Posted by admin to Current Articles on 2007-08-15, 11:37:32

First published August 9, 2007

Summer is the time when I load up on spinach salads. Toss in a few berries, almonds and a vinaigrette dressing and you pretty much have the perfect summertime meal. But even though I love my spinach salads, each and every one of them is always slightly tainted—and in more ways than one.

Lasting impressions
Back in my university days, one of my horticulture professors casually mentioned to our class that spinach manufactures oxalic acid—the same acid used to clean wood on decks and to remove rust stains from sinks. Not what I wanted to hear—and it got worse. It seemed spoiling spinach for me wasn’t enough of a day’s work for my proff, so he sent in the other shoe: oxalic acid, he said, reacted with calcium, forming an indigestible compound called calcium oxalate. Well FANtastic. Not only would I never again be able to eat a spinach salad without thinking about acid scrubbing my insides, I would also never be able to wash it down with a glass of milk without rendering my favourite drink nutritionally useless. Wood cleaner? Milk destroyer? That lecture sounded like blasphemy to a kid growing up on a vegetable farm. Hadn’t they heard? Vegetables were supposed to be the panacea for human health.

My professor, of course, was really just trying to show the complexities of the science of food crops—trying to get our young impressionable minds to see a little grey in our black and white worlds. It worked.

I soon learned that oxalic acid was but one of many toxins that plants can manufacture—toxins that every garden vegetable contains but that we don’t worry about because they occur only in trace amounts. If we were to concentrate and consume these toxins, however, there’d be a problem. Think of it in terms of caffeine. Reasonable daily amounts are acceptable, but downing dozens of espressos in a row will put you on the wrong side of the turf. The point is, we eat a whole host of vegetables and fruits that contain natural plant chemicals—some good for us; some not so good if consumed in high concentrations. The bigger point is that, over many millennia, our bodies have learned to evolve and deal with these toxins, which is exactly why the good stuff in spinach far outweighs the bad.

What doesn’t kill you…
Want to make the whole toxin issue even more complex? Then have a look at the emerging “science” of hormesis. Hormesis (from Greek hormaein, meaning “to excite”) is a term used to describe the generally favourable biological response that trace doses of certain toxins have on people. Poison!—good for us? Well, let’s just say hormesis is a contentious science. But for arguments sake, what would happen if we removed all the naturally occurring toxins from our vegetables? Would we be healthier or worse off? It’s a great question that doesn’t have a good answer, at least not yet. But suffice to say that every time we try to dissect foods and pull out only the components we believe to be essential for human health, we find out that food is a lot more complex than we first thought. Whole grain bread, for example, was “improved” to white bread before we returned to whole grain. Who knows; hormesis may not be as counterintuitive as it initially seems. Perhaps one day we’ll even have to call for a retrial of some convicted chemicals, or, at the very least, give them a lighter sentence.

As yet, I can’t say that I’ve come across any research that links low doses of oxalic acid or any other “bad” plant chemical to hormesis-like effects. Perhaps a tiny dose of a certain plant poison would put our bodies on red alert—sort of comparable to the effects of an immunization shot. I don’t know. At the same time, I am sure that a number of scientists are trying to answer the questions regarding the pros and cons of naturally occurring chemicals in our vegetables. Whether you’re a skeptic or a believer, it is pretty fascinating to find out that the very same spinach that transformed Popeye into a human dynamo could clean the poop deck as well.

