The Q&A Archives: Weeds

Question: I have a variety of grasses and different types of weeds. What product should I use for FL lawns?

Answer: For a specific plan of how to control weeds in your lawn you need to note three things. You need to know what type of turfgrass you have. You need to know what type of weed you have and then you need to know what your control options are in your environment.

BROADLEAF WEEDS In general, there are two types of weed leaves: broadleaf and grassy. The flourishing chickweed I have in a backyard flower bed is an example of a broadleaf weed. Others include henbit, dandelion, spurge and wild onion. Broadleaf weeds are easy to distinguish in a lawn. After all, they?re not a grass so they must be a weed! Broadleaf weeds react differently than grassy plants to herbicides. That?s an important point to remember as you make your scheme.

GRASSY WEEDS The thin emerald leaves of annual bluegrass show in patches in my lawn. Contrasting with the brown St. Augustine, they are easy to spot. In summer, my neighbor notices the coarse grassy appearance of crabgrass, dallisgrass and bahiagrass in his fescue. Grassy weeds aren?t as noticeable as broadleaf weeds but if you walk your lawn regularly you?ll come to recognize what you want and what you don?t want there.

Weed control in bermudagrass occurs in two ways: by preventing the weed seed from germinating each year and by killing weeds that already exist.

Products known as pre-emergent weed killers are used to prevent weed seed from germinating. There are several different chemicals and products available. They differ in the kinds of weed seed they control and the length of time the product remains active.

Pre-emergents should be applied before the weed seed germinate. For summer weeds, Like crabgrass, apply the chemical in spring after night temperatures have been in the 60's for four days around the time forsythias bloom. For winter weeds, like annual bluegrass, apply the preemergent in early October. Most products need to be watered into the soil after application.

Other weed killers are used after the weeds have emerged. There are different products for grassy weeds, like goose grass and broad leafed weeds, like dandelions. Onions are considered a broad leafed weed. These post emergent chemicals are used when the weeds are actively growing, early in the summer.

When bermudagrass is completely dormant in January, a non-selective weed killer containing the chemical glyphosate can be used to kill fescue and other weeds. Make sure the bermudagrass is dormant and spot spray the green weeds.

It is important to know the name of the weed you are trying to control before using any weed control chemical. Once you know the weed, it is simple to read the label of a weed control product to see if it works on your weed. Also be sure to check and see if the chemical can be applied to your lawn grass without harming it. Never apply more of the chemical than the label recommends. Double doses of herbicide can kill your entire lawn before you know it.

« Click to go to the homepage

» Ask a question of your own

Q&A Library Searching Tips

  • When singular and plural spellings differ, as in peony and peonies, try both.
  • Search terms are not case sensitive.

Today's site banner is by Paul2032 and is called "Coreopsis"