Monday, May 23, 2011
Death of a Mystery Plant
Saturday 9 June 2007, like many a June weekend in the Home Bug Garden, was a day of planting, transplanting, weeding, and enjoying what sun, flowers, and bugs were in evidence before the usual afternoon clouds, thunder, and rain. Along the well shaded west side of the garage, I found something new and interesting – a tiny seedling with leaves with small, hairlike teeth on their margins. I was very excited because the leaves looked a lot like those of an Epimedium (variously known as Bishop’s Hat, Barrenwort, Fairy Wings, and Horny Goat Weed). In spite of the mostly off-putting common names, barrenworts are graceful plants with attractive foliage and pretty flowers. Moreover, barrenworts are reputed to do well in dry shade – the most difficult spot to fill with plants in any garden. The urge to splurge on epimedia at the local greenhouse was strong, but tempered by the high price, the usual Zone 5 rating (HBG is a Zone 3 garden), and a failed experiment with a West Coast native Redwood Insideout Flower (aka Redwood Ivy) Vancouveria planipetala. Like barrenworts, the insideout flowers belong to the barberry family, Berberidaceae, of which the Home Bug Garden was otherwise bereft.
Well, what luck, both a new family (those bitten by the collector’s urge will understand this) and a possible dry shade tolerant groundcover! So, I immediately transplanted the frail seedling to the dry shade under the Colorado Blue Spruce in the front and have been babying it along ever since. Attempts to identify the mystery seedling were unsuccessful – even the University botanist would not venture a guess – and it looked like we would have to wait until it bloomed to discover its secret name.
The seedling survived the winter of 2008 and by 2009 had formed a woody base and stem. This seemed to rule out barrenwort, because these have wiry stems. So, later in 2009, encouraged by the luck my fellow Edmonton gardener NorthernShade Gardening has had with her epimedia, I dropped a dollop of my disposable income at the local greenhouse and came home with a Epimedium grandiflorum 'Lilafee' and a Epimedium x warleyense 'Ellen Willmott'. Both were rated for Zone 4 by the optimistic greenhouse, but rather than risk them in the dry shade, I put them in my most protected and moist shade bed. Both barrenworts survived the Winter of 2010 and, although the leaves died off this winter, new sprouts are just coming up now. Meanwhile, the mystery plant kept slowing growing and was about half a metre high today with lots of ciliated leaves each with 2-3 sharp thorns at their base.
Then Gardening Zone 3b posted on harbouring criminals. I was too busy enjoying the warm, partly cloudy weekend – perfect for planting out – to read blogs. But, good weather never lasts long in Edmonton, and Victoria Day dawned cool (+7 C), wet, and by noon had dropped to +4 (40 F) in the rain. Rather than dwelling on the chance of the temperature dropping a few degrees more and that damned white stuff returning to bury frozen tomato seedlings, I’ve caught up on my blog roll and have discovered that I have been nurturing a Prohibited Noxious Weed – Common Barberry (Berberis vulgaris). Although the leaves are poisonous, the berries are used to make jam in its native Afro-Eurasian range. Unfortunately for barberry aficionados, birds also like the berries and spread the shrub and barberry is an intermediate host of stem rust of wheat (Puccinia graminis). Alas, into the rain and watch out for the thorns.Bighead Knapweed (Centaurea macrocephala). Also called Giant Knapweed, Armenian Basketflower, and Lemon Fluff Knapweed,
A total of 9 species of Centaurea Knapweeds (and Russian Knapweed Rhaponticum repens) are posted as Prohibited Noxious Weeds in Alberta (see the Zone 3b post) and 5 more are listed as Noxious Weeds by the USDA. None of these is Balkan Knapweed (Centaurea atropurpurea), a somewhat creepy plant in bud, but attractive to both people and bees in bloom.
My first Balkan Knapweed came back from a visit to the Devonian Botanical Garden in 2005. It didn’t bloom until the third year, but now there are a dozen or so seedlings around the yard. I think I will err on the side of caution and grub them out too. I suppose this is a bit bigoted of me, but I'd rather not be the source of a new weed, no matter how attractive and bee-friendly.
The difference between Prohibited and every day noxious weeds is that the populations of the former are still small and restricted and there is a chance of preventing them from spreading. To quote the AB Invasive Plant Identification Guide: "Plants in this category are either not currently found in Alberta or are found in few locations such that eradication could be possible. Under the Weed Control Act a person has a responsibility to destroy a prohibited noxious weed." Those Noxious Weeds not prohibited are probably here for good. As with the common dandelion (Taraxacum officinale F.H. Wigg. ssp. officinale), some day they may fall off the list and be just another interesting or annoying member of the flora.