Posted by admin to Current Articles on 2007-08-10, 13:47:48

first published August 2, 2007

Old versus new. Conformists versus rogues. Heirlooms versus hybrids. When it comes to choosing sides in the tomato patch, the battle lines are clearly drawn. As for my own allegiance, it’s evolving. When I was a kid growing up on the farm, my brother and our friends didn’t care about the culinary aspects of heirlooms or hybrids. We just hoped for a hot summer so that there’d be plenty of overripe fruit for tomato fights. Personally, I always found that the best tomato was neither heirloom nor hybrid—it was the one that left the biggest splash mark on the back of my friend’s head. Now that I’ve matured, somewhat, I appreciate their differences. As for declaring which is better…

The first thing to realize is that more unites the two types of tomatoes than divides them. Both heirlooms and hybrids are descendants of some tough and not particularly palatable tomato species that evolved in Peru. But thanks, in part, to the indigenous people of South America and their countless selections of superior tomato plants, we now have a flavourful fruit that’s enjoyed—and argued about—worldwide. Interestingly enough, over those many years of selecting ‘perfect’ tomatoes, we somewhat inadvertently chose varieties with short styles (the long tubes that stick out the ends of flowers and hold up the sticky, pollen-grabbing stigma). Because the short styles tend to keep the stigmas hidden from tomato-pollinating creatures, like bees, our modern tomato varieties (heirlooms and hybrids) are largely self-pollinated, which was not the case with the original Peruvian species.

So what does this have to do with heirlooms and hybrids? Well, heirloom tomatoes became heirlooms because they are almost entirely self-pollinated, meaning their seed can be kept true and the traits of the fruit can be passed down to each successive generation. But make no mistake; merely remaining “true” isn’t enough to earn the title heirloom. Although the definition is somewhat of a moving target, it’s generally agreed that heirloom varieties are those that can claim to have been around for at least 40–50 years. Over the course of those many generations, errant pollen will occasionally sneak through and an entirely new tomato variety will result, but as long as seeds from those rogues aren’t collected, the cherished heirloom variety retains its high degree of uniformity, as well as its reputation.

It takes two
Hybrids, on the other hand, live by different rules and stake their claim to superiority by taking the best traits from at least two parents. By crossing varieties, offspring can be selected to have a particular shape, size and colour, as well as a high yield and resistance to disease. To attain this consistency, the crossing must be controlled through hand pollination and the original cross must be repeated each season. If seed is simply saved and planted from year to year (like heirloom seeds are), the varieties will slowly segregate and revert to various parental forms. So, for example, if two heirlooms were chosen for hybrid production, each heirloom variety would be carefully inbred for generations to get a highly uniform population with specific traits. Once the two varieties were cross-pollinated, the resulting seed would be highly uniform with next to no rogue plants. However (and it’s a big however), if you were to collect and grow the resulting seeds in your yard, you’d eventually lose the original uniformity of the fruit. Without getting into plant genetics, the tomatoes would look like a rogue’s gallery of tomato varieties: some good, some mediocre.

You say tomato
So what does this all mean when it comes to taste? Well, I hate to come out in the middle, but I don’t think there’s a lot of difference between the best tasting heirlooms and the best tasting hybrids. So take your pick and let aesthetics sway you. In one corner, you have the pretty boy hybrids with perfectly smooth skin and uniform size. In the other, you have the heavily ribbed, and uniquely colourful heirlooms. Everything after that is just a matter of taste.

Posted by admin to Current Articles on 2007-08-02, 13:53:31

first published July 19, 2007

When I walk around the city of Edmonton and see all the construction going on, I can’t help but agree that the crane seems to be replacing the great horned owl as Alberta’s provincial bird. And although I’m all for progress and what it affords us, I’m more than a little worried about what it costs the street and boulevard trees that live near the nesting sites of these gargantuan metal birds.

At first glance, the large street trees on the periphery of construction sites might not seem worse for wear, but that’s all too often a case of perception versus reality. Many of those trees are dying. And although some of the loss has to do with drought and pests, most of it has to do with us—and I mean all of us. Public trees are the public’s responsibility, yet we often fail to demand that they receive adequate protection during construction. It seems like second nature to criticize city officials when our tires smack into potholes, but we are not so quick to complain when construction tires meet roots and trunks. So how can we create awareness and protect our trees from construction damage? Well, to start, perhaps for every sign that reads, Caution: Construction Zone, there should be an accompanying sign that reads, Caution: Root Zone.

