Posted: 12/09/2012 at 12:42
Supernoodle, "Oh dear" your compost will never reach the temperature to kill those weeds and the slightest bit of it will be off at the gallop if you put it back on the soil.
I am afraid some hard work, bag it all up until you are sure you have all the weed and give it to the green waste their heaps are big enough to get up to the heat required, at least it will not be going to landfill.
Start again with your heap remembering you need Heat Air and Moistness to set a compost off composting properly. Start with some brushwood at the base to let in the air build up in layers with not too much of any one material, thin layers of each mixed with paper, cardboard, lawn or grass cuttings (never more than one inch of those) some woody stems and soft stuff such as dead headings. You can add some of the soil from old pots again in thin layers and damp down with a watering can as you go, DO NOT SOAK just a gentle spray from the can rose as you layer.
Turn out the heap every few weeks re-mix and toss it back, you will have pure gold in six months.
Sorry about the cure, one session of hard work will rid you of future problems and far better a little work now than hard labour later.