The message
from Theo Markettos contains these words:

Last year we moved in in July and it was heavily cropping: I don't think the
people who were here before us for 2 years touched it. So we were eating as
much rhubarb as we could and it was still going in October. I covered it
with maybe 1-2cm manure and come March it was peeping up again. As far as I
could see the woody bit of each plant was maybe 1ft across.

You shouldn't pull any after mid-June.

It's been growing vigourously since then except about three weeks ago there
was a storm in which what appeared to be icecubes fell from the sky - they
were solid clear ice, not white like hailstones, maybe 7mm across. Having
this pelted at it flattened the rhubarb quite considerably and it's looking
rather unhappy now, like it's been sat on. We haven't been eating very much
since then. There are lots of thin (1/2 inch) shoots at ground level, but
fewer thick shoots going upwards.

That's because you overcropped it last year. It might never recover.
Unfortunately, the remedy (digging up a crown in the autumn,
splitting-off the outside new growth, and preparing a bed and planting
only the outside bits) leaves you without rhubarb for a year - unless
you can dig one crown and make a new bed.

Of course, a year is a long time in student accommodation.

I pulled some of the broken stems yesterday (there were some with ants
living inside) and took about 8 more good ones to eat. So I'm wondering
what's the best thing to do: pull more so new growth comes through or thin
out to allow existing squashed ones to fatten up? Does it matter, from the
plant's point of view, that the shoots are flat against the ground with thin
stems since I assume they are still receiving sunlight OK?

Leave the damaged stuff. Pull new growth when the leaves have
uncrinkled, but before they go dull and leathery. If you have a
pressure-cooker, put freshly-cooked rhubarb in screwtop jars in the
pressure-cooker, and simmer for a while.

Replace lids on jars and leave them for half a minute (for the space to
fill with steam and expel the air), tighten lids.

Keep in a dark place, and the rhubarb will keep indefinitely.

But don't pull any after mid June!

--
Rusty
Open the creaking gate to make a horrid.squeak, then lower the foobar.
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