Burial ground
The root zone around a tree should be thought of as sacred. Ideally, no heavy traffic nor equipment should come near it, but I’d be willing to concede an equipment-free zone that is four times the diameter of the tree’s trunk. Unfortunately, that zone is often prime real estate under which to store equipment, drop construction shacks and locate port-a-potties. From a tree’s perspective, you couldn’t choose a worse location. There are, of course, construction companies that are exemplary in protecting trees by placing shrouding around trunks and staying well away from root zones, but that tends to be the exception rather than the rule. So what difference does it really make to a tree’s health? Well, a lot.

Out of sight; out of mind
Roots need plenty of oxygen, a consistent supply of water and nutrients, and a surprisingly large amount of physical space in which to grow. When a tree is subjected to a short supply of any one of those requirements, it either dies outright or struggles for a few years before facing a premature death. Heavy equipment twisting and turning beneath a tree’s canopy relentlessly compacts the soil around the root zone and writes the script for its fate. It’s hard to come up with a comparison, but if trees were human, their compacted roots would go through the equivalent of what lungs endure when there’s something heavy on your chest—think back to the days when wrestling with a sibling usually ended with being pinned down and having an older brother sit on your chest (but I’m not bitter…).

When the soil isn’t porous enough to allow air to infiltrate properly, the entire tree suffers. Roots work in harmony with the leaves, nurturing each other, so what’s bad for one, becomes very bad for the other—when tree roots die, so do the leaves and, eventually, so does the entire tree. Unfortunately, because that initial damage is out of sight and out of mind, the consequences of those actions are never fully felt by those who are responsible.

Living treasures
The same safe practices should apply to construction zones in our own yards. If you choose to build your home near a tree that you love, make sure you put the time and effort into taking precautions. So often I see people building decks around trees they love, but because they didn’t understand the needs of the root zone, ended up destroying the very thing they were trying to save.

Perhaps, the best way to preserve our stately trees is to redefine them—to think of them as living antiques. I mean, just think about how much admiration and respect we have for antique furniture and antique cars. A hundred-year-old maple planted by a generation that came before us deserves at least as much respect as say a hundred-year-old maple vanity. And I suppose if it doesn’t, the vanity is all ours.

Posted by admin to Current Articles on 2007-07-27, 08:49:16

first published July 19, 2007

I’m always being asked “What’s the biggest challenge that gardeners face?” Is it bugs? Weeds? Frost? Maybe, but for many gardeners, it’s summer vacations. More accurately, figuring out how to enjoy that well-deserved getaway without worrying about returning to a moonscape.

If you’re lucky enough to have a skilled, dedicated and willing friend or neighbour to water your plants, you’re set. Go ahead and relax knowing that your garden will not only survive but also thrive while you’re away. The rest of us will try to be happy for you.

So what are the options? Are plants capable of fending for themselves in your absence? Well, theoretically, they could, but you’d have to be a hard-core gambler to believe in the odds of having the perfect script: sunny, calm days, followed by just the right amount of rain at night, followed by all the planets aligning. Fortunately, there are ways of shifting the odds in your garden’s favour. The good news is none of them involve keeping your vacation short.

Loath to leave
If you are a regular summer vacationer and gardener, your best bet is to grow drought-tolerant plants. With all the spectacular new varieties of grasses and succulents hitting the market, there just no reason not to. I wouldn’t be without my succulent containers. They look great, and to date, I’ve watered them only once, which had more to do with a need for fertilizer than it did with a need for moisture. Would I feel completely comfortable leaving them to fend for themselves? Absolutely.

If drought-tolerant plants aren’t your style but water-loving annuals are, consider growing them in containers that can be easily moved to a shady spot of the yard (not deep shade). Less sun means less evapotranspiration (the loss of moisture through a plant’s foliage and from the soil’s surface). You can’t eliminate evapotranspiration, but you can certainly slow it down by doing a little planning, starting with choosing as big a pot as possible—they hold a large volume of soil and, therefore, a large volume of water. Adding saucers to those pots will also provide a little water reserve. The only catch to that is hoping you don’t get a rainy spell. If you do, the pots won’t be able to drain properly and the soil could become waterlogged.

