First Published 2/24/2005
Variegation

As humans, part of our evolutionary heritage is to see beauty in patterns; that’s why variegated plants, with their zones of cream or white stripes on green leaves, are among the most highly prized. Though variegated plants are a relatively common sight at garden centres, occasionally gardeners may notice that a normally unvariegated plant in their garden suddenly develops variegation on one or more leaves or flowers. When confronted with this unfamiliar sight, some gardeners wonder how the heck it happened, while others wonder – some with hope, some with dread – if the change is permanent.

Beautiful Mutations

So how do plants that start their lives as normally green-leaved plants suddenly develop white stripes on the leaf margins? Strangely enough, variegation often starts off as one microscopic plant cell getting its genetic information a little mixed up and then growing and multiplying, producing a succession of cells carrying the same misinformation as the original wayward cell. It’s been estimated that something like one in every 500,000 cells produces a mutation spontaneously. Usually the mutation is lethal and the cell simply dies, but rarely the cell survives and replicates, reproducing the mutation right along with its normal characteristics. This is how variegated flowers and foliage come into being.

Not all mutations produce attractive results. The next time you shop in the produce section of your grocery store, have a look at a variety of different fruits and vegetables. If you’re lucky (or, rather, unlucky) you may find a few that look a little strange. I’ve seen navel oranges, for example, that look like half of a smaller orange has been “welded” onto a larger orange half; in other words, a round orange with a thick skin on one half of the sphere and a much thinner skin on the other half. This is the fruit equivalent of variegation on a leaf.

Variegation Vexation

Although it’s rare to find these variegations popping up in your existing, previously non-variegated garden plants, it does happen. (Plant breeders, who propagate millions of plants every year, have a much better chance of discovering spontaneous variegation.) However, even if variegation occurs on your plants, that variegation may not be stable – that is, the new colouration may last only the length of the season in which it originally appears. The following year, the plant may revert back to its original colour. (Sometimes, even variegated varieties purchased at a greenhouse may revert to a non-variegated state after a few years, much to the consternation of the gardener!)

Stability of variegated plants has a lot to do with where the variegation itself originated in the plant. Mutations that originated in a specific layer of cells in the growing point have the greatest chance of producing stable offspring for years to come, but if the mutation originated outside of this layer, the chances of that mutation remaining stable are far slimmer.

Not Universally Popular

Of course, some gardeners would be relieved if a spontaneous variegation went away on its own. I find it interesting that a few gardening purists consider variegated plants to be abominations, unworthy of inclusion in the garden because they deviate from the norm. But in reality, every single species of plant in the world owes its existence to a string of mutations that occurred over the eons. Variegation is just one more variation, and one that I feel makes gardening so rewarding.

First Published 2/17/2005
Earthworms

Earthworms have a reputation as the quintessential guardians of soil health. Some people even become alarmed if they can’t find earthworms in their soil. But while earthworms are excellent stewards of Canadian soils, the truth is they are no more natural to the Canadian landscape than are elephants or zebras.

The Newcomers

There is some speculation that earthworms lived in Canada in ages past, but even if they had, the glacial ice sheets left a 15,000 year earthworm void throughout nearly every corner of our country. The earthworms that we see now are European invaders, brought to Canada inadvertently by early settlers; the worms were stowaways on the plants the settlers brought with them.

Since the Canadian prairies have had rich, deep, fertile soil for thousands of years, it begs the question: are earthworms really necessary today?

Well, settlers came to the prairies, turned the virgin soils and grew excellent crops sans earthworms. But virtually all of the soils across the prairies today have been plowed, hoed, moved, compacted and otherwise disturbed, which has, without question, had a negative impact on the quality of our soils. Earthworms can’t repair all of the damage, but they can improve the soil by chewing their way through the problem, so to speak.

