Tuesday, July 10, 2012
Species name: Hosta sieboldiana
Common name: hosta, Giboshi
Hostas are native to China (there are over 40 species in the genus; one species was chosen as the best "base" for hybridization and that species is native to China. The rest are native to China and other areas of Asia such as Japan, Korea, Thailand, Cambodia, etc.) and do have the tendency in some areas to become invasive if left unchecked. The cultivated and hybridized cultivars are incredibly poor at reproducing through seed, but are still excellent at spreading through localized areas through their underground rhizomes. The roots are also incredibly resilient to cutting and other forms of wounding and regrow quite readily. My supervisor talks of cutting hostas out of his garden with a spade and listening to it crunching through roots; he put the mangled stubs into pots and they grew so well they burst through the sides of the plastic pots before he could sell them. Many garden centres will direct you to "gently" dig the hosta out of the ground to separate the bunch once every few years but don't bother being so gentle! Your hosta will be fine.
The unfortunate part about hostas is that they're just so gosh darn popular in North America. And, to be honest, they're not even all that exciting! Sure, there are over 5,000 cultivars of hosta available to be sold but do you really think that someone will love your garden more if you paid $150 for a leaf of an extremely rare cultivar? I would be more impressed if you had trilliums or Jack in the pulpit growing. For some reason there seems to be this mania in North American gardens for hostas and their suffocating foliage (I swear, I'm trying really hard to be unbiased here...). They can't really be grown for anything else since their flowers are essentially scentless (except in some really unusual cultivars, but their flowers smell terrible and not sweet), they don't last long, there aren't very exciting seed pods that appear after the flowers are done, they don't attract any exciting pollinators that every other flower in a garden doesn't attract, and they don't provide any spectacular fall colour aside from green and brown. The only redeeming factor about hostas is that the entire plant is edible, although the youngest parts apparently often taste the best (since the older they get the woodier the tissue and the tougher it is to chew). I haven't tried any of my backyard hostas in a salad or steamed instead of spinach, but now I'm really tempted to try!
Hostas do suffer from a pretty devastating viral disease called "Hosta Virus X". This disease causes a form of tissue wilt and tissue decay, and is very easily spread from plant to plant through the simple action of sap contact (and since sap can exude from the tips of leaves and not even through wounds in the plant's tissue, this poses a real problem). Walking down a pathway of overgrown hostas and brushing up against one plant then another is enough to transmit the disease. On top of the ease of transmission, this virus can often remain dormant in the plant for years (up to 7 years has been reported) which means all of the plants in your garden may be infected before even the first starts showing symptoms. Once the hosta has the virus it's impossible to get rid of even just by pruning leaves because it also lives in the roots and rhizomes. At the first appearance of symptoms in any one plant in a garden (unfortunate to say for my parents since they like them but happily for me since I don't, I'm pretty sure that one of our hostas is currently dying of Hosta Virus X), all of the hostas in that garden should be destroyed by digging the plant and all of its roots out of the garden, replacing all of the soil with new soil, and burning all of the plant residues. Seems like a drastic move, but whenever you put a hosta out by the side of the road as garbage it always seems like free pickings for a gardener down the street; yet another reason why this virus is becoming such a huge problem in the plant population.