Hello! I have several large perennial gardens with bee balm, catmint, lillies, coneflowers, asters, hot lip turtle-heads, tons of hostas, etc...my wood mulch keeps out much of the weeds, but middle to late summer requires much weeding. How can i keep the weeds down early? If I apply a pre-emergent this week prior to the emerging plants, will that damage them or kill them? OR Do I wait to apply pre emergent until all the perennials are out of the grown growing? Thank you! Linda
Hennepin County Minnesota
You can apply a pre-emergent now without damaging the perennial flowers. However, weeds that are already established will not be affected.
Also, bear in mind that seed germination of any plants (desirable or undesirable) in the treated area will be suppressed.