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Pre-emergence Herbicides

A pre-emergent is a tool to prevent weeks from germinating in your lawn or garden.  Why bother with a pre-emergent?  Established weeds are more difficult to get rid of.  It is time consuming to pull weeds by hand once they are established or to treat them with a post-emergence herbicide.

Early March is the best time to apply pre-emergent blockers in this area.  They need to be applied BEFORE the seeds germinate.

It is important to be familiar with the growth cycle of each weed you want to eliminate.  It needs to be applied before the target weed germinates but not so far before that it loses its effectiveness.

Don’t apply pre-emergents on areas that you want to re-seed.  If you apply it to an area you will need to wait a few months before re-seeding.

There are two main types of pre-emergents.  Barrier controls used on areas that are not subject to a great deal of disburbance and those that can be used on soils that experience disturbance such as a walking path.






Preen Garden Weed Preventer Plus Plant Food


This product will not kill weeds, it prevents weeds from sprouting.  Rain will not wash this product away.

Barrier Control - Not appropriate for areas that will be disturbed during weed germinationn period

Most common weeds
















196 Moraga Way Orinda, CA 94563 Phone (925) 254-3713     Fax (925) 254-9168
Hours: 8:30-5:00  Every Day!    info@mcdonnellnursery.com

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