Hits & Misses: The 2007 Perennial Plant of the Year & A Changeling Poinsettia
Question of the Week: How Long Can I Leave My Poinsettia in the Car?
Business: Pesticides and Non-Target Organisms
Science & Technology: Scouting, Be It Professional or Amateur

Our latest cold and cloudy snap may have you cranking up the heat in your home to warm chilly bones. Although the increased heat may bring you some relief, it actually stresses your houseplants. For plants, an increase in heat without a corresponding increase in light is akin to a human crash diet program where you burn up more energy than you take in. When light levels are low, the best temperature management approach for houseplants is to drop the temperature by a couple of degrees where your plants are located. For example, if you have your thermostat set at 24˚C, drop it to 22˚C or even 20˚C—if you can stand it. Once the sun returns (and it will!), you can raise the temperature. The pros to this temperature strategy are healthier plants and reduced energy costs. The cons are the necessity of wearing heavier clothing around the house and an increased likelihood of divorce.

Hits and Misses
Hits: ‘Walker’s Low’ Hits a High
The Perennial Plant Association has just awarded nepeta ‘Walker’s Low’ the title of 2007 Perennial Plant of the Year. Walker’s Low has attractive silver-green foliage and dark-purple flowers and is hardy from Zone 3–7. This nepeta grows about 90 cm tall and spreads 60–90 cm, making it one of the largest cultivars available. I like nepetas because they are tough, pest-free plants. They are also often described as ‘aromatic,’ which I suppose is true, but aroma can mean a variety of things to a variety of people and I can’t say that nepeta is on the top of my fragrant-plant list.

Misses: A Changeling Poinsettia
I love the ‘Visions of Grandeur’ poinsettia. It’s a big, bold vigorous plant with soft, peachy-pink ‘pillow like’ bracts. The problem with this variety is that it appears to be unstable. I don’t mean that it has a predilection to falling over or that it has deep-rooted emotional problems. Rather, the stability problem I’m referring to is variety stability. In other words, scattered among the Visions of Grandeur crop are a few plants that have red colouration instead of peach-pink, which indicates that this variety would rather be like one of the parent plants used to create it. This doesn’t mean that if you buy a Visions of Grandeur poinsettia, it will suddenly change its appearance in your home, but it might mean that this variety may not be available to growers much longer because of the stability problem.

Question of the Week
How Long Can I Leave My Poinsettia in the Car?
I answer this frequently asked question the same way every time: Don’t leave these plants in the car with the heat turned off for any length of time. Poinsettias are cold sensitive and you never know just how long those quick stops at the store will really take! I also always advise prospective poinsettia purchasers to insist that the store they are buying plants from wrap each plant from top to bottom in a paper sleeve. A plastic bag over the pot just isn’t sufficient enough to protect plants in our climate, even for the short jaunt from store to car and car to house.

Business
Pesticides and Non-Target Organisms
There were some very interesting presentations at the pesticide applicators recertification course I attended last week. Half a day of the two-day course was dedicated to presentations by the Department of Fisheries and Oceans, as well as presentations by both Environment Canada and Alberta Sustainable Development. A good portion of those presentations dealt with species at risk in the province of Alberta. A lot of people have never heard of plants like the tiny Cryptanthe or the Western spiderwort but they are rare and endangered species in our province, nonetheless. Pesticide application is as much about mitigating the harm to non-target organisms as it is about controlling pests.

Science & Technology
Scouting, Be It Professional or Amateur
If you grow plants, you will have to contend with diseases at one time or another. But what is the best strategy to keep diseases at bay? I was reading the latest issue of Hortmatters from the Ontario Ministry of Agriculture that discusses how commercial tomato growers deal with diseases. From my own observations, it’s interesting to compare this information with how home gardeners typically deal with diseases. The tomato samples bought to our garden centre by home gardeners tend to have well-advanced disease problems. This is a reactive approach. Commercial growers, on the other hand, are proactive. They anticipate disease problems and utilize preventative strategies. For example, three quarters of the professional tomato growers cited in Hortmatters applied copper sprays to their transplants, and about half them also hired crop scouts to monitor crops on a regular basis.

