It's good that you are asking these questions. (I see that you have some
good answers so far.)
It's human nature to try to "fit in" all the seedlings that you start.
One of the big mistakes beginners make is planting the garden so that it
looks about right when the plants are small but not thinking about how
much room each plant will need when it gets big.
I've had people show me their garden and ask why nothing is doing well.
Often they will have 4 or 5 zucchini plants where there is room for one.
They didn't have the heart to thin the carrots and wonder why they all
end up so small. Maybe enough corn in 10 square feet that could use 50
square feet of space for that many plants. They wonder why most of the
plants produce nothing or only a small ear of corn.
Well, that's a little extreme but do get used to thinning properly and
planting out with a decent spacing between plants. Throw away what there
isn't room for. The garden will turn out MUCH better in the end.

Steve


rich79 wrote:

This is my first season of growing vegetables and it appears i am a
better farmer than i thought i would be! I only have a small patch and
an average sized greenhouse and i think i may have planted to much. I
now have hundreds of seedlings growing of all sorts of varieties and
species. I imagine in a few weeks when they get bigger i will have to
thin them out and discard some of the seedlings which i don't really
want to do but i don't think i'll have any alternative apart from
giving some to neighbours. What i wish to know if anyone could help me
is minimum spacing for individual plants for Brocolli, Cabbage,
Spinach, Onion, Carrot, Courgette, Sweetcorn, Parsnip and Tomatoes
(money-makers)!!! Also, when i should start thinning out, at the moment
they are all to small and delicate to move. How many weeks after they
seedlings first appear are they strong enough to survive being moved
about?