new garden spot - cover w/ plastic to kill weeds over winter?
 

We excavated for a new patio in the spring and have a large berm of
relocated topsoil that's just right for a pumpkin patch next year.

The berm is totally covered in a very common weed here in NC - looks
like bamboo/grass, easy to pull, grows 2ft tall or so. Just mowed it
down, but was wondering if I could kill the weed seeds by covering it
now w/ black plastic until next May.

Have ordered Dills Atlantic Giant pumpkin seeds - anyone have any
experience in nc growing these? Should I ammend soil now in
preparation for next year? thx!

like bamboo/grass, easy to pull, grows 2ft tall or so. Just mowed it
down, but was wondering if I could kill the weed seeds by covering it
now w/ black plastic until next May.

I have heard that covering soil with plastic isn't a good idea. It has
something to do with the air not being able to get into the soil, as well as
problems with the water getting in. Apparently it can make the soil sterile
or at least not the best for growing things well. I think mulches of almost
ant sort are a much better solution.

Jen

"sarab" wrote in
oups.com:

We excavated for a new patio in the spring and have a large berm of
relocated topsoil that's just right for a pumpkin patch next year.

The berm is totally covered in a very common weed here in NC - looks
like bamboo/grass, easy to pull, grows 2ft tall or so. Just mowed it
down, but was wondering if I could kill the weed seeds by covering it
now w/ black plastic until next May.

Have ordered Dills Atlantic Giant pumpkin seeds - anyone have any
experience in nc growing these? Should I ammend soil now in
preparation for next year? thx!


Yes, when done properly it's 'solarizing' the soil. Black plastic laid
down, with a few large rocks or other objects which give a bit of air
underneath here and there is all you need. Over the winter, the heat
generated beneath the black plastic will of course cook all the weed grass,
and as an added bonus also cook the thousands of dormant weed seeds the
excavation brought up. If it was me, I might also lay down as much organic
material as possible (yard clippings, leaf mulch, etc.) before the black
plastic. All that material will compost and make a great topsoil layer.

--
David J. Bockman, Fairfax, VA (USDA Hardiness Zone 7)
email:
http://beyondgardening.com/Albums

On 18 Sep 2005 08:32:04 -0700, "sarab" wrote:

We excavated for a new patio in the spring and have a large berm of
relocated topsoil that's just right for a pumpkin patch next year.

The berm is totally covered in a very common weed here in NC - looks
like bamboo/grass, easy to pull, grows 2ft tall or so. Just mowed it
down, but was wondering if I could kill the weed seeds by covering it
now w/ black plastic until next May.

Have ordered Dills Atlantic Giant pumpkin seeds - anyone have any
experience in nc growing these? Should I ammend soil now in
preparation for next year? thx!

Where I live in Ohio I've done this with plastic several times, but in
the summer. I doubt if it's hot enough here for it to work well in
winter. I've never grown pumpkins, but I grow watermelons every year.
With those there's only a small area that the vine roots in, the rest
is the sprawl of the main plant. I've used plastic for this area, but
now I use newspaper covered with grass clippings and leaves. It's
important to set up drip irrigation on the root area before planting,
as you can't get to it once things are really growing. So maybe you
could do something like that, dig up the grass in your rooting area,
and put down a mulch that will stay through next season where the
vines will sprawl.

"sarab" wrote in message
oups.com...
We excavated for a new patio in the spring and have a large berm of
relocated topsoil that's just right for a pumpkin patch next year.

The berm is totally covered in a very common weed here in NC - looks
like bamboo/grass, easy to pull, grows 2ft tall or so. Just mowed it
down, but was wondering if I could kill the weed seeds by covering it
now w/ black plastic until next May.

Have ordered Dills Atlantic Giant pumpkin seeds - anyone have any
experience in nc growing these? Should I ammend soil now in
preparation for next year? thx!


I had better luck with corrugated cardboard boxes. I happened to have a lot
of them after moving into a new house. Laid them over the soil, covered with
leaves, hosed it down heavily, and it pretty much stayed put all winter. It
was easy to chop up with spade & fork in the spring, except for a few boxes
whose packing tape I overlooked.

I had better luck with corrugated cardboard boxes. I happened to have a
lot of them after moving into a new house. Laid them over the soil,
covered with leaves, hosed it down heavily, and it pretty much stayed put
all winter. It was easy to chop up with spade & fork in the spring, except
for a few boxes whose packing tape I overlooked.




I've heard that thick bunches of newspaper are good too, especially if
covered with heaps of mulch. And it can all be dug in later to improve the
soil as well.

Jen

On 18 Sep 2005 08:32:04 -0700, sarab wrote:
The berm is totally covered in a very common weed here in NC - looks
like bamboo/grass, easy to pull, grows 2ft tall or so. Just mowed it
down, but was wondering if I could kill the weed seeds by covering it
now w/ black plastic until next May.

Quite doubtful. If you're willing to forego a year's pumpkin growing, you
can solarize with clear plastic, but unless you think you can get the
soil temp up to about 140oF this winter, you're not going to do yourself
much good. (BTW, don't cultivate the soil after solarization, you'll bring
up viable weed seeds from 6" or so down.)

FWIW, clear plastic works much better for heating the soil; black plastic
really just keeps light out, and it's expensive and messy compared to a lot
of other mulches.

Is the weed you're trying to control annual or perennial? If it's an
annual, I'd just dig the bed over now and in the spring, then use a light-
occlusive mulch when you plant your pumpkin seeds. Cardboard is great
for this; it's a nice clean mulch, so helps control some soil borne diseases,
helps keep the soil moisture even, and you can dig it in next fall with
no muss, fuss or bother. g

If it's a perennial you're trying to control, it's best to identify the
problem. Sometimes breaking up a perennial weed with cultivation is the
wrong thing to do... things that have "runners" like quackgrass or nutsedge
just start new plants from broken bits left behind in the soil. Or they'll
"hide" under your mulch and send out new plants just beyond the mulch. Other
perennials are relatively easy to control with a good digging-over of a plot.

Kay

Note that something like bamboo can easily penetrate a clear plastic.

Kay Lancaster wrote:
...FWIW, clear plastic works much better for heating the soil; black plastic
really just keeps light out, and it's expensive and messy compared to a lot
of other mulches....

Kay Lancaster wrote:
Is the weed you're trying to control annual or perennial? If it's an
annual, I'd just dig the bed over now and in the spring, then use a light-
occlusive mulch when you plant your pumpkin seeds. Cardboard is great
for this; it's a nice clean mulch, so helps control some soil borne diseases,
helps keep the soil moisture even, and you can dig it in next fall with
no muss, fuss or bother. g

The weed in question is almost certainly Japanese stiltgrass
(Microstegium vimineum). It's an annual. Using a layer of mulch
around the pumpkin plants will minimize the germination of the
stiltgrass seeds, and any seedlings that do appear are very easy to
weed out, due to the weak roots.

Cutting the existing stiltgrass now will prevent it setting seed.
Repeat the mulching, weeding, and late season cutting for several years
to get rid of dormant seeds in the soil.

On Wed, 21 Sep 2005 06:43:24 -0400, dps wrote:
Note that something like bamboo can easily penetrate a clear plastic.

Also black plastic, wood, asphalt, concrete... depends on the species
of bamboo being grown.


Kay Lancaster wrote:
...FWIW, clear plastic works much better for heating the soil; black plastic
really just keeps light out, and it's expensive and messy compared to a lot
of other mulches....