely SPOT evaluation forms (Student Perceptions Of Teaching) here at Virginia Tech. Students fill in the circles (number 2 pencil of course) as to how you rate as teacher, your knowledge of the field, the value of the textbook, etc. A box is available, though seldom used, for students to hand-write comments – to many of us, the most valuable part of the evaluation process.  So as I was distributing the scan forms, I was thinking about feedback.  It seems that in life, where feedback or comments are totally voluntary and no forms are forced upon you, the energy required to send a letter, email, or comment is often (not always) mustered only for negative feedback.

In the case of this blog (and many others), we have enjoyed amazingly positive and inquisitive comments, even if it’s just two or three for each post, as well as the occasional barb (just fine with me) . Our biggest "commentroversy" came with Linda’s post about International Ag Labs – the ensuing hoo-ha resulted in 102 comments due to a "defend the ship!" email sent out by the company, and many were decidedly in opposition to the post.

All to say: we’ve been at this Garden Professors thing for about 9 months now, and Linda, Jeff, Bert, and me would like to know what YOU, our dear blog-readers, THINK. Some of you  comment fairly regularly – thank you Jimbo, Deb, Hap, Paul, et al. But I also know that’s just the tip of the iceberg.

Please take a moment, if you can, to weigh in: 

– Are you happy with the diversity of posts, or do you want "science and only science" e.g. less garden products/pantyhose posts?

– Do you enjoy reading about our work with students? No? Well, tough! (just kidding).

– What topics would you like to see addressed in future posts by our GP squad? Can be broad or specific. [More on perennials, you say? 😉 ]

– Overall thoughts? The value (or lack thereof) of this blog to you and your garden, nursery, or landscape firm?

Any and all feedback will be appreciated by all of us here at The G-Prof.

So go ahead and comment, even if you’ve never done it before!

Flounder barfs in 3...2...1...
Don’t make us summon you to the Dean’s office! (Note #2 pencils at the ready.)

Flounder throws up in 3...2...1... Flounder barfs in 3...2...1...

The Glories of The Winter Greenhouse

I’m a Southerner. With a capital “S”.  Which is why I am Suffering, with another capital “S”. Here in the Blue Ridge mountains of western Virginia, we have officially surpassed Anchorage and Denver in total snowfall for the season. Today’s batch adds up to 24″ on the ground at our farm.

Blueberries in the snow. If one more person says “Probably good for all the insect problems,” I’m going to get violent.

The chickens are not happy. They’ve been cooped up (ha! I didn’t really mean to do that!) for 10 days straight. I myself suffer from cabin fever, limp hair, seasonal depression, and a persistent cough.

Hell no, we won’t go!

What keeps me from going totally nuts? Only the best $12,000 ever spent – no,no, not granite counter tops…it’s our very own greenhouse. This modest 24′ x 48′ polycarbonate sheet hoop house may not resemble a Victorian conservatory (you can get one of those beauties here), but it works like a champ.  Yes, we have greenhouses on campus for research and teaching, but that’s work; and pet plants are frowned upon.

Nothing beats your own private winter hideaway. My plant-diva-friend Elissa uses her crowded greenhouse for not only her immense plant collection, but also a festive (if cramped) happy hour.

As sleet pelts the roof, I’m surrounded by green: tropical plants dug up from the garden before frost and those “pets in pots” accumulated from hither and yon.  The humidity is wonderful – I can hear my skin go “aaahhhh” after a couple of hours.

Herd o’ Agaves and succulents. They’re perfectly happy with the cool temperatures – several are blooming.

I’ve dreamed of one for years; then finally took the jump 16 months ago. Again, it’s nothing a homeowner’s association would ever approve of; just a commercial-grade, heavy duty, Quonset-type production house. Stylistic concerns were sacrificed for square footage. The most common complaint from home greenhouse owners is “I wish I had built a bigger one.”

The other concern is heating costs. It has a propane heater, and propane’s not cheap, nor environmentally friendly. But we run it pretty darn cold – around 48 F night temperatures, which certainly helps. Are the tropicals thrilled? Not really, but they’re alive and hanging in there (however, the begonias are really grumpy right now).

Some PVC pipe + overhead misting + heating mat = broccoli spinach, and basil seedlings, happily germinating at a 75 F soil temperature, despite an air temperature below 50 F. Basil?! Yes, I realize I’m totally jumping the gun timing-wise here, made worse by the fact that I teach both greenhouse management and ornamental plant production (do as I say, not as I do!).

Yep, more fun than you can shake a shovel at!
I’ll take your questions, comments, and snowballs now…

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
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.


Inspecting nursery plants, part IV

(Note:  this is a really LONG post.  Not in text – but in photos!  Sorry for all the scrolling.)

I don’t know about you, but after spending three weeks on my hands and knees looking for trunk rots, surface roots, and suckers, I’m ready to become bipedal again.  So today let’s look at trunks – and what shouldn’t be missing on them.

Many young trees have numerous short branches along their trunk, as shown in the photo below:


Unfortunately, many nurseries and gardeners think this looks scruffy, and respond by pruning these branches off, leaving a tree such as the one in this picture:

Personally, I think these trees look like lollipops, but aesthetics aside, this type of pruning can inadvertently damage young trees.  Their bark is often thin and sensitive to environmental stress – especially sunburn.  Without those short branches deflecting the sun from the bark surface, the living tissues under the bark can be killed, creating dead patches on the trunk:

How can you tell if the tree you’re considering has been improperly pruned?  Just look for those tell-tale pruning cuts, as a close examination of the lollipop tree reveal:

In time, these trees develop thicker bark, and the lower branches are gradually shaded out as the crown increases.  Be patient!  Let your trees be a little fuzzy when they’re young.  They’ll grow out of it.

Inspecting nursery plants, part lll

By now you’re probably ready to stand up, brush off your pants, and stretch your back after crawling around looking for surface roots and root crowns.  Not so fast!  There’s one more thing to look for – and to avoid.

Take a look at these two photos:


You can easily see the suckers at the base of these trees.  Whether or not they are actually suckers (coming from the roots) or watersprouts (coming from the base of the trunk) doesn’t matter.  Their presence in single trunked species warns of problems underground.  You’ve probably seen landscape trees respond to crown stress by suckering.  In this situation, my diagnosis is that the roots are so stressed (buried too deeply, structurally malformed, etc.) that they are unable to provide enough water to the crown.  Thus, the plant responds by creating a shorter crown (the suckers) which is easier to keep supplied with water.

In both of the above cases, these were the only individuals of their species in the nursery that were suckering.  That makes it easy to avoid purchasing them and their stressed root systems.

This is not such a problem with species that tend to form thickets, like our native vine maple (Acer circinatum) below:

Bottom line:  know the natural habit of your trees and shrubs before you buy them.  If they are single trunked species, don’t be a sucker – avoid suckers!