cold weather miscellany
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…

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