cold weather miscellany
totototo@telus.net (Wed, 09 Dec 2009 11:11:14 PST)
My own experience with the mass death of potted bulbs, during the Big Freeze of
February 1989, suggested that the wetter they are, the less hardy they are.
I speculate that Jane's death toll may be increased if she didn't cover her
pots during the spells of heavy rain we have had in the last few weeks.
It's too late now, of course, but if you have "hardy" bulbs in pots, you can
reduce damage from the next transient freeze in several ways:
1. Park the pots on a paved or very well drained (i.e. gravel) surface. If you
put them on soil, they will get a lot wetter.
2. Protect your potted bulbs from the rain. Put them in a covered cold frame,
under the eaves of the house, or even just throw a tarp over them - anything to
keep the rain off. Even old window sash placed on top and weighted down with a
few bricks will do, but remember to slope them so the water runs off.
3. During cold weather, even the most minimal protection is better than none. A
few old bed sheets thrown over your pots, with a windproof tarp or sheet of
plastic over that, will do a surprising amount of good.
4. Coldframes should be shut as tightly as possible, and again a tarp over them
will help. It will also help to spread single sheets of newspapers over the
plants inside; the earth acts as a source of heat at about 50F, so any form of
overhead insulation will raise the temperature and reduce damage.
5. Plants known to be on the tender side should go into frost-free storage by
the end of November in the Pac NW. An unheated room in the house, the garage,
the basement (if unheated) etc will do. The plants will do better if taken back
outside once the weather relents, as such storage areas tend not to be well lit.
6. It pays to watch the weather very closely. These arctic outflows are due to
high pressure systems to the east of the Cascade, so if you see a big high
pressure system over Alaska, Yukon, NWT, or Alberta, take heed. Keep on eye on
the jet stream path, too, as it can drag icey air much further south than usual.
My advice is strongly influenced by the weather patterns in the PacNW west of
the Cascades. Those living in other regions wil have to view them as a starting
point for devising approaches more suitable to their climates.
--
Rodger Whitlock
Victoria, British Columbia, Canada
Maritime Zone 8, a cool Mediterranean climate
on beautiful Vancouver Island