To prepare the rest of your garden, consider applying a layer of mulch. It will reduce moisture loss through the soil surface and keep roots cool and moist. The optimum depth for mulch usually ranges between 5 and 10 cm. Just be sure to keep it away from the bases of plans to avoid problems with rot. If you’ve recently transplanted some trees, invest in “water bags.” They’re giant water-filled, doughnut-shaped bladders that allow water to trickle into the tree’s root zone. Just keep remember that water bags are an aid—not a replacement—for good watering practices.

Still sound like too much work? Then maybe automatic irrigation systems are more your speed. With a combination of timers, sprinklers and drippers, it’s possible to have every plant in your yard automatically irrigated on a regular schedule. The cost is quite reasonable, but I don’t like the idea of trusting a timer to turn on when it’s supposed to. Actually, it’s not the turning on that worries me as much as it is the turning off. Between occasional accidents and unnecessary prescheduled waterings, automatic irrigation systems can waste a lot of water. A good compromise is to give everything a good soaking before you leave and to have someone you trust turn your irrigation system on and off as needed.

Home again, Home again
So you gave it your best. You planned ahead. You put your pots in the shade. You asked your neighbour to water. You still can home to wilted plants. What then? Well, start by watering—and quickly. Immerse hanging baskets and small containers in a kiddy pool, give the larger ones a good drink from the water barrel and then focus your attention on finding the perfect spot in the house for the thank-you gift you were going to give your neighbour.

Posted by admin to Current Articles on 2007-07-20, 06:30:02

first published July 5, 2007

If you were to name the most hated of garden pests, it would have to be the lowly slug. After all, can you name another pest that’s inspired as many gruesome methods of execution? They’ve been melted with table salt, squashed beneath sheets of plywood, electrocuted by copper, hunted with flashlights, left to roast in the sun and even drown in beer (what a waste!—of beer, that is). So what gives? Why do we hate these guys so much?

To hazard a guess, I’d say the hatred goes well beyond disliking that slugs feast on our hostas and lettuce and has a lot to do with feeling that that any creature that’s slimy, gooey and hides in our gardens is reprehensible and deserving of our “no punishment is too good” stance. Now, having said that, I don’t really want to be the guy who defends slugs, but (and it’s a big but) I can’t deny that they’re rather fascinating in their own right.

Know your enemy
Here on the prairies, we really have only one species of slug to worry about, the grey garden slug (Deroceras reticulatum). It’s a rather nondescript, milky-grey little slug that gardeners on the West Coast laugh at when they compare it to the monstrous species they have. Still, our slugs manage to do a respectable job of eating about 40 per cent of their body weight a day. If you want that quantified a bit more accurately, slugs will chew through about 2 square centimetres (or about 60 milligrams) of plant tissue per day and will travel about 90 centimetres a day to get it done.

A complicated kindness
The most fascinating and bizarre aspect of a slug’s life is—without question—its sex life. Slugs are hermaphrodites, meaning they are equipped with both male and female reproductive organs. And although they prefer to mate with another slug, they aren’t bashful about getting the job done on their own when no other slug is around. Now, if you’re thinking about tossing around a smidge of judgement, I suggest you hold on to it for another second—you’ll want to save it for when I tell you about the sex life of the banana slug. It’s mating routine is…well…voracious and often concludes with a little something called apophallation—the chewing off of penises. Apparently, it’s Nature’s way of maintaining the species. The apophallated slug doesn’t die (although I suspect it wishes it could) but instead is forced to become female, thus increasing both egg production and the odds of reproductive success. Fascinating!—but I think I’ll pass.