I’m certainly not implying that home gardeners are lax in their approach to disease control. It takes a lot of training to recognize disease problems and to select the correct disease control products. Plus, I doubt any home gardener will be employing a professional scout anytime soon. I do, however, think that the important lesson to take home is that, at the very least, the habit of checking your plants once a week—before problems get out of hand—can make a huge difference. An ounce of prevention…well, you know the rest.

Hole’s has over 56 varieties of poinsettias available for the 2006 Holiday season. Jim steps you through a few of his favorites…

Quicktime
WMV

first published November 23, 20006

I don’t often have bad dreams, but when I do, I know November is here. Each year, the dreams vary somewhat, but what remains constant is their theme, which always focuses on hoards of pests attacking my poinsettia crop—a crop that requires six painstaking months of nurturing. A crop that is not recoverable if it fails.

This November, however, I am confident that I won’t have a single nightmare, and I owe my restful nights to one very tiny, some would even say handsome, little insect that goes by the Latin name Encarsia formosa. What it does, and does with deadly efficiency, is hunt down and destroy whitefly. In our modern greenhouse lexicon, Encarsia is referred to as a biocontrol. Biocontrols are the ‘good’ bugs humans employ to attack ‘bad’ bugs. The principle is simple, but the results are effective and economical. Fortunately for us, Encarsia is a biocontrol all-star. Right now, we have about 250,000 of them (give or take a few hundred) patrolling the poinsettias in the greenhouse.

See No Evil
This formidable little predatory insect is not only an extremely tiny kind of wasp (about half the size of a grain of salt), but it’s also a clandestine creature. With a quarter of a million of them casing the greenhouses, one would think they’d be relatively easy to find. But that’s not the case. It takes a sharp eye to find Encarsia, and not even our veteran staff can spot them easily. But while these demure insects avoid the limelight, they don’t shy away from the dinner table.

The encarsia are found in the tiny black dots on the card.

Once the Encarsia are released into the greenhouse, they fly to the nearest poinsettia leaf and switch to their favourite mode of transportation: walking. Encarsia meander exclusively among the hairs on the underside of the leaves and look for disk-like instars (a non-mobile, pillow-shaped young whitefly) upon which to feed. Once a suitable instar is located, the Encarsia stabs it with her ovipositor (a sharp, needle-like stinger) and begins feeding on it. After this satisfying, nutritious, high protein meal, the re-energized Encarsia searches for other instars to stab. But instead of feeding on her new prey, she inserts a single egg in her victim. The gestation period that follows is eerily reminiscent of the sequence of events from the movie Alien.

It Came From Within
If you observe the parasitized instar under a microscope, you’ll see the same grisly scene every time. As the egg develops and feeds on the entire contents of its host’s bodily fluids, it slowly transforms the instar from its normal yellowy colour to a charcoal black. When the Encarsia is fully developed, it eats a ‘lid’ off its victim’s body and escapes by squeezing itself out the opening. Wasting no time, the newly emerged Encarsia rests only a short time before flying off to find a poinsettia leaf on which to start its own search and destroy mission.

It’s interesting that of the 250,000 Encarsia roaming our greenhouses, the female to male ratio is 250,000 to 0. Simply put, male Encarsia are a colossal waste of time. They don’t have ovipositors and are, for lack of a better word, useless. While it’s true that male Encarsia exist, they are very rare, and the production of them is entirely at the female’s discretion. And forget the birds-and-the-bees lecture you received in school—female Encarsia reproduce almost entirely parthenogenetically (without fertilization), and the success of the species speaks well for the strategy. Like everything, Encarsia have their time and place. By the time the poinsettias are ready for sale, the crop is beautiful and free of whitefly and the Encarsia are long dead.

While I do sleep better knowing the whitefly instars have been stalked to extinction in our greenhouse, I must admit I am on the cusp of acquiring a whole new set of nightmares…something about exploding abdomens and a world devoid of males. I think I’ll leave the light on tonight.

