What a flop!

[whydoineedone?]

In the spring I planted, from seed, so much stuff in my greenhouse - cabbages, carrots, onions, coriander, peppers, chillies, garlic, lettuce, cucumbers, asparagus, courgettes, pumpkin.....the asparagus and carrots are so thin they would thread through the eye of a needle, the cabbages and lettuce are thin and spindly, the onions are just like long grass, and the rest just disappeared completely. What am I doing wrong? I used a decent seed compost, kept the greenhouse warm, watered and fed the stuff....next year I won't bother with seeds, I'll just buy the plants. Should I simply have planted the seeds directly into the vegetable plots, and can I save any of it (eg. the spindly cabbages and lettuces) if I plant them out now?

[veggiechicken]

Hi and welcome!
I have to ask Why do you need one what? That's too cryptic to be ignored!
As for your seedlings, did you prick them out after they'd germinated?
Thin and spindly could mean that they were overcrowded and struggling for light.

[Darthcider]

Guessing, why do I need a user name?

Welcome from sunny South Wales.

If you have nothing, just plant stuff out and hope they catch up.

[DWSmith]

The first thing I think of when I hear spindly is the light intensity is too low and the light duration is not long enough.

LOTS of light when the seeds sprout.

Watch some youtube videos about grow lights. The fluorescent tubes will almost be touching the tops of the plants.

Bright lighting in the proper band of wavelengths.

[Guest]

the asparagus and carrots are so thin they would thread through the eye of a needle

Asparagus is a long term crop it will be thin and spindley for several years whilst it establishes. Each plant should be potted up and over wintered, then planted out in spring in a prepared bed that had good drainage.
Carrots are best sown direct into the veg patch and do not transfer well. You can grow them in pots but you need a large pot for a few carrots and they are likely to be smaller anyway

the cabbages and lettuce are thin and spindly

These can be separated and planted out to bulk up. The cabbage will benefit from some lime and netting. Hopefully they are not too spindly and you will get something.

the onions are just like long grass

Again plant out. You may only get small onions as it is quite late for planting out.

and the rest just disappeared completely (coriander, peppers, chillies, garlic, cucumbers, courgettes, pumpkin.....)

If they have disappeared rather not appeared they have probably been slugged. Garlic may have rotted off. You might be able to pick up some of the plants you lost from the gc on the cheap about now.

Isn't gardening fun. Keep at it, it is great when something finally goes right.

[Snoop Puss]

I agree with everything Norfolkgrey says. Plus, as well as plants needing a fair bit of room, they also need a fair bit of time. Even a lettuce takes quite a while from sowing to harvest. You say you sowed your seeds in spring, but that could be quite recent depending on when exactly.

Don't be disheartened, though. As Norfolkgrey says, it's great when things go right.