Aristotle once called earthworms “the intestines of the soil,” and no wonder; they ingest decaying leaves and roots, as well as numerous soil microorganisms, consuming about one third of their own bodyweight per day. The rich “castings,” a fancy name for excrement, provide a fine array of nutrients for absorption by plant roots. Earthworms are also great mixers, moving and blending the castings throughout the soil profile. The tunneling action of the worms leaves excellent hollows for movement of water and air into the soil.

So perhaps earthworms aren’t strictly “necessary,” but there’s no question that they have a positive effect on modern soils.

The Dark Worms

Some earthworms can be a little annoying at times. One species – the dew worm, Lumbricus terrestris – has an affinity for lawns. Dew worms are also known as nightcrawlers, because they often crawl to the surface at night, pulling fallen leaves into their burrows and leaving large, unsightly mounds of soil in the lawn surface. This is largely a cosmetic problem, although the mounds can become rather annoying when one is trying to mow. Pesticides such as carbaryl are registered for dew worm control, but they’re not particularly effective. The best one can expect is a reduction in worm population – not elimination. Even worse, carbaryl application can destroy many beneficial lawn insects, including ground beetles and big-eyed bugs, which are predators of many garden insect pests. If I had dew worms, I’d just live with them.

As the Worm Turns

Beneficial or not, earthworms have settled into the soils of prairie yards for good. While I wouldn’t go out of my way to add worms to the soil, nor would I go to any trouble to root them out; as far as worms are concerned, I say let them burrow to their hearts’ content.

First Published 2/10/2005
Valentine’s Day Bouquets

Valentine’s Day is just around the corner, and the heart rates of millions of men (and increasing numbers of women) are jumping, perhaps as the result of unbridled passion for their partners…or perhaps because of unbridled panic over what to buy. Red roses have become ingrained in our minds as the consummate Valentine’s Day flower, so much so that any other choice may seem foolhardy. But how many of us have actually asked our significant other if roses are really the best choice?

Popping the Question

Just a few days ago, I conducted a short, very unscientific survey, including my wife and some of my female colleagues. I asked “If you were to receive a gift of flowers for Valentine’s Day, would you prefer red roses or something else?”

The results weren’t shocking, but they were a little surprising. About 10% of the women that I talked to wanted roses for Valentine’s Day, yet of that 10% only a small fraction thought specifically red roses were the perfect gift. Pink and yellow roses actually topped the list among rose lovers, rather than the traditional red. Spring flowers such as tulips and daffodils and mixed spring-flowering plants in a bouquet were more popular choices by far. Even potted orchids finished higher than red roses!

“So what’s wrong with red roses?” was my follow-up question. Some claimed that you’ve got to be in your teens to appreciate them, while others said that roses were unimaginative, that they required too little thought. Does this mean that time transforms the raging flames of love into a flickering pilot light? I don’t believe so. It seems to me that no matter how beautiful a plant may be – and let’s face it, for sheer pulchritude, a fine red rose is tough to beat – after receiving it for ten or twenty years, it’s going to get a little stale. (On the other hand, one woman did remark that receiving anything but red roses on Valentine’s Day was “unthinkable!”)

Preserving Your Sentiments

No matter what kind of bouquet you’re considering for the big day, to keep those romantic feelings warm, you’ve got to keep the flowers cool. The longer you can keep a bouquet in a cool spot, out of direct sunlight, the longer it will last. And don’t forget to add that packet of floral preservative to the water when you fill the vase; the florist included it with the bouquet for a very good reason. The acid and other compounds in the preservative will reduce bacterial growth. Bacteria can multiply rapidly in untreated water, plugging the flowers’ stems and preventing them from absorbing water; the floral preservative slows down this process. Distilled and deionized water is better than tap water, extending shelf life by a day or two, but you’ll have to decide if the pricier water is worth those extra days. (On the other hand, how can you put a price on love?)

Also remember that high quality flowers last a lot longer than those that are on their last legs when you purchase them. If all the petals on a bouquet fall off on the big day, the straggly-looking bunch of half-dead sticks that remains is probably going to dampen the romantic mood a little.