Hits & Misses: Tufa-rock containers & weeding thorny cacti
Question of the Week: Do I Stop Fertilizing My Indoor Plants in Winter?
Business: Jim Goes Back to School, Again…
Science & Technology: Do Educational Gardening Programs Affect Children’s Behaviours and Attitudes?

One gardening trend that seems to be growing slowly but steadily is the ‘functional food’ movement. At one time we ate fruits and vegetables because we needed the calories to survive. Once we mastered the survival thing, we bred them to taste really good. During our age of enlightenment, we discovered that fruits and vegetables not only taste good but also were essential for our overall health. Today we’ve gone a step further and have begun breeding plants with elevated levels of specific phytochemicals that are purported to combat specific human diseases. For example, there seems to be a lot of buzz about lycopene, a phytochemical commonly found in tomatoes. Researchers are linking increased lycopene consumption to a reduction in prostate cancer and cardiovascular disease. The result is that plant breeders have developed a functional tomato called ‘Health Kick’ that has 50% more lycopene than standard tomato varieties have. Now, although we trialed Health Kick last year and I really liked the flavour of this Roma-type tomato, I find the whole high lycopene thing rather amusing. If you like Health Kick tomatoes, great. But if you want the extra lycopene and don’t want to give up your favourite tomato variety, how about just eating another half of the tomato you really like!

Hits & Misses:
Hits: A Different Kind of Container
I will make an early winter prediction that our new tufa-rock ‘planters’ will be a hot item next spring. Bob Stadnyk, our perennial department manager has some tufa rocks (a porous, extremely light rock) that are about a 30 cm tall and wide and planted with a select group of very tiny alpine plants in the rock’s crevices and hollows. The effect is reminiscent of a tropical island diorama with the rich-green moss reminding one of an island’s leeward side, while the barren side is reminiscent of the desert-like windward side. I can see these rocks as pieces of living art in the garden that will meet some customer’s demands of weed-free, very low-maintenance containers…what more could one ask for?

Misses: Rethinking Weeding Cacti
Sometimes misses can be more like cruel jokes. Take, for example, this photo of a cocky dandelion taunting me, knowing full well that I will have to give up a pint of blood to extricate it from among the three deadly Old Man cacti. Well, I didn’t lose a pint of blood when I tried to pull out the defiant dandelion, but I was stabbed repeatedly by its thorny ‘body guards’ and was forced into a temporary retreat. My new strategy to deal with a weed-infested shipment of cacti is to put on the gloves and to pull out a pair of thin needle-nose pliers—it’s slow, tedious work but the taunting must stop!

Question of the Week
Do I Stop Fertilizing My Indoor Plants in Winter?
At this time of year, I often receive indoor plant questions. One of the most popular is whether or not people should fertilize their plants over the winter months. Back in the days when our homes had smaller windows and, therefore, less light available to plants, we used to recommend not bothering to fertilize, but now that architectural styles have changed to include huge windows, that advice has changed somewhat. The increase in light levels means that some plants continue to grow all winter. The simplest answer is that if the plants are putting on growth, fertilize them at half the strength normally applied during their most active period of growth (between February and October) and apply the fertilizer half as often. Watch your plants carefully and see how they respond. If they begin to put on stretched, gangly growth, dilute the fertilizer even further and apply it less frequently.

Business
Back to School, Again
This week I will be spending a couple of days in the classroom as part of the mandatory requirements for retaining my Alberta Pesticide Applicator’s License. I have both a greenhouse and a landscape pesticide applicators license and sit on the provincial committee that oversees the approval of credit courses, but, alas, that doesn’t let me circumvent the accreditation regulations! I’m a strong advocate of continuing education, and while two days is difficult for me to fit in at this time of the year, it is important to make the time. On a related note, if you are hiring someone to apply any pesticide in your home or garden, the applicator must have the appropriate license and be a government certified applicator.

