"Ed Adamthwaite" wrote in message
...
Hi Kylie,

- what is your hothouse made from? if it's not too much trouble to
describe it briefly.

Its made from steel hoops with plastic film stretched over it. I bought it
from Monbulk Rural Enterprises.
http://www.monbulkrural.com.au/
They make them to size in approximately 2.1 meter increments in length.
The
film is made with a non-drip inside surface and has a slightly insulative
property. I added 3 extra rails, a central rail between the top of the
doors
and one down either side at about 2 metres high offset 100mm inwards.
These are used for supporting the twine that the tomato clips attach to
and
for supporting a trellis mesh when needed. The irrigation feed lines for
drip irrigation run down each side and along the central rail.

As a general rule the daytime temperature inside will reach nearly
double the outside maximum, so it is important to keep the doors open on a
day that goes over 23 degrees max. Tomatoes require somewhere between 12
and
14 degrees for the chemical process that makes them turn red, so the
greater
temperature of the hothouse means that the tomato season is increased in
length.

and i take it you are growing directly in the soil, yes?

Yes. The Dandenongs mountain soil is acidic and clay based, parts closer
to
the clay under-soil where I placed my hothouse had a pH of 5, so quite a
bit
of preparation was called for to get it back to the optimum of 6.5. I have
made a double bay compost bin and will be digging in a bit over 1 cubic
meter of compost after this growing season to increase the biota in the
soil.

interesting, thanks! those greenhouses look nice! i have one (plastic as
well) but it's pretty basic, and the plastic is even worse since the Great
Greenhouse Mishap of 2006. I aspire to a really nice one one day. ;-)

i succumbed & started using derris dust, if that helps you for next year.
i could keep the butterflies off iwth netting, but not the moths (which
are smaller).

I tried some derris dust, but didn't like the idea of eating the broccoli
heads as it is quite hard to wash them out, so gave up.

it is? i haven't had any trouble at all, but then my broccoli heads are
quite loose for some reason. (might make a difference, i don't know!).

one year i am going to try enclosed boxes made of flyscreen
& see how that goes

The flyscreen sounds good, but I wonder if it might shade too much of the
light. If you do try the flyscreen boxes, please post the results.
I'd like to hear how they go.

someone here wrote in once that they used shadecloth boxes & it worked well.
this summer i have had a shadecloth top over the broccoli & cabbage &
they've been fine (and haven't bolted either! as i was genuinely expecting
they might as they went in late). so i feel pretty sure flyscreen would be
all right. at any rate, if i ever get on with it, i'll report!
kylie