Rodger Whitlock totototo@pacificcoast.net
Thu, 30 Dec 2004 11:23:52 PST
On 28 Dec 04 at 9:31, John Bryan wrote:

> ...Bulbs in cold storage in boxes and covered with wood shavings,
> were killed when they became frozen due to being too near the
> cooling unit, being placed in the location by mistake, i.e. too
> close to the cooling unit. This is a fact for which I can vouch.
> All types were killed, orientals, trumpets, species and Asiatic. In
> the ground such does not happen, possibly because the soil, around
> the bulb, if it becomes frozen, acts then as an insulator...

The earth itself is a source of heat, and a bulb at some depth in the
soil is simply at a higher temperature than one at a shallower depth.

It's for this reason that sunken coldframes and even greenhouses have 
some heat budget advantages over those perched on the ground.

Likewise, even above ground, unheated coldframes and greenhouses
offer some protection from cold weather simply because they slow
down heat loss from the pots inside to the environment.

Also, pots on a raised bench are much more prone to freezing damage 
than the same pots placed on the ground: simple thermal contact 
makes the difference in this case.
Rodger Whitlock
Victoria, British Columbia, Canada
Maritime Zone 8, a cool Mediterranean climate

on beautiful Vancouver Island

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