Question
I want to fill my flower bed with decorative  stones to stop the weeds.  I do have plastic down and I mulch every year but I still get weeds.  Can I stop the weeds by laying a layer of stones.  My hubby says NO.  And also what do I do about the periannuals I already have planted

Answer
Hi Polly,
Thanx for your question.  Weeds always have a way of finding the oddest places to grow.  Even between rocks.  Preen is a product you can use to keep down weeds as long as you are not planting seeds.  If there are existing perennial plants in the bed, Preen will not prevent them from growing but you can't sow seeds and put down Preen.  I hope this helps.
Tom