Science & Technology
Eat Your Veggies
I was reading a study from the American Society for Horticultural Science on how gardening programs affected children’s nutritional knowledge, attitudes and behaviors. The children involved in the study were in Grades 2 to 5 and were interviewed both prior to participating in the garden program and after completing the program. The outcome showed that these children significantly improved their knowledge of the benefits of eating fruit and vegetables, and, although their attitudes towards fruit and vegetables didn’t change after completing the course, most of them did make healthier choices post test. I suppose that the love of eating vegetables and (to a lesser extent) fruit, is an acquired taste. No matter how much we harp on our kids to eat their fruits and vegetables, it is the passage of time that is essential before their palates become fully engaged and they begin to enjoy the flavour. The best that we can hope for is that, at the very least, our kids eat them until their taste buds finally catch up.

A quick review of The Hole’s Dictionary of Hardy Perennials by Gerald Filipski, garden writer for the Edmonton Journal says…

General Editor Jim Hole and his perennials staff have managed to take the mystery out of buying perennials with this must-have reference for any gardener.

first published November 16, 2006

As I walked past the trial garden the other day and saw carrot tops poking out from the snow, I couldn’t help but remember Mom’s childhood stories about canning the fruits and vegetables from my grandma’s garden. Back in those days, year-round fresh produce was pure fantasy. In the winter, fruit came from a can or a jar—end of story.

Today, we’ve forgotten the concept of seasonality. We expect nothing less than year-round availability of a wide variety of perfect fruits and vegetables, and we feel annoyed if they take even a day’s hiatus from our grocery shelves. In our haste to get what we want and get out of the grocery store, few of us think about the bigger picture.

So stop and think about it. How is it possible to be spoiled with summertime vegetables during the darkest days of winter? The answer is simple—if the technology to grow the produce exists and we scream loud enough, we get what we want. When that technology doesn’t develop fast enough, desire and the siren calls of consumers are all that’s required to drive innovation—provided consumers are prepared to pay for it. But that really addresses more of the why part of the question. The how is another story.

Let There Be Light
At one time, greenhouse vegetable growers could supply the marketplace for about 10 months out of the year before surrendering to the short, low intensity sunlit days of December and January. Typically, foreign imports would fill the void during those darkest days of the year. And with good old supply-and-demand market forces coming into play, we paid a substantial premium for our insatiable desires.

Rather than cursing the imports and the dark winter months, some progressive growers have decided it’s far better to turn on the lights, literally, by installing thousands of high intensity grow lights to guarantee uninterrupted, year-round production.

As a rule of thumb, for every 1% increase in light there is a 1% increase in plant growth, up to a certain level. The amount of sunlight that tomatoes, cucumbers and peppers need to produce a good yield of fruit is about 20 moles or ‘particles’ of light per day; however, during the depths of winter, we are lucky to get about five moles. Five moles will grow some reasonably good-looking but, ultimately, fruitless plants.

Measuring Success
I remember growing greenhouse tomatoes and talking about how many pounds of fruit we could get per plant. When I talk to vegetables growers today about pounds or even kilograms of fruit per plant, they look at me like I am from the Jurassic period. The terms they use are kilograms per square meter! In other words, to be profitable, they need to know how much yield can be squeezed out of every square inch (make that centimetre) of greenhouse space.

Lighting up greenhouse vegetables isn’t cheap to do. Lights are costly to install and maintain and then there’s that thing called the power bill. But the justification for doing it is based entirely on growers gambling that our high-maintenance desires will cover their costs and leave a bit of profit in their pockets, too.
Some would argue that expecting year-round availability of fresh vegetables is yet another example of our society’s unreasonable expectations. I can’t say I agree. Like it or not, we are a consumer culture. Most of the time, there’s a lot about that to like. We don’t think it unreasonable to demand that technology provide us with a steady stream of the newest and hottest cellphones and Xboxes, so what’s overly indulgent about wanting a product that actually feeds more than our vanities? Nothing.

We recently received a note and I thought I’d post it here.

