Can anyone offer any suggestions on how to kill off any seeds dispersed
within home-made compost?

I have a large compost heap made from weeds and long grass, among other
things, and probably contains a lot of unwanted seeds. The large heap is
now about three months old and has been turned twice. Perhaps some of the
weed seeds have now been destroyed due to the heat generated within the
heap, but past experience causes me to suspect that many will not have been
killed.

I plan to use the compost to create a new lawn, using grass seed, in an
area where the soil is very poor. Last time I did this, the weed seeds
within the compost were prolific and started to sprout after the compost
was spread on the ground.

Thanks..

Al

On 11 Sep 2011 08:09:37 GMT, "AL_n" wrote:

Last time I did this, the weed seeds
within the compost were prolific and started to sprout after the compost
was spread on the ground.

Could you not spread the compost, leave it for a month, hoe off the
weeds and then sow the lawn seed.

I am in the middle of doing the same job, have removed the old lawn,
and while awaiting the ground to settle, (plan to turf in four of five
weeks) will be hoeing regularly.

New site in the making,
Lincolnshire Gamemakers for 2012
http://2012volunteer.co.uk/

On Sep 11, 12:57*pm, Janet wrote:
In article ,
says...



Can anyone offer any suggestions on how to kill off any seeds dispersed
within home-made compost?

I have a large compost heap made from weeds and long grass, among other
things, and probably contains a lot of unwanted seeds. The large heap is
now about three months old and has been turned twice. Perhaps some of the
weed seeds have now been destroyed due to the heat generated within the
heap, but past experience causes me to suspect that many will not have been
killed.

I plan to use the compost to create a new lawn, using grass seed, in an
area where the soil is very poor. Last time I did this, the weed seeds
within the compost were prolific and started to sprout after the compost
was spread on the ground.

* Your best plan is to prepare the new lawn bed, let the weed seeds
germinate,kill them off either with glyphosate or a flame gun, all before
seeding the grass. Some weed seeds will germinate later (sods law) but not
all kinds will survive regular mowing. *Any which do, you can either
winkle out with a pointy knife (my preference) or use a specialist lawn
weedkiller , but only when the grass is well established.

* I keep a separate dalek compost prison for seedy weed disposal; the
compost from it either goes into deep burial (like bean trenches) or as
surface mulch under shadyshrubs where seed germination will be minimal.

* *Janet

As you are only dealing with weed seedlings I would go for Wedol
rather than Glyphosate, Much quicker acting.

On 11/09/2011 09:09, AL_n wrote:
Can anyone offer any suggestions on how to kill off any seeds dispersed
within home-made compost?

Simplest solution is make sure your compost heap gets *really* hot above
70C will see of almost everything.

I have a large compost heap made from weeds and long grass, among other
things, and probably contains a lot of unwanted seeds. The large heap is
now about three months old and has been turned twice. Perhaps some of the
weed seeds have now been destroyed due to the heat generated within the
heap, but past experience causes me to suspect that many will not have been
killed.

I plan to use the compost to create a new lawn, using grass seed, in an
area where the soil is very poor. Last time I did this, the weed seeds
within the compost were prolific and started to sprout after the compost
was spread on the ground.

They will. Many are at least partially light activated and remain
dormant until they see light. Your best bet is incorporate it into the
ground leave enough time for activated weed seeds to germinate and then
hit it with a kill and deactivate weedkiller. Then sow your grass seed.

I'd be inclined to use commercial weed free compost or leave a fallow
period of 3-6 months to zap all the latent weeds if using own compost
with known weed seed problems. I tend to have the opposite problem of
compost heaps conflagrating leaving a small heap of ash. YMMV

Regards,
Martin Brown

Chris Hogg wrote in
:

On 11/09/2011 09:09, AL_n wrote:
Can anyone offer any suggestions on how to kill off any seeds dispersed
within home-made compost?

Simplest solution is make sure your compost heap gets *really* hot above
70C will see of almost everything.

But easier said than done. The only time my compost heap gets
noticeably warm is after I've dumped a huge amount of hedge clippings
on it. The rest of the year it's a few weeds here, a few prunings
there, and never enough at any one time to generate significant heat,
even though I occasionally water it with sulphate of ammonia to
encourage the bacteria.

I think my heap has been getting very hot at its core. I have the whole 5ft
x 5ft cylindrical, wire-netting-contained heap wrapped in a double-
thickness tarpaulin to help keep the outside surface moist and warm. The
outside surfaces are still, however, naturally going to stay cooler and
thats where most seeds will survive, I expect.

How long does it take for seeds to die due to old age? Probably a couple of
years, yes?

Al

On 14/09/2011 17:35, AL_n wrote:
Chris wrote in
:

On 11/09/2011 09:09, AL_n wrote:
Can anyone offer any suggestions on how to kill off any seeds dispersed
within home-made compost?

Simplest solution is make sure your compost heap gets *really* hot above
70C will see of almost everything.

But easier said than done. The only time my compost heap gets
noticeably warm is after I've dumped a huge amount of hedge clippings
on it. The rest of the year it's a few weeds here, a few prunings
there, and never enough at any one time to generate significant heat,
even though I occasionally water it with sulphate of ammonia to
encourage the bacteria.

The stuff they sell as something like Garrotta (sp? brandname) cut with
ammonium sulphate is fairly effective to initiate a hot heap. I don't
really do anything special these days since I have discovered that
provided you add at least 2m^3 at a time and do not squash it down the
thing will be mad hot inside within a couple of days. It smells a bit
funny - of short chain fatty acids so best off not near your house.

(even more true if it catches fire)

I think my heap has been getting very hot at its core. I have the whole 5ft
x 5ft cylindrical, wire-netting-contained heap wrapped in a double-
thickness tarpaulin to help keep the outside surface moist and warm. The
outside surfaces are still, however, naturally going to stay cooler and
thats where most seeds will survive, I expect.

How long does it take for seeds to die due to old age? Probably a couple of
years, yes?

Al

Unfortunately some weed seeds will live almost forever in the ground and
require exposure to sunlight to initiate germination. Common poppies are
a classic example of this - there are others.

Regards,
Martin Brown

Martin wrote in
:

I read once that seeds taken from ancient Egyptian tombs germinated.

Yes, I just learned about the 2,000 year old seed from Japan which
germinated and grew into a healthy flowering magnolia:

http://www.youtube.com/watch?v=yHFJ9...eature=related

I didn't have such succes with my 4-year old stock of vegetable seeds!

Al

Depends what they were! The umbellifers don't last much beyond a year, and that covers parsnips, carrots and parsley for a start.

Peas and beans generally keep for several years.

A lot of us keep seeds in the fridge, which seems to prolong life.

AL_n wrote:
I read once that seeds taken from ancient Egyptian tombs germinated.

Yes, I just learned about the 2,000 year old seed from Japan which
germinated and grew into a healthy flowering magnolia:

http://www.youtube.com/watch?v=yHFJ9...eature=related

I didn't have such succes with my 4-year old stock of vegetable seeds!

Quite impressive. I guess Egyptian tombs are designed to have good keeping
properties.

My out-of-date seeds are a bit hit and miss. Carrots, parsnipis, scorzonera
and cape gooseberries are all rubbish at germinating once they are anywhere
near their date. But I have a packet of beans that my neighbour gave me
when we moved in, and they were already out of date, and they still grow
each year! (I think I may have finished the pack last year, actually)
Iirc, they were dated 1999! (we moved in late Oct 2003)