Of Bulbs, Bugs, & Below Zero: Frozen in an Alien Landscape

Today is Canadian Thanksgiving and we are into our fifth day of subzero (Celsius) temperatures and snow in this Zone 3 Home Bug Garden. I’ve only been keeping good temperature records since 2005, but weather this cold (it hasn’t been above -2 C since last Wednesday) is unprecedented in my Garden Journal. It’s not the earliest for snow (that was 9 September 2004), but I'm afraid that 5 consecutive days below zero means that is it for the bugs and flowers this year and all I’ll have in store for this blog is dreams of bug gardens past. I left out the last of the Rainbow Swiss Chard, because it is supposed to be cold hardy. We will see.

The chard had a hard time this summer, with lots of beet leaf miners, probably Pegomya hyoscyami (Panzer). We may have pictures of the adults, but they are indistinguishable from the numerous other small grey flies in the Home Bug Garden fauna. The small white eggs are laid on the underside of leaves and the maggots penetrate the leaf, feed between the two surfaces of the leaf, and cause large brown blotches. At first I thought they were interesting, but several generations later, I hate them. There’s no chemical control for home owners, but crushing their eggs can feel rewarding, in an impotent, chemical-free way. Picking and destroying the older, outside leaves preferred by the flies is also recommended, but seems to have no effect– the neighbourhood seems to have a large endemic population of the flies, probably from many years of people growing beets and ignoring the blotches.

Well, so much for the flies, back to this cold, nasty weather – is it unprecedented? As a conservative check on just how unusual a long freeze in early October is, I went to the Environment Canada website and the Edmonton City Centre Airport and their Climate Data Online button. It is a bit complicated and unintuitive, but eventually I was able to find the monthly reports that included maximum and minimum temperatures for downtown Edmonton going back to 1937 (Edmonton City Centre AWOS [2009-2005], A (2005-1937]). You have to go back 50 years, to 1959, to find another stretch of 5 days with below zero maximum temperatures in the first half of October (and then again in 1957) – so very unusual, but not unprecedented. Below freezing daily highs are more common in the second half of October (e.g. in 2004 – the year of the 5 cm snowfall on September 9), but above freezing and even relatively warm temperatures are more the norm.

The City Centre Airport shows a distinct Urban Heat Island Effect (UHI) compared to my backyard records and is usually another several degrees warmer at night than the International Airport (records to 1961) in the countryside south of town. However, a long stretch of subzero days in the first half of October is unprecedented in the last 48 years at the International Airport (which opened in 1960 - presumably the fields where the airport would be in 1959 would have had the same cold stretch as Downtown in 1959). So, why all this harping on cold? Well, the ground is frozen and I’m still waiting for my Dutch Spring bulb order!

One could argue that a Home Bug Gardener would be better planting native, rather than exotic bulbs. After all aren’t native plants good and alien plants bad (or at least suspect)? Alas, the native-alien divide is one of those twilight zones where the science becomes gray and shadowed by politics and beliefs trump facts. My Australian instilled aversion to invaders is still trying to come to grips with Alberta’s recently deglaciated landscape awash with relatively recent invaders. But whichever side of the invasive species controversy I eventually come down on, science or xenophobia, I know that after the long nasty winters here, I need some cheerful flowers as early in the Spring as possible. So what does Alberta have to offer in the way of native bulbs?

To answer that question, of course, one has to first define ‘bulb’ (‘Alberta’ being well defined and ‘native’ seems okay when not scrutinized). Bulb does have a reasonably precise technical definition relating to food-filled underground shoots and leaves, but after the botany final exam is over, no one seems to adhere to the limited concept, but instead embraces any underground storage organ that looks bulbish to them. To avoid more confusion than is necessary, my definition of a bulb is anything listed in the bulb bible: “Bulbs” Revised Edition 2002 by John E. Bryan (Timber Press, Portland OR). So tubers, corms, rhizomes, and some fat roots qualify.

Much to my surprise, I find that I have planted 4 Albertan true bulbs (Allium cernuum, Allium schoenoprasum [chives], Lilium philadelphicum, Camassia quamash), one AB ‘bulb’ (Maianthemum canadense), and three ‘bulbs’ from nearby areas that might reasonably have been expected to eventually make it to Alberta on their own (Iris setosa, Iris versicolor, Liatris spicata). That’s the good news. The bad news is that none of these plants is so foolish as to produce flowers in the earliest spring! In fact the Liatris (aka Blazing Star or Gayfeather) is sitting frozen in mid-bloom at the moment. No, spring colour is up to the 60-odd accessions (i.e. named species, varieties, or cultivars) of exotic alien bulbs – the vast majority of which do their best to add some early spring colour to the HBG.

Yes, it is true, the Home Bug Gardener has planted almost 10 times as many species/varieties of alien bulbs as of North American natives. I’m a bad, bad, bad native gardener, or at least not much of a purist. And that’s okay with me, because after 8 months of winter, I need to see something attractive in the garden, even if it is an evil alien. Not that these plants are especially bug-friendly. It is true that the bees and flies that are around will visit many of them, but not with the same fervour that they go after later bloomers. The earliest HBG bloomer, the native coltsfoot (Petasites palmatus), really is a bee magnet. But then again, so are many of the exotics that put in an appearance later in the Spring. The bees and bugs may be particular about what they feed on, but I don’t think they have any bias about country of origin.