Jim,
I noticed a post of your’s some time ago about the spider website and database I maintain. Thanks for the plug! You may recall when you attended the UofA’s “All Roads Lead to U” homecoming session that I conducted an image competition for arachnids, the winners to be featured in a 2007 Canadian Arachnologist calendar. The calendar has been assembled and the images are absolutely stunning: canadianarachnology.dyndns.org/calendar. I have been trying to spread the word & have had fairly good response, but if there’s any chance you might also help spread the word, I would be forever grateful.
Cheers,
Dave

The calendar certainly has some stunning images…

And while you are there be sure to check out the stunning gallery of other spider images

Hits& Misses: ‘Cinnamon Star’ & ‘Mars Pink’ poinsettias and heat delay
Insect World: Pin-Up Spiders
The Business: Men in Trees
Science & Technology: Cole Crops

When a single tree makes the national news, it leaves little doubt as to how much trees are revered in our society. I was listening to the radio the other morning and one of the top news items was the impending removal of the chestnut tree that Anne Frank lovingly referred to in her diary. Apparently, despite efforts to save the tree, it has finally succumbed to attacks by a battalion of insect and disease pests and, therefore, must be cut down. Trees provide us with so much—shelter, shade and beauty—but sometimes we forget how much they have become an integral part of our hearts and souls.

Hits& Misses
Hits: Mixing the Old With the New
I must admit that I am still a traditionalist when it comes to poinsettias: big poinsettias with deep-red bracts and dark-green foliage are essential to decorating my home at Christmas. But once I have the prime household locations occupied by the red varieties, I always fill in the gaps with some of the newer, non-traditional varieties. This year I’m picking a couple of trial varieties that I think are outstanding. The first is ‘Cinnamon Star’, a variety with large, cinnamon-splashed bracts and exceptionally dark-green foliage. The second is a variety called ‘Mars Pink.’ It has red bracts in the centre of the flower and progressively lighter bracts as you move away from the centre. The effect is really eye-catching. Since Mars Pink is, essentially, a red, pink and white poinsettia rolled up into one, it might just satisfy both your traditionalist and your adventurous-type friends all in one sweep.

Misses: A Green Christmas
Poinsettias love warm temperatures, but they are not great fans of hot temperatures (particularly when they are trying to colour up for Christmas). When temperatures rise up into the high 20˚C range at night, poinsettias remain green rather than developing a wonderful array of coloured bracts; a condition called ‘heat delay.’ This year I have about 50 pots of a variety called ‘Sonora’ that will not colour up in time for Christmas, simply because they are a little more sensitive to heat than other poinsettia varieties and were placed too close to some heat pipes. The good news is that they account for only 50 pots out of about 40,000—but it’s still annoying. If there is anyone out there who wants-top-to-bottom green poinsettias for Christmas, I have a heck of a deal for you!

Heat is one of many factors that can cause delays in the “colouring up” process.

Insect World
Pin-Up Spiders
As you may recall from a recent addition of Jim’s Notebook, I had the opportunity to attend a lecture by David Shorthouse, a graduate student in entomology from the University of Alberta. His unbridled passion for spiders inspired him to develop a website for all things spider related http://canadianarachnology.webhop.net. Well, hot off the press for arachnophiliacs is ‘The 2007 Canadian Arachnologist Calendar,’ which features some truly outstanding photographs of some beautiful spiders. And while my daughter and I can’t wait to get a copy, I know several people at work who cringe at the thought of catching even a glimpse of the spider of the month. Hmmm…it can’t be the spider’s looks, must be the fact that they all appear nude. http://canadianarachnology.dyndns.org/calendar/

The Business
Men in Trees
Normally, we try to stick to fairly scientifically based observations about plants around here, but I couldn’t help notice a few pieces of paper floating around our coffee room the other day. They were “personality profiles” taken from the internet. Apparently you look up your birthday to see which tree is assigned to your birth date and then read up on the tree’s—and your—‘characteristics.’ Walnuts are ‘passionate,’ figs are ‘sensible’ and limes are full of ‘doubt.’ I guess it’s sort of a horticultural horoscope of types and, as is so often the case with this type of thing, if you look hard enough, you’ll eventually find something that is sort of accurate. I guess maybe Barbara Walters was on to something…

Science & Technology
Cole Crops
I was reading some research in the Journal of the American Society for Horticultural Science about cole crops. Cole crops (like broccoli, cauliflower, collard greens, cabbage, Chinese kale, kohlrabi and Brussels sprouts) are, believe or not, identical species (Brassica oleracea) that were selected over time for their various edible parts. Of all of the cole crop family members, it seems that cauliflower gets the short straw, being described as ‘undifferentiated meristem tissue.’ That doesn’t sound so bad, but the origin of the cauliflower curding trait is thought to be the result of our ancestral humans who ‘discovered a grossly mutated form’ of B. oleracea. I love cauliflower but I would adviise not discussing the ‘grossly mutated’ descriptor with your kids.

