Crabgrass is an annual weed germinating between March to June when soil temperature reaches 55 degrees. Improper watering practices and mowing too closely encourage crabgrass infestation. Seed heads appear from July to September producing thousands of seeds, giving rise to an increased population of new plants the following spring and summer (courtesy: grasspad.com).
By: John Green- Certified Texas Expert Gardener, Orange, TX
What a great start to the work week this past week as it began with significantly lower morning temperatures during the first half of the week! Many people (me included) are ‘anxious’ about returning to work on Mondays since this workday in particular quickly becomes convoluted (always, always, always) with harried, unpredictable demands when compared to other workdays…such as Friday! Having the work week commence with seasonably cooler temperatures with lower humidity somehow reduces my Monday morning ‘apprehension’ for the return to work and calms me somehow. Perhaps it’s all about perspective… perhaps not, bring on seasonal changes, as this gardener is ready!
Expanding on one of last week’s subtopics: Lawns– it’s time to show the lawn some “love” and provide much needed attention this month. September is the month to control perennial weeds, so let’s discuss wintertime weeds in more detail and how best to manage them.
As soil temperature cools, gardeners can utilize preemergence herbicide applications to eradicate many common cool season weeds. Turfgrass specialists recommend applying the correct preemergence herbicides to lawns now, as they can disrupt the germination (emergence) of many weeds in the spring. Fall preemergence herbicide lawn treatments will edit many weeds including annual bluegrass, rescue grass, and broadleaf weeds (henbit, chickweed, Carolina geranium & burweed). Gardeners should read and follow herbicide product labels completely to avoid injuring other plants in proximity.
Preemergence herbicide active ingredients will need to be considered before application! The preemergence product label will list plants which the product will control (perennial, annual, and broadleaf). Preemergence herbicides are most effective on annual weeds, whereas other weeds must be controlled utilizing post-emergence herbicides. Identifying weeds which are to be controlled is important to ensure the correct herbicide is selected. My recommendation, use granular herbicides for ease of application. It is important that gardeners have knowledge of seasonal and enduring weed populations to determine product selection. Selecting the correct active ingredient, then applying it properly are important aspects of weed management and control.
Turfgrass specialists recommend using a fall preemergence herbicide regimen when the soil’s temperature is approximately 70 F degrees which is based on annual bluegrass germination (germinates when soil temp is below 70F), which means that for gardeners in SETX this typically begins sometime in September. Our environment is ever changing and with that conditions can be considerably different year by year, which means some weeds will germinate later in the season. Build a preemergence program by applying products in a timely manner to stay ahead of weeds. Application of a preemergence herbicide, once in the spring and again in the fall will significantly diminish annual weed populations, if applied correctly.
Watering in the preemergence herbicide immediately after application. Usually, granular preemergence products require at least ¼ to ½- inch of water to suitably dissolve, though it is important to always follow product label instructions. The watering step can be easily accomplished using an in-ground irrigation system or a garden hose with sprinkler attachment. Attempting to align with rainfall is risky. Note: herbicides are not always 100% effective in our locale often due to heavy rainfall or less than desirable timing.
Weed & Feed
Weed and feed fertilizer/ herbicide products are popular products, but I don’t recommend using them as a turfgrass management tool, particularly for fall and winter. Our locale will soon be entering a period when warm-season grasses are not growing as quickly , slowly becoming dormant, meaning that it’s too late in the season to fertilize them. Applying nitrogen based fertilizers would promote growth, which would make turfgrass susceptible to significant damage when cold weather arrives.
It is a good time to walk about landscape and garden areas now (with camera in hand and note pad) to scrutinize the lawn and garden areas for summer weeds such as crabgrass, sandburs, goosegrass, nutsedge, spotted spurge, cocklebur, pigweed, and morning glory. These weeds thrive in the hot, humid SETX climate. To manage them, identify the type of weed (grass, broadleaf, or sedge) and use the appropriate herbicide, as some weeds are annuals (like crabgrass), while others are perennial and much harder to control (nutsedge).
Take pictures and write notes corresponding to problem areas (this eliminates guessing where the problem areas are) of existing weeds and assist you in preparation for spring preemergence application. Take the time to research and identify the weeds (using photos taken) and specific locations throughout the landscape.
Create an action plan to eradicate weeds from the lawn and establish management control tool to have warm season grasses off to a good start in the spring. Spring preemergence applications normally begin when soil temperature reaches approximately 50F degrees, and for us that typically begins somewhere between January and March.
Turfