My summer vacation

I’m following Holly’s lead and slipping into fantasyland today.  Though this part of the country has no snow, it is a typical cool, misty and gray winter morning in Seattle.  So I’m going to a happy place and reminiscing about my summer vacation to Sechelt, British Columbia.

Sechelt (pronounced like “seashell” with a “t” at the end) is a lovely place full of wonderful people (and great gardeners!), but I’m going to focus on the coastal rock gardens at Smuggler’s Cove Marine Provincial Park.  We visited on a day much like the one I’m experiencing now, so there weren’t many visitors.  All the better for us.

Since my interests trend towards plant adaptations to harsh environments, this rocky, salt-sprayed landscape naturally drew my eye.  Trees colonize the bare rock, rooting along cracks and fractures.

Even though we were past the flowering season, these natural gardens were still striking with their miniature plants.  Many of these are cushion formers, and together they formed living patchworks.

And there were still a few wildflowers left as well.


Hot and dry in the summer, constantly sprayed with salt, and living on the thinnest of soils, these rock gardens nevertheless have a rich diversity of plant and insect life.  And all without vitamin B-1, compost tea, Epsom salts, or any of the other products aggressively marketed to the gardening world…truly amazing.

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…

Plant Patents

I love patents.  In fact, I once wrote a novel based on a patent — It was called Patent 22 — If you look this patent up you’ll just find a piece of paper from 1915 which says, essentially, that a search was made for the patent but that it couldn’t be found.  No one wanted to publish it — and reading it now I do realize that it does need some serious work.  Still, I think this little tidbit gives you a little bit of an idea about my interest in patents.  (The paper on file at the patent office is below):

Anyway, here’s the thing that people don’t know.  There are three ways to protect a plant from someone else “stealing” it: Plant Patents, The Plant Variety Protection Act, or a Utility Patent (which is what you or I usually think of when we think of a patent).  The Plant Patent Act passed in 1931 and it is the way that most plants are protected today.  Plants like the Honeycrisp apple which are propagated vegetatively (using cuttings or grafting) are usually protected with this type of patent.  The second type of protection is the Plant Variety Protection Act of 1970.  This Act lets you protect seed propagated plants.  With these two types of protection you wouldn’t think that any other type would be needed — but the Supreme Court has twice ruled that plants can be protected using Utility patents (once in the 1980s and once in the early 2000s).  So, what is the problem with that?  Well, basically, the problem with that is that, while the other ways to protect plants allow for the use of those plants in research or for breeding and farming, using a utility patent prevents anyone from using the patented plant from doing anything with that plant without permission from the patent holder.  And, basically, an entire species of plant can be patented — it has been done before with a bean that someone brought from Mexico into the US — he cornered the market on the bean and noone could sell or breed the bean without his OK.  Sounds insane doesn’t it?  Just my first thought on a cold Thursday morning.

All Right, Linda; I’ll See Your Paraheliotropism and Raise You a Nyctinasty

Amicia zygomeris is a cute little herbaceous thing I picked up on a visit to Plant Delights nursery back in October. For $13, I wanted to be sure it survived the winter, so it’s been in our kitchen garden window, just waiting for spring.

Soon after putting it in the window, I had an “oh no, I’ve killed it” moment one evening.  All the leaves were drooping, yet the soil was moist.  The next morning, it seemed to be back to normal.  The following night, droop city again.

Ah HA! Nyctinasty* at its finest – plant movements to the circadian rhythm.  Tropisms are growth responses, while nastic movements are just that  – reversible movements.  There are other “nasties” out there – photonasty is movement in response to light, hydronasty –  water, etc.   The classic example is Mimosa pudica – sensitive plant – the little leaves fold to the touch (thigmonasty).

Legumes are particularly prone to this – check out the bean plant flapping its leaves in time-lapse video at the “Plants in Motion” website (U. of Indiana Biology Department).  The movement comes from changes in turgor of the cells that attach the leaf petiole to the stem. This spot’s called the pulvinus – think of it as the leaf’s armpit.  What do plants gain from this daily spreading then folding of leaves? Folks have been pondering this for centuries. Darwin wrote about it in “The Power of Movement in Plants” (1880).  Though the biochemical mechanism has been discovered, I don’t believe any conclusions have been reached as to "why".  


Amicia zygomeris in the evening. The common name, courtesy of Tony Avent, is  “Gotta Pea". I am not making that up.

*BTW, Nyctinasty is also the name of a pop band from Manila. Must be a biologist or two in the bunch.

Friday puzzle answer(s)

Wow!  What a lot of great brainstorming over the weekend!  I would venture to say that The Garden Professors have the smartest students in the world.

On to the answer…or answers.  First, the phenomenon.  It’s called paraheliotropism – literally, a movement to protect (the leaves) from the sun (yes, Trena, it is a tropism!). This is the opposite of another phenomenon called heliotropism, or solar tracking.  Sunflowers famously do this, as do a number of arctic species that collect solar warmth for the benefit of their pollinators.  (An aside:  if you have never watched David Attenborough’s The Private Life of Plants you must add it to your Netflix queue.  Right now.)   

