Wed, 30 Jan 2008 15:29:46 PST
On 30 Jan 08, at 7:01, Judy Glattstein wrote:

> Coldframes have been mentioned on several occasions. Later in the
> Spring I'll be teaching a one day class about cold frames, and would
> be interested in members experiences - when you started, how it's
> built, what you grow. I want students to know that there are numerous
> people out there who use these handy adjuncts to gardening in a
> diversity of ways for growing many different plants. Since this is
> possibly somewhat off-topic, anyone who wants to share information is
> welcome to e-mail me directly.

I prefer to respond openly so if someone thinks I'm nuts, they can 
say so.

Some observations drawn from my own experience:

1. Glass is better than any plastic for the cover because it is more 
transparent to start with, does not darken or go opaque, and doesn't 
go brittle with age.

2. Don't make the frames too deep, otherwise your bulbs are at the 
bottom of a box and will reach for the light. The ideal is a 
coldframe that has transparent walls as well as the cover.

3. Make sure the cover can be opened slightly for ventilation.

4. Only shut cover down completely during really cold weather.

5. The ideal is a frame over a sand bed so pots can be plunged.

6. Make all your frames the same size so covers are interchangeable. 
(This may conflict if point 1 drives you to use old windows for 

7. A common construction technique has planks stacked on edge to make 
the surround. The planks must be tied together vertically. Put the 
vertical elements *outside*, not *inside*.

8. Square pots pack more tightly than round pots.

9. Make sure the cover has a slope to throw off rain.

10. Make sure the cover is strong enough so it won't collapse under a 
heavy snow load.

11. Make screen covers for use during spring, summer, and fall to 
keep flying pests out. This advice particularly applies if you are 
growing amaryllidaceous bulbs and your area is infested with 
narcissus flies.

12. Pay attention to sun and shade when you site. Middle eastern 
bulbs want lots of summer sun, but woodlanders want summer shade.

13. If you use wood, be sure to paint with a good wood preservative. 
You will need to repeat the application every few years.

14. Wood coldframes have the advantage over masonry ones that you can 
pick them up and move them if you want to.

15. Here in the Pacific Northwest, the primary purpose of coldframes 
is to keep the rain off during the winter.

Rodger Whitlock
Victoria, British Columbia, Canada
Maritime Zone 8, a cool Mediterranean climate

on beautiful Vancouver Island

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