On 10/05/2015 10:12, Derek wrote:
On Sat, 09 May 2015 21:22:46 +0100, stuart noble
wrote:


That is interesting. I suppose we are conditioned to think plants need
fresh air. I imagine the glass steams up so you can't see what's
happening inside?

Have grown fuchsia cuttings this way since seeing a grower on TV using
coffee jars in the 1970's . The advantages are that the cutting, is
protected from drafts, once it has taken up the water its needs, the
water is recycled out of the leafs down the glass and back up into
the roots.
The glass does not steam up, as too much water would make the cuttings
rot off, the secret is to water well, seal up the jar, and then the
important bit, go back two days later, remove all excess water, wipe
out, any sitting water, then reseal and it will not need any further
care, till the cutting is big enough to move on, and in the winter
that can be months .


Thanks for the detailed explanation. I've been growing sweet peas in
transparent sandwich bags, hung on hooks, which I suppose amounts to the
same thing, except that I've always punctured the sides for ventilation.
This time I've pinched out regularly so the current crop are very
sturdy. However, I always lose a few to mildew, so I will follow your
advice next winter.
Anyone without a vast collection of jars wishing to try the Wardian Case
principle (thanks Chris) might consider my cheating method. I use
Sainsburys large tie handle food bags.