Say it With Flowers…of Some Kind

Books, movies, advertisements and tradition have an overpowering effect on a guy’s purchasing decision, even if his significant other would rather receive something a little more imaginative. So without a doubt, red roses will remain the most popular flower this Valentine’s Day, and for many more to come.

On the other hand, I think most women – no, most people – are happy to receive any kind of flower, even a bouquet of red roses…anytime, anywhere, and for any reason.

First Published 2/3/2005
The Uncanny Canna

For several years now, I’ve grown canna lilies, both inside my home and outside on the back deck. In fact, they’re probably my favourite tropical plant – not just because of their beauty, but because I respect their resilience and am fascinated by their colourful history.

The Cannas in my Basement

Cannas are tall, showy plants; they belong to the Cannaceae family, which also includes ginger, bananas, and bird-of-paradise, among others. Canna lilies have broad, long, often colourful leaves surrounding tall spikes of brilliant, gladiolus-like flowers. Cannas provide an exotic, tropical feel to gardens and because many varieties are quite large, they make excellent centerpieces in flowerbeds and pots. I’ve had one growing in a container in my solarium for some time now, and it easily reaches heights of eight feet.

Although cannas are not winter hardy, the roots are very tough, so each fall I unceremoniously rip them from their container, toss them into a smaller, empty pot, and leave them in a corner of my basement. I throw a little bit of soil over the woody rhizomes, then ignore them, save for watering them a couple of times during the winter. And yet, despite this very minimalist care regimen, new, vigorous shoots have always poked out of the soil each winter, anxious to get the spring season started; in fact, they’re showing themselves right now. I’ll just keep them cool, giving them enough water to keep them alive, but not quite enough to stimulate a lot of new growth.

Not Your Average Ornamental

Cannas have an interesting lineage. There are nine species of cannas, all native to the new world. Over the years, cannas have undergone intensive breeding and hybridization, and as a result most garden varieties are called Canna x generalis in Latin, a name that alludes to this extensive mixing of species, mixing that has led to dozens of incredible varieties in all kinds of colours and textures.

Not only are cannas gorgeous and easy to grow, they have a quirky, fascinating history. One canna species, Canna indica, is also known as Indian Shot Plant, a name partly derived from the mistaken belief that the plant originated in India, and partly due to the fact that the seeds have been used as a substitute for ammunition! The hard black seeds are so tough that when fired from a shotgun, they can penetrate wood to a depth of several millimetres, with many of the seeds remaining undamaged by the impact. (Naturally, I don’t recommend trying this experiment at home.)

In some South American countries, the seeds are used for an entirely different purpose: as jewelry. The seeds are not only very hard, but also shiny and pearl-like. They make excellent beads for necklaces, bracelets and the like.

The people of South America make good use of another species, Canna edulis (also known as Queensland Arrowroot). They harvest the rhizomes of this canna for their starchy roots, which are ground into flour and used for cooking. In Vietnam, the rhizomes are quite commonly used as animal feed.

Canna Caution

If you’re planning on growing cannas this year, you should be aware of one potential problem: thanks to their growing popularity, extensive shipping and handling around the world has exposed many of the rhizomes and plants to a few viral diseases. The viruses usually manifest themselves when the cannas are about 15-30 cm tall, and they quickly leave the plant brown and stunted. There is no cure for these viral diseases, and disposal of any infected plants is the only solution. (Fortunately, the virus doesn’t spread to other garden plants.) The problem is sporadic, so it shouldn’t prevent you from considering cannas, but it doesn’t hurt to be vigilant; buying cannas from trusted, reputable suppliers is the best way to reduce your risk of encountering this problem.

My favourite plants are those which combine beauty, toughness and an interesting history. Cannas have all these qualities in spades, and with their ability to withstand my rough handling, they’ll always have a place in my garden.