ANT INFESTATION

you can use the soil as soon as you stop seeing the ants, but if the soil is old I would advise changing the compost anyway.usually ants like dry places so if the powder isn't effective i would give your soil a good soaking for a few days that should make them move on

I have had this problem all year on a school allotment I run.

Islander: soaking annoys them but it does nothing to budge them.

Yes, they can harm your plants but only indirectly. The little buggers get right into your plant pots and tunnel so that the roots have poor contact with the soil. I have lost many plants outdoors because of the incessant tunnelling. In addition, they will farm aphids, though this is less of a concern this time of year.

I have tried all sorts of home-made remedies as the garden is on a school playground. No luck. I am now using ant powder. I expect them to returm next year and start the struggle all over again.

Good luck and please let me know if you find a way to control them

^.^

The 'golden' ants are the ones that generally stay in the nest looking after the eggs etc. and the black ones are the 'workers' that go out and find the food. The only way I have found of getting rid of them is to locate the nest (where the eggs are) and destroy that by pouring boiling water in. If you just break up the nest then the golden ones will carry the eggs away and start a new nest somewhere close by.
Grousome I know but if you want rid of them.............