Will Preen Prevent Grass Seed from Germinating?

What weeds does Preen^® Garden Weed Preventer kill? None. Preen ^® Garden Weed Preventer helps to prevent germination of seeds from the list of weeds shown on the label for up to 12 weeks per application. It does not kill or inhibit existing weeds in any way.

Can you use preen with new grass seed?

Although chemical weed preventers have different mixtures and instructions, you should not apply them while seeding or immediately afterward. You must allow one to four months between applying this type of chemical and spreading seed.

Will preen stop grass seed from growing?

Preen is a pre-emergent weed prevention product. It prevents weed seeds from germinating instead of killing existing mature weeds. ... Preen only works by preventing seeds from germinating. However, Preen also makes a lawn weed control product that targets established lawn weeds.