"Sow under glass" and "sow outside".

[organic]

Hey folks, just a quick question about sewing times.
Am I right in thinking that for most things, if I sew under glass in March and then plant out I'll get a crop up to a month earlier than the same thing sewn outside in April?
Or is the gap between the harvests of cloche- or greenhouse-sewn things and outdoor-sewn things not as long as the gap between the sewing times?

Knowing this will help me prune down my rather extensive seed shopping-list so I can get it ordered in the next day or so.

Cheers.

[binley100]

Not necessarily some things still catch up from a later sowing.

[Suky]

I had this quick vision of you stitching seed beds in the greenhouse rather than sowing seeds This is not a comment on spelling - rather the way my mind works when I glance at what is written without reading properly.

To answer your question, I agree with Binley, most things catch up except things that need a longer growing season.

[sarraceniac]

I find that things sown under glass a month before the same thing sown outside, mature about two weeks earlier. This is not only temperature but light conditions as well. As Suky says, things like chilli which is slow maturing do need that extra few weeks but most things, even tomatoes, catch up.

[organic]

Suky - that really made me laugh. I usually have to check whether I've written sew and sow as I do often put the wrong one - apparently that slipped through the net. I'm glad you got a funny vision out of it though.
Even when spelled correctly I do find it amusing to see things that read like "sewing" in odd ways. My girlfriend has a sewing machine she uses a lot so I'm already inclined to make the connection.

Thanks for the replies... So for the following things currently up for the (temporary) axe from my shopping list, would you expect them to catch up or should the ones started under-glass be ready for harvest earlier?

Carrots (Sugarsnax)
Calabrese (Waltham or Pacifica - I'll only get one but undecided which yet)
French Beans (Triomphe de Farcy)
Brussel Sprouts (Rubine and Groninger)

Then again, for 2 weeks I might just axe them until the next payday anyway!

Decisions decisions!

[Two_Sheds]

Sugarsnax was discussed on an earlier thread, and the consensus was not to bother: it's no tastier than any other carrot

French Beans obviously can't go outside until after your last frost, and any cold will check their growth, but if you get the timing right you'll have an earlier crop. They can be succession sown too, so you get crops right up into autumn

[organic]

Thanks for mentioning that thread, TS. I've just done a quick search and read the one I think you mean. (And you didn't even need "to mention the rather excellent Search function again"! )

On balance I think I'll forget putting the above under glass and just sew them direct (or in a seed bed) closer to the time.
Cheers.

[Two_Sheds]

I'll forget putting the above under glass and just sew them direct

you gone done it again

[organic]

Err...
I actually meant needle and thread that time though...
Yea, that's right, I'm going to sew instead of grow for those things.

[snohare]

This spelling lark...it is a real sow and sow, isn't it...or is that "a reel sew and sew"...well, so it would seem (seam?) !
Not having a greenhouse, I tend to sow indoors, grow on windowsills, and then plant out in cold frames. This doesn't get me an early crop, at this latitude it only helps me in an attempt to catch up with you lot ! (In Aberdeen we are usually a month to six weeks behind.)
Be warned that some plants just don't like to be grown under glass, or not unless it is horticultural glass at least. This is probably because normal glass filters out some wavelengths of UV, and there are three different metabolic pathways by which plants can derive energy from photosynthesis; some are less effective than others, so the plants will languish under glass, while with some plants, the extra warmth makes up for this as it is nearer the optimum temperature for the particular proteins used by that species or cultivar. Lettuce absolutely loves being grown under glass, and does well on a windowsill (as does the yellow carrot I am saving for seed, from my organic veg box last autumn).
My theory is that those plants such as brassicas that are evolved for cold-weather will (generally) also do well with low levels of UV as they are not only better optimised for low temperatures but also for the lower levels of UV found at higher latitudes and in winter conditions.
The old gardener's adage we all ignore of course because we lack superhuman restraint is, "Sow according to conditions, not calendar" !
I don't know how anyone else does it, but I have found the best way to grow non-root seedlings is to stick them into compost in a plastic carton with holes pierced in the bottom, then put that in an identical plastic box with a little water in it; renew with fresh rainwater when needed, and use camomile tea to avoid damping off.
And so tapers off this thread...I'm a-frayed !

[sarraceniac]

I always thought that horticultural glass was just 'domestic' glass with imperfections. Doesn't matter if there are a few ripples in it because nobody uses it for their living room window's view. That is why it is slightly cheaper. That's what I was told anyway.

[snohare]

I was told it had different properties to normal glass, it was more like plate glass which doesn't filter UV - but maybe you are right !

[organic]

Thanks very much for that reply, Snohare. Very helpful for sure.

It'd make things a bit easier if seed packets referred to conditions rather than the calender... if a little less clear cut.

[snohare]

I was delighted to find a sticky by Two Sheds on the Growing Techniques Forum on germination temperatures - I have saved web pages somewhere with the info, but this will save me having to dig for them !