But our saxifrage (thanks, Holly! I’m such a taxonomy imbecile) is reducing solar exposure by positioning its leaves in parallel to the sun’s rays.  This is a reversible movement and helps reduce photooxidative stress, leaf temperature, and water loss.  It’s an important strategy as the newly emerging leaves are actively expanding.  If turgor is reduced by high temperature or water loss, so is the final size of the leaf. 

Finally, these rapidly expanding leaves have relatively thin cuticles (if they were thicker the leaves wouldn’t be able to expand as well).  The cuticle gives further protection to the leaf from water loss due to heat, drought, wind, or even late season freezing events (thanks for that addition, John!).  The cuticle will mature after the leaf has reached its full size.

So, as Foy suggested, this is a way for leaves to "harden off" and reach full size before exposing themselves to the sun.  Aren’t plants cool?

And you are all such great participants!  Group hug!  Now, back to work.

Friday Physiology Fun Followup

Astute readers pointed out several morphological adaptations found in drought-tolerant turf weeds:  fleshy taproots, reflective leaf surfaces, etc.  What we can’t see is what many of these plants do physiologically – and that’s photosynthesize using a biochemical pathway that temperate turfgrasses don’t possess. 

This pathway, called C4 photosynthesis, contains some extra preliminary steps not found in plants using traditional (C3) photosynthesis.  The downside:  it takes more solar energy for the plant to photosynthesize.  The upside:  these extra steps allow the plant to "fix" carbon (transforming it from gas to solid) faster, especially when it’s sunny, warm, and droughty.  Practically speaking, this means that C4 plants do not have to keep their stomata open as long and they conserve water more efficiently than C3 plants.

So in the summer – when it’s hot, sunny and dry – the C4 plants in your lawn are operating under optimal conditions, while the C3 grasses go dormant.  The tables turn when the seasons do:  cool, moist conditions favor traditional photosynthesis, and the C4 plants are overtaken by the turfgrasses.

Cool, huh?

Friday physiology fun

It’s still cold and wintery, so let’s imagine ourselves in a happy place…warm, sunny, dry…with dead lawns.

As the photo shows, the turfgrass is dead; this happens every summer during the Pacific Northwest’s droughty summers.  Yet many of the weedy species are obviously thriving.  Why?

Remember, this is a physiology quiz.  You can discount herbicides, fertilizers, etc.  This is a cool (no pun intended) adaptation that many species native to dry, subtropical to temperate environments possess.  And there are serious implications for water use related directly to this adaptation, or lack thereof.

Let’s see lots of brainstorming on this – no points deducted for trying!  (And if you are a true ecophysiology geek, let other people try first before posting the answer.)

Friday fun, part 1

This posting is for Holly, who I am sure is desperately trying to finish her annual review.  I feel your pain!  And I’m going to add to it today.


The poinsettia in these photos is not from this Christmas, but from 2008.  You can see it thriving happily in its office environment.  I’m told by its caretaker Nick (a nongardener) that it has no bugs or other problems, and seems very happy.  And it’s blooming, without the benefit of the extended night period.  (The post-it notes are instructions to its care when Nick is away.)

Apparently SOME people can easily grow poinsettias well past their expected holiday life span.

Baptisia: Beyond the Blue

The Perennial Plant Association recently released the identity of the PPA Plant of the Year – for 2010 it is Baptisia australis (False Blue Indigo).  Various blogs have noted this (including Garden Professor fave Garden Rant) and I’ve read some interesting comments, both pro and con.

True story: I asked for Baptisia at a small rural garden center years ago; the owner said “Don’t have any; but I think I have a Methodist running around here somewheres…”  Badda-bump.

Me? I think it is a truly wonderful native perennial. I’ve had great success with it in both Zone 7b and 6a and teach it as a “bread and butter” component plant for the mixed border. As a PPA member, it certainly got my vote on the last ballot (beats the hell out of last year’s Hakonechloa macra ‘Aureola’ – hard to say and even harder to grow in the Southeast).

The great thing about the PPA “Plant of the Year” program is not just in the promotion of that particular species, but that it opens the door for other cultivars and hybrids.  Two of my favorites:  Baptisia x ‘Twilite Prairieblues’ [sic] and B. x ‘Solar Flare’. Both were bred and/or selected by that delightful genius Dr.Jim Ault, of the Chicago Botanic Garden, and introduced through the Chicagoland Grows program.  Pictured are plants that are have only one full year of growth after purchase and planting (nice full gallons to start with; from Saunders Brothers nursery, located in the greater metropolitan area of Piney River, Virginia).

x ‘Twilite Prairieblues’ is a cross between B. australis (our PPA winner) and B. sphaerocarpa – a shrubby, tough little guy with yellow flowers. This fortuitous romance yielded quite a jaw-dropping color combination of dusky violet with a yellow keel petal. These puppies are in our campus horticulture garden.

Now take a gander at B. ‘Solar Flare’ – a “complex hybrid, probably open-pollinated” of B. alba (white-flowered), B. tinctoria (yellow-flowered), and B. australis. This is what can happen when a whole bunch of species and hybrids are planted close together (cocktails and/or bees are usually involved). From my own garden:

Buttercup-yellow fades to warm apricot, then to plum – the thing absolutely glows in the late afternoon sunshine.  Gosh, I miss summer…


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.)