Now that you know how slugs reproduce, here’s what you need to know to keep them from excelling at it in your yard. Whenever possible, choose slug-resistant plants, such as hard-leaved evergreens, bleeding hearts, ferns and foxgloves. If hostas are your thing, think blue at planting time: slugs love hostas, but they like blue ones the least. Recruiting some help is never a bad idea, either, so when you see those creepy, large, black beetles that scurry around your yard, don’t stomp them out; they love nothing more than to make a meal out of a slug. There are other more attractive predators that would be happy to eat slugs for you, but a front yard full of chickens or snakes has its own set of consequences. One last factor to consider is your soil. Avoid over-watering, and keep bare soil well cultivated—the best way to get rid of slug eggs it to destroy them before they hatch.

So there you have it: a much-too-personal glimpse into the secret lives of slugs. Hopefully knowing a little more about them will inspire in you an unlikely appreciation for what they endure to make your lives difficult. However, if you still feel a need for the visceral satisfaction of watching slugs die, there is no limit to the execution methods you can employ. Just remember, if you ever find yourself growing plants to attract slugs so that you can devise new ways to destroy these slimy pests…you might want to consider a new hobby.

Posted by admin to Current Articles on 2007-07-13, 07:00:41

first published July 5, 2007

What do you do when you fall in love with a plant because it’s a bit weird and quirky and then, one day, it decides to abandon its wanton ways in pursuit of a life of conformity? Well, that’s exactly what you have to ask yourself when dealing with a group of plants I like to think of as Nature’s aberrations—plants otherwise known as variegated.

Love losta
To explain how variegation is lost, it first helps to understand that variegation is caused by a lack of chlorophyll and other pigments in a section of plant tissue. Typically, that abnormality is expressed as a rebellious pattern on leaves or flowers. The mutation itself isn’t serious enough to be lethal but will cause many variegated plants to have a little less vigour than their non-variegated relatives, especially in the wild. Fortunately, the vast majority of gardeners are more than happy to sacrifice a bit of vigour for a whole lot of variegation.

To satisfy our weakness for variegation, plant breeders and propagators keep a close eye out for plants that display unusual patterns. But before a variegated plant can make its way to the marketplace, it must first demonstrate a high level of stability. And what that means—at the risk of sounding a bit oxymoronic (or the other kind)—is that the variegated plant must exhibit a convincing amount of stable weirdness.

Emerging threats of normalcy
Understanding all the science behind variegation is quite complicated, so here is the nutshell version. For variegation to be stable, the variegation trait must be caused by a mutated cell or a group of cells that are fit enough to grow and multiply, and those cells must originate in a region of the plant where they are involved in generating new variegated gene cells. For example, if the mutation originates in a section of a leaf or stem where normal tissue can outgrow the mutation, the variegation pattern will often be unstable and disappear. However, when there is an “island” of mutated cells within a growing point or tip, the variegation has a greater chance of being stable. A good example of a stable mutation is the ‘Ruby Red’ grapefruit. It began its life as a weird grapefruit branch and grew into an all-star fruit tree. Not bad for a mutant.

Of course, to every set of rules there are always exceptions, which is why it’s quite common for completely stable varieties of plants to lose their patterns over time. And that’s exactly what happens with some variegated euonymous shrubs when the “normal” buds produce leaves that have more chlorophyll than the variegated leaves have. Having more chlorophyll allows the normal leaves to grow faster and to out compete the variegated foliage. In this case, the solution to preserving variegation is to get out the pruners and to lop off the emerging threat of normalcy. Variegated lilacs can be treated similarly when they develop “normal” shoots: unless these shoots are removed, the lilac will revert back to its natural non-variegated state.

Lost variegation can also be the result of a plant growing in the wrong light environment. Indoor plants such as Dracaena ‘Warneckii’ will lose their characteristic white band of tissue at their leaf margins when grown in light levels that are too high. But place that same dracaena in a spot that receives less light, and the striking variegation will return.

