|I have phlox planted as a border...however, it seems that the weeds snuff them out.
I need to know a good weed killer, that willl get rid of these weeds, so the phlox can be brilliant and attractive, please?
|This is a common dilemma in perennial gardening. Grass and other creeping weeds (I'm particularly plagued by sheep sorrel) manage to work their way into perennial plantings and happily intermingle in the nice soil.
There are weed preventers such as Preen and organic corn gluten meal that can help prevent broad-leaf weeds from sprouting in the first place. These are granular products that get scattered right over perennials in early spring and then again 10 weeks later for season-long control. They don't hurt most existing plants (read the label for exceptions), but then again, they don't control 100 percent of the weeds. In particular, they're not good at preventing grass and grassy weeds.
Garden centers carry a few liquid products that kill grass and grassy weeds without harming perennials and shrubs around them. You have to use these chemicals very carefully because overdoing it can stunt or harm the "good" plants. I'd suggest testing it in a small area first before spraying a whole patch. These also are most effective when the grass is young. Fertilome Over The Top Grass Killer is one product. Be sure to read the label. Phlox should be one of the plants listed as safe to use around.
My opinion is that it's best to just dig up weed-entangled perennials, remove the grass and other weeds from the clump, and then replant the "cleaned-up" perennial. It's best to do this when the plant isn't in bloom. While you've got clumps dug up, that's also a good time to divide them. If you've got this problem all over, work on cleaning up the bed one area at a time.
Edging your beds once or twice a year will help keep grass from sneaking its way into the perimeter of your beds. Keeping an inch or two of mulch over the bed will help prevent grass and grassy weed seeds from blowing in and rooting.