"Wally" wrote
They do not like any check on growth. So they need water if it's dry etc
although I haven't found that a problem this year. To keep the curds
white you need to bend/snap a few of the leaves over the curd so they
stay in the dark. The variety does matter too, we prefer the spring ones
as these grow with no insect damage and no possibility of any meat
amongst the curd. (Winter Walcheren Amardo April is one such)

Did you use any fertilizer and what is the pH of the soil?

Hi Bob, No I haven't use any fertilizer and the pH is something else I've
got to learn about.
This is my first year on an allotment and been thrown in the deep end
with very little knowledge of gardening.
Overall I am very pleased with my results but have failed with a couple
of things, namely , cauliflower, onions and carrots, although when my
carrots failed e.g. very small and forked, I put in another lot (although
I
was told it was too late) they came up fine and I am still bringing them
home.

First thing, if you keep taking food out of the soil you have to put food
back. Otherwise eventually your harvest will decline drastically year on
year. I've seen it happen with "new" allotment gardeners. Even some
"Growmore" thrown on the cabbage patch will help as it also contains lime.

We get two loads of well rotted horse manure delivered every year and that
goes onto our potato patch, about 4 inches thick, for the coming year. The
next year that patch becomes the cabbage patch and receives two 25Kg bags of
lime (to ensure the correct pH). We use a 4 year rotation so after 4 years
every patch will have received manure and lime. Hope that makes sense.
We also use seaweed extract as a liquid feed and chicken muck pellets and
Growmore and Tomato feed too.

Whilst the pH isn't that important for most things, unless it's way outside
normal, it is worth getting it checked or getting a meter as some things,
and brassicas are one, prefer certain values. All brassicas prefer a
slightly alkaline soil (above pH 7) which is why a lot of gardeners lime
their cabbage patch. The more manure you use the more important it becomes
to check your pH.

You aren't the only one who had problems with onions this year, I've heard
others say cauliflowers are difficult so you aren't alone on that one
either, however I always suspect that the pH may be the problem. The usual
problem with carrots is germination, it's why we keep our own seed, so if
you got good germination and eventually a good crop ensure you use that same
variety again, it suits your soil/situation.


--
Regards
Bob Hobden
17mls W. of London.UK