weed and feed vs pre-emergent

Asked April 23, 2018, 11:07 AM EDT

hi, could you help me to understand if there's a difference between weed and feed vs. pre-emergent? i want to use pre-emergent for the Japanese stillweed that invades much of my yard. If i put pre-emergent down, however, i don't want it to kill the ferns that are there. Does pre-emergent kill everything? also will either the weed & feed or pre-emergent blow into my vegetable garden? thank you.

Harford County Maryland

1 Response

Most spring pre-emergents you see for sale are actually crabgrass pre-emergents. Crabgrass pre-emergents can also control stiltgrass. They should be applied about a week earlier for stiltgrass (Crabgrass is applied when the forsythia blooms are fading/falling.) Here is information about crabgrass pre-emergents: http://extension.umd.edu/sites/extension.umd.edu/files/_images/programs/hgic/Publications/non_HGIC_F...
Search 'stiltgrass' on our webpage for the correct one to use.

Crabgrass pre-emergents are formulated for grassy weeds (for the main part). They will not damage ferns. However, you should always read the label carefully.

Weed and feed, on the other hand, has fertilizer plus herbicides for crabgrass or broad-leaved weeds. Read the label to determine which weeds it controls. (It will probably not mention ferns.)
We do not recommend using weed and feed products in early spring (fertilizing lawns should be done in fall. And if not fall, then wait and do a 1/2 strength application in mid-May.) Over-fertilizing in spring can contribute to weak lush growth susceptible to fungal diseases.