Dear members, It was interesting reading the discussion about Roundup last week. I have a similar problem: pernicious weeds. I live in a townhouse alongside some birch trees. As you may know, a single birch produces millions of seed each season – every one viable! Birch seed seeps in through the tiniest cracks; it gets into everything: bedding, rugs, toweling, pet’s hair; it forms windrows in the driveway. My pots get covered with a “mulch” of viable birch seed. The second most pernicious weed is Stellaria media. I’m always amazed at how much of the stuff I have to pull out of every pot. Then there are the grasses and mustards …. So you can see, I’d be very interested in finding a commercially available chemical or hormone that would prevent seeds from germinating but which wouldn’t affect the growth of bulbs, whether they be dormant, awakening, or in full leaf/bloom. Thank you, David Ehrlich