[permaculture] Creating frost-free microclimates
George Anna Clark
esac at laneta.apc.org
Mon Oct 22 20:53:54 EDT 2007
Almost forgot to report...
I met some campesinos in the state of Tlaxcala, Mexico who swear by
water-filled glass bottles, placed in the paths between the vegetable
beds. I assume their temperatures dip only a few degrees below 0....
good luck,
george anna
south-central Mexico
jedd wrote:
>On Fri, 5 Oct 2007, Richard Archer wrote:
>
>
>>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.
>>
>>
>
> I get down to -4, maybe -5 - but in winter at least get higher
> temps - usually up around 20C. (Where are you, btw? I'm around
> the top end of the hunter.nsw.au)
>
> Warmer day time temperatures make it easier to use a pebble/stone
> mulch for its thermal inertia. Another frost-protection method you
> didn't mention is covering the young plant (once it gets to a certain
> height its new growth is typically better protected) with a tripod of
> timber and growing winter vines over the thing.
>
> Or even using an artificial covering -- I usually bubble wrap my
> passionfruit, for example, from May through September. This is
> easy to do as its growing on a trellis, so the framework to attach to
> is easy. For standalone plants you need something special - 4x steel
> posts with 2" polypipe loops over the plant and shadecloth over the
> top, for example. The same structure is reusable in subsequent
> years, or alternate for summer protection of other plants.
>
>
>
>>- 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.
>>
>>
>
> You definitely need something to accumulate and release the heat
> with this approach, and rocks are typically the best option. You
> may need a backup plan in the event of several days of 4C max, as
> you just won't get the necessary heat input to keep you going
> through the nights.
>
>
>
>>And in a non-permaculture approach... has anyone had experience
>>with overhead sprinklers automatically triggered with a frost
>>sensor?
>>
>>
>
> I haven't tried this, as I don't have sufficient water pressure (I'm
> on gravity feed only) to do sprinklers, and I'd be worried that all
> my plants would die in one night if the power or sensor went out.
>
> I can recommend getting a couple of temperature dataloggers that
> you can put about the property. These will log temperatures at
> various intervals (mine are usually set to 5 or 30 minute) and run for
> months at a time, then get plugged into a USB port on your poota,
> with the data coming in as a CSV. They're accurate up to 0.5C,
> but are particularly useful for working out temperature differences
> between two or more sites. These are definitely planning devices,
> rather than reactive / triggering devices. The only ones I know of
> are from Jaycar and cost about $120 each.
>
> In the Designers' Manual, Bill talks of frost amelioration by digging
> holes. I never quite got how this worked, and have been meaning
> to try it out - or better yet find someone who's done it and can
> comment on its efficiency. Page 120 / Figure 5.13 for those with
> the tome at hand.
>
> Jedd.
>_______________________________________________
>permaculture mailing list
>permaculture at lists.ibiblio.org
>Subscribe or unsubscribe here:
>http://lists.ibiblio.org/mailman/listinfo/permaculture
>
>
>
>
>
>
>
>
More information about the permaculture
mailing list