In article , ajr
writes

A row of carrots, spinach and beetroot, as well as a row of marigolds (my
father told me that they would 'kill off' carrot fly!).

Most of these rows have small 'seedlings' growing, but I have no idea
whether they are weeds or the plants that I am trying to grow. Can anyone
point me in the direction of a site that has pictures of seedlings, so I can
distinguish one from the other?

This is from memery, so may be wrong!

Carrots have very long fine cotyledons (the first 'seed' leaves) and
then the first true leaves appear very find and hair like between them.
Beetroot naturally comes as clusters of seeds (though they now sell them
in a single form) and has strap like cotyledons a bit wider than the
carrot ones. You start getting hints of the red quite early on.

Also the spinach, marigolds and carrots have failed to show themselves yet -
do they usually take three + weeks to germinate?

can do easily.
For future reference - parsnips and parsley are notoriously slow to
germinate.

Not much help to you now, but I used to plant radish seeds about 1 inch
apart along any row where I was planting veg seeds. The radish
germinated very quickly and showed me where the rest of the row was, and
they were ready for pulling before the other plants were big enough to
have problems with the radish competing for space.

--
Kay Easton

Edward's earthworm page:
http://www.scarboro.demon.co.uk/edward/index.htm