Is This Really a Good Idea?

Transgenic plants have been with us for well over a decade now.  I have had the opportunity to work with many of the tools used for this technology, though most of that is far behind me (over 15 years now since I “ran a gel”) — I’m much happier being outside or even in front of a computer writing than in a lab.  Fortunately I have a number of “lab rat” colleagues so I’m relatively up to date on what’s going on and what “gene-jumper” scientists can and can’t do.

To make a long story short, over these years transgenic plants have proven to be useful in some cases (by reducing the use of certain dangerous pesticides), and concerning in others (because some genes have escaped cultivation).  I’m not going to go into the crazy ins and outs of the benefits and drawbacks of genetic engineering here except to give you my general opinion which is that every case needs to be handled individually.  I do not believe that this engineering is, in and of itself, a bad thing.  That said, I do believe that genetic engineering could get us into trouble if we’re not careful.So, with that little disclaimer I thought I’d mention something that I question — I’m not going to call it bad — but maybe it is.  There’s an “artist” at the University of Minnesota — Eduardo Kac, who had some of his genetic material placed into a petunia so that some of the proteins from his body were expressed along with the petunias.  I don’t have a picture of the petunia itself, but here on the St. Paul campus of the University of Minnesota you can see this structure, created by Kac, which is a graphic representation of a protein from the petunia.

(It was around 20 degrees outside when I took this shot — positively balmy compared to what it’s been like).

Anyway — as I said above — Though I have some concerns, I’m not opposed to using biotechnology for the “good of man.”  Nor am I afraid that Kac’s creation is dangerous — from what I know it was kept in a closed system and the petunia was ultimately destroyed — not that it would have been particularly dangerous even if it had been released.  But….to me anyway….This seems like a frivolous use of a powerful tool (that tool being the ability to move genes from one organism to another).  I don’t know if I’d call it bad….but the words Wasteful and Inappropriate come to mind.

By the way, though I know less about it, it seems that Kac also transferred genes into a rabbit for the sake of art.  But this is, after all, a horticulture blog so I thought I’d stick with plants!

Why I dislike rootgrafted plants

I’m pretty much a live-and-let-live person in terms of plant choices (as long as they’re not invasive).  But I’m becoming convinced that oddities grafted onto hardy rootstocks are poor choices, because the rootstock always seems to win.  I posted one of these several months ago (see October 28, 2009 ), but just today have just found the poster tree for my anti-rootgraft movement.

A little backstory.  I’m currently out at the Washington coast, trying to get some writing and seminars done without disruption.  Today I had to make a trip into Aberdeen, the horrors of which will have to wait for another post.  Before going back to my retreat, I tried to renew my enthusiasm for life by seeking out bad plants.  I was well rewarded.

I have to give my daughter Charlotte credit for spotting these lovelies.  There were two of these $50 Betula pendula ‘Youngii’ trees available.  I felt like I’d stumbled upon the next winner of “America’s Next Top Model.”  I took pictures from every angle, full shots and close-ups, for your viewing enjoyment.

Note that the “unusual deciduous tree with pendulous branches” is a grafted tree, evidenced by the differences in girth at the grafting point.  You’ll also note the appearance of vigorous watersprouts emerging from below the graft.  (The bamboo stake to the left lost it function years ago, but is still adds an unexpected pop to the overall composition.)

And here she is in her full beauty!  The “S” curve of the scion is bisected longitudinally by two watersprouts, forming a giant $!  I do have to agree with the tag at this point – it certainly is “an excellent accent or specimen plant” for the Island of Misfit Grafts.

Finally, please enjoy yet a final reason I don’t like grafts:

(Hint:  Note the glue glob.)

And now for something completely different…

From this week’s e-mail file…

“Dear Dr. Cregg:

As I’ve done for many year, this year I harvested my “wild” Christmas  tree from the Huron-Manistee National Forest. I cut the tree at ground level. Soon after I brought it home, it started sprouting new light green clumps of needles at the tips of many branches. Is the tree actually growing? It doesn’t seem possible that it’s still alive, but it seems to be thriving and I hate to toss the tree to the curb if it’s fighting for life. I am tempted to leave it in the tree stand to see what happens….”

Pat M.

Midland, MI

 

Dear Pat:
The tree is dead, it just doesn’t know it yet.  Depending of the species, some Christmas trees will break bud and begin to grow once they are brought indoors.  The tree is still alive in the sense that its needles are still carrying out photosynthesis and water is still moving up the trunk to the needles.  But since the tree has no roots and no way to produce any new roots, it has no prospect for long-term survival.  The phenomenon you’re observing is common in some spruces and other conifers adapted to cold regions.  Before you cut the tree, the buds were exposed to enough cold to meet their chilling requirement to overcome dormancy – the only thing that keeps trees in wild from growing at this point are cold temperatures.  Once you brought it indoors, the tree ‘thought’ is was spring and started to grow.  If you or a family member want to do a little science project you could keep the cut end in water and see how long the tree lasts.  Eventually, however, the conducting elements at the cut end will begin to plug with resins and the tree won’t be able to move enough water to meet its needs and will expire.

Regards,
Bert Cregg

 

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).


Baptisia 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…

Sigh.

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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If I’ve seemed distracted for the last few months, this is why

I just got this today – it releases in February!
Isn’t it a great cover?

And this one came out the week before Christmas – my holiday gift to myself!  (You try riding herd on 21 different authors and see if you like it!)

Getting these books done was a major milestone, and I hope that this year I might have time for some new projects.

Happy New Year!