So if you find that your favourite plant is gradually losing its flamboyant edge, you hopefully now have a few means of defense against factors that threaten to dominate your cherished mutants.

On the other hand, you could just accept the fact that variegation is merely an ephemeral phase in your plant’s life. You know, kind of like in college when you indulge a brief phase of anarchy before inevitably settling into conformity and suburbia, complete with a family and a dog. Hmmm…perhaps the compromise is insisting that the dog at least have spots.

Posted by admin to Current Articles on 2007-07-06, 09:57:43

first published June 28, 2007

One of my most enjoyable walks in June is the one I take from the office to the greenhouses. Some of that enjoyment is definitely derived from the glee of escaping the writer’s block at my desk, but the majority of the pleasure is a direct result of walking by a 10-metre-long hedge of dwarf Korean lilacs that unapologetically overwhelms my senses. Yet, as fragrant and colourful as lilacs are, they have another outstanding characteristic that we tend to forget about: versatility.

Dwarf Korean Lilac

The heart grows fonder
One of the many things that make lilacs so versatile is their ability to adapt to a variety of environments. They are extremely cold hardy, perform well in full sun or light shade and withstand drought remarkably well. And if that’s not enough, there are also a large number of cultivars with a wide array of growth habits to suit the needs of the most discerning of gardeners.

If it’s a hedge you need, it’s tough to beat the dwarf Korean lilac. Its reddish-purple flowerbuds open to a wonderful pinkish purple during the first or second week of June and produce a massive display of sweetly scented blooms. The maintenance of this shrub also tends to be minimal. It can be pruned and shaped to a particular form without a lot of fuss, and it stays compact, growing to a height of 1–2 metres. Just remember not to use a mulch around your dwarf Korean lilac. Normally, this variety won’t sucker, but a heavy layer of mulch will encourage it to act otherwise.

If a hedge isn’t your style, try a Japanese tree lilac. One of my favourites is the variety ‘Ivory Silk.’ It can get up to about 10 metres wide and tall (although most of the ones I’ve seen are about half that height) and produces creamy flower clusters that are about 10–20 cm in length. One of the nicest things about this variety it that it will be in full bloom long after other lilacs are past their flowering prime. Its oval shape and reddish-brown bark also make it stand out in a crowd.

If heavy masses of pink, double flowers on 25-cm-long clusters pique your interest, you can’t go wrong with ‘Beauty of Moscow.’ Lilac experts place this variety high on the Best-Of List. This upright shrub reaches a maximum width of 2–3 metres (which is slightly narrower than other French hybrid lilacs) and grows to a height of 8–10 metres. It serves equally well as an excellent screening plant or as a feature shrub.

Care & Maintenance
There aren’t a lot of tricks to growing great looking lilacs. They will grow in some pretty lean soils, but if you want to produce the largest number of high quality blooms, give them plenty of rich soil and a sunny location. The only real downside to planting in full sun is that the blooms tend to fade quickly during hot spells. A good watering once a week won’t eliminate fading but will increase the longevity of the flowers. The most important rule to remember when dealing with lilacs is that the blooms should be pruned only after the flowers have faded and turned brown and should never be pruned too severely; otherwise you run the risk of shearing off the flowerbuds that become next year’s blooms. This doesn’t mean you can’t cut flowers for bouquets—you can; selectively removing a few bouquet’s worth of branches won’t cause any problems.

The last thing to consider in terms of maintenance is how to deal with suckering. It’s something that everyone seems to hate dealing with, but I think it gets a bit of a bad rap. Most of the lilac varieties that I’ve seen (especially newer varieties) don’t produce a lot of suckers, and those that do can be brought under control with a few snips.

So get outside and find the perfect spot to plant a lilac you can enjoy and be overwhelmed by. After all, of all the human senses, the sense of smell is purported to be the most powerful for stimulating vivid memories. Apparently, they are also not too bad for unlocking writer’s block.