Some fertilizer products contain preemergent or postemergent
herbicides for weed control, usually crabgrass prevention or control
of broadleaf weeds.
When to use these products
- Use only when the lawn has a known weed problem, not every
time you fertilize.
- Apply when you have observed high numbers of weeds and are
sure treatment is necessary. With preemergent products, this
means relying upon weed populations observed the previous year.
What to watch out for
- Be sure the active ingredient in the product is one that will
control the weed species that is causing your problems and also
that the timing is right.
- It is useless to apply preemergent herbicides after target weeds
- Be aware that certain broadleaf herbicides, such as dicamba
(found in several weed-and-feed products) and triclopyr can be
absorbed by tree roots growing in lawns and may injure trees if
applied too close to the tree drip line.
- Precautions are always listed on the herbicide label.