Weed Control

There is nothing you can do to prevent occasional weeds from appearing in even the best cared-for lawn. Wind-borne seed and seeds transported by animals and people will see to that. Nature, however, cannot be blamed for the existence of large weed patches or weed infestations throughout your turfgrass. Proper mowing, watering and fertilizing will correct most if not all weed incidences.

Two basic reasons for any sizable weed incidence are:

• Poor preparation of the site at lawn installation
• Neglect or incorrect turfgrass management

There are two groups of chemicals that will assist you in your lawn care and battle with weeds:

• Post-Emergents – just as the name implies, Post Emergents are chemicals that are used to eliminate weeds AFTER or post germination. 2-4,D and Trimec are two common and readily available products that are post emergents.
• Pre-Emergents – again as the name implies, Pre-Emergents are chemicals that are used to eliminate weeds BEFORE they germinate and become visible. Dacthal and Ronstar are two common pre-emergent products.

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There are two major groups or classifications of Weeds:

• Grassy Weeds - The appearance of this weed resembles grasses in that they are stout and smooth stemmed, are sheathed in long slim and often hairy leaves. Germination of these weeds occurs when day time temperatures exceed 80 degrees. In the south this can occur as early as March and in the North around June. Examples of this type of weed include barnyard grass, crabgrass, goosegrass and dallisgrass.
• Broadleaf Weeds - The appearance of this weed is synonymous with its name in that it generally possesses a distinguishable leaf, has weak and pithy stems, sometimes a showy flower and often a large tap root. Examples of this type of weed include dandelion, kochia, bindweed, lambsquarter and henbit.

Both types of chemicals will eliminate both types of weeds, yet there are times when only one type of chemical will eliminate a certain weed. For example: The dandelion seed can be prevented from germinating by applying a pre-emergent to your lawn. If however a dandelion plant is already growing there the pre-emergent will not harm the plant and in order to eliminate the dandelion, you will have to apply a post-emergent chemical.

The best insurance against any weed incidence is a healthy lawn that is properly maintained. As every lawn and landscape has thousands of tiny time bombs (weed seeds) hiding in the soil, a pre-emergent program can be an important part of this maintenance. To create a year long Pre-emergent Weed Barrier, you will need 3 applications. This applies to all turfgrass varieties:

Pre-Emergent Schedule

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• Depending on the pre-emergent chemical used, effective time periods may vary (some chemicals will provide control for 30 days and some up to 90)
• Grassy weeds are more difficult to eliminate and the pre-emergent application for them is critical for your lawn to remain weed free. Grassy weeds begin to germinate when daytime temperatures exceed 80, or 50 degrees soil temperature, so depending on where you are located this may occur in April, May or June. Your application needs to coincide with this temperature occurrence.
• Application 2 in the chart above can be applied (May-June-July) to Grassy and Broadleaf weeds, timing is important.
  

Post-Emergent Schedule

There is no recommended schedule for Post-Emergent Applications as they are done on an as-needed basis only.

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