permaculture

[Richard Archer <permaculture@juggernaut.com.au>]

Greetings,

I'm developing a site that tends to be frosty through winter and
into mid-spring. Overnight low temps get down to -6 C. Daytime
maximums in Winter range from about 4 C to 14 C.

This isn't an icy climate, but frost-sensitive plants don't do
well. For example, I have a lime tree that's planted in a fairly
protected spot, but after 6 years it's still just a stick which
has all it's new growth frosted off every year. Poor thing.

I'm planting mostly frost tolerant trees and plants, but would
also like to plant some frost-tender species such as limes,
passionfruit etc.

I've read all the books, and there seems to be some things that
can be done to create frost-free microclimates. But I've tried
some of them and they failed miserably.

I'm wondering if anyone can share their experiences (good or bad)
about some of these techniques:

- Diverting frost around an area by creating a V-shaped planting
with the point of the V uphill.

- Sun traps - a parabolic planting facing sunwards and to hopefully
retain sufficient heat from the day to prevent frost at night.
Can also use water to reflect more heat into an area.

- Growing trees espaliered against a sun-facing rock wall.

- Growing trees and vines around water tanks.

- Creating sufficient thermal mass with surrounding large trees
and structures to prevent frost from settling.


And in a non-permaculture approach... has anyone had experience
with overhead sprinklers automatically triggered with a frost
sensor?

FWIW, I tried a suntrap on a small scale, and it seemed to have
no effect at all. Hence the lime tree stick.

 ...Richard.