"John Vanini" wrote
I thought it was a good idea because the chap's cabbages and broccoli were
solid in the ground, with no supports apart from the tube, and the
stem/stalk of each plant was perfectly straight and quite thick and,
obviously, gave a good support to the head.

Cabbages, Cauliflowers and Broccolli don't need any support normally
although it's true they can lean over a touch which is only a problem for
those who like their rows perfectly straight. We have never even staked our
winter Cauliflowers/Broccolli/Cabbages. Sprouts are another situation
alltogether, they often do need staking and certainly would on a windy site.


I'm relatively new to gardening and am always looking for the correct
and/or the best method with all crops - it's one of the things I find
fascinating about gardening - I always want to learn more.

There are usually as many "correct" methods of growing anything as there are
days in the year. :-)
Provided you comply with any specific plant requirements, anything else is
what works for you.

Regarding Cabbage Root Fly, I wasn't thinking of this pest flying over the
tube to lay its larvae inside but rather of the larvae being laid outside
the tube, in the soil, but then burrowing underground, quite happily, as
normal, until each one bangs its head on the plastic wall! But, then, I
suppose, the larvae will burrow deeper than the 4" of tube buried in the
ground - or do they? I must read up on the Cabbage Root Fly. Normally, I
buy or make the small cabbage root fly mats but I wondered if this method
would make these mats unnecessary.

I thought they landed on the plant and walked down the stem to the ground
where they laid their eggs.

As Mary suggested, it just might stop slugs but then they may be able to
climb a 4" plastic wall - I really don't know.

Only a copper ring around each plant would stop slugs/snails and then when
the plants grew and the leaves touched the ground outside the ring the
little blighters would invade. Must admit we don't get that much problem
with slugs on the brassicas, whitefly is another problem though.

Also, I've seen slugs in potatoes, which were underground, so does that
mean that the larvae would have no problem going under the 4" tube buried
in the ground to get at the roots? Of course, the chap on the allotment
says that hasn't had this problems in the three years he's been using this
method - but he may just have been lucky.

The slugs that attack spuds are ground dwelling, like worms.

Normally, Bob, I do what you do (or very similar) and the main trouble is
wind (not me, personally, but the plants! (lol). The allotments have an
almost permanent south-westeerly breeze which is often far more than just
a breeze. As a result, I stake the most vulnerable plants and buld up soil
around the stem/stalk to give additional support.

In that case try your friends method if it works on your site, all brassicas
like to be firm in the ground so anything that makes them move about is bad
for them.


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