Cedars are a popular evergreen but sometimes they need a bit of extra protection in the winter to help prevent damage.

Quicktime
WMV

First published Nov.9, 2006

Einstein postulated that parallel lines eventually meet. Well, I know I don’t have the foggiest idea how he came to that conclusion, but I do have conclusive proof that he was right—that is if you’re willing to do a little reading between the lines.

Last Monday started innocently enough. I spent about an hour hunkered down at my microscope scouring the leaves of our poinsettias for insect pests. Whitefly, without question, is the number one pest of poinsettias and the bane of anyone who has tried growing them either as a hobby or professionally. Sure enough, as I finished going through the trichomes (leaf hairs) with a fine probe, I saw a few whitefly eggs nestled along the leaf veins. Cue visceral reaction: Kill pests and as quickly and efficiently as possible.

When I think of controls, the first product that comes to mind is a pesticide called permethrin. It was the pesticide of choice for many years because it could be applied safely and did an excellent job of killing whitefly. Today, however, whiteflies are resistant to permethrin, thanks to overuse, and biocontrol programs (good bugs eating bad bugs) are being employed more frequently in greenhouses, ours included. As a result, permethrin has been relegated to the back shelf.

Now flash forward to Monday evening—the evening the parallel lines started to bend slightly inward. My daughter is home from school and my wife, looking somewhat alarmed, is perusing a pamphlet on the life cycle of head lice. Apparently, lice decided to take up residence on the heads of a couple of kids from our daughter’s school. To allay parental fears and to diffuse some of the social stigmas regarding kids and, yes, “cooties,” literature was provided by both the school and Alberta Health. Most of the information focused on reassuring parents that it was a common problem, and the remainder outlined steps on how to check for lice and what “treatments” to use if you were unlucky enough to find them on your child’s head.

The parallel lines touched right about the point in the evening when I finished fishing through trichomes—I mean hairs—on my daughter’s head and read in the pamphlet that that permethrin was the product of choice for eliminating head lice. Granted, the permethrin formulated for gardens cannot be used on humans, but the topical scalp cream recommended for louse control contains exactly the same active ingredient. I probably shouldn’t have laughed, and I probably shouldn’t have told my wife, but I couldn’t resist sharing the fact that the ‘treatment’ to root out head lice was the same as the pesticide to kill whitefly that live among the hairs of poinsettia leaves. I had to be honest with her, didn’t I?

Permethrin is the chemical cousin of pyrethrum—the raw insecticide derived from the pyrethrum daisy (Chrysantemum cinerariafolium)—which explains why the Alberta Health brochure warns against using permethrin-based products if one is allergic to chrysanthemum flowers. The way the permethrin kills the lice is by disrupting the sodium ion channels in the insect’s nervous system…which is a nice way of saying it causes the lice to convulse to death.

What makes permethrin a safe product for lice control is that, although it is highly toxic to a wide range of insects, its chemical structure prevents it from easily penetrating human skin and, therefore, has relatively low human toxicity. Although I want to stress that topical lice creams are safe, in my mind, there is a good dose of irony involved in envisioning parents educating their kids on how to avoid pesticides while scrubbing permethrin into their children’s scalps.

The good news is that, according to an unofficial report from the parent underground, the head lice have been defeated, and parents can return to worrying about what is getting into kids heads rather than what’s residing on them.

I suppose I should also take the time to apologize to Einstein for the tenuous link between theorems and “cooties”—but you have to admit that both are likely to cause a lot of head scratching.