How to kill off any seeds in home-made compost?

 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

 

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/

 says...

  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:

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

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