On Jun 13, 9:04*am, Jeff Layman wrote:
On 12/06/2011 17:42, Dave Hill wrote:

Thanks to the EU banning more chemicals I can no longer use a pre
emergent herbicide on the dahlias so I have had to switch to a ground
cover / mulch fabric,
This comes in a 100m roll 1.4 m wide and has to be layed by hand.
http://i240.photobucket.com/albums/f...undcover02.jpg
I've now put down 16 beds and will put short beds accross the top at
right angles to the main batch.http://i240.photobucket.com/albums/f...undcover03.jpg
All I have planted so far are my "Tree dahlias" 78 of them.
The main batch of dahlias will be planted through the mulch which will
have to be lifted to lift the tubers in the Autumn, I will also be
doing a 1000 or so pot tubers (I Hope) and another 800 seedling
dahlias also in post which will be planted through the sheeting but
which should lift leaving the sheet in place for next year.
David Hill

I don't know if it would be possible, but could you plant your dahlias
in (large) water-lily containers - those things which are open-weave
plastic baskets? If they were planted at ground level, could you not
attach binder string (or something similar) and just lift them through
an X cut in the membrane before winter? *It's too late now, but if it
worked you could save time by just using a square metre of fabric above
each basket, rather than lay out whole rolls and plant through them.

Of course, all this would depend on the dahlias not being able to form
tubers outside the basket.

Whatever, it seems you're in for a lot of work thanks to the EC zealots.

--

Jeff

Thanks both for the ideas.
Basamid or Dazomet to sterilise the soil, is one thing I had thouht
about, BUT
We have a high rainfall and I am dealing with a site of around half an
acre.
You need to rotovate the ground well, then apply the chemical and
rotovate it in, cover the ground with polythene for 7 to 10 days, then
remove the cover and rotovate again to get the fumes etc out of the
soil.
With our rainfall, and on sloping ground this could give rise to a few
problems, including runoff or heavy rain from that area, holding the
sheet down etc.

Pot growing the dahlias in large containers would be a problem as we
have a heavyish loam and plants wont pull out without digging, also
the cost of up to 5000 pots would be much more than the cost of the
sheeting.
The problem with using squares of fabric would be weed growth between
each square, and the wind blowing the sides up unless you hold each
side down with soil or pins or something.
It would be possible to grow all the dahlias in large pots, say 12 to
15 inch and stake them, letting the roots grow through into the
ground, but the cost of pots and compost would be excessive. OK if you
were growing a dozen or so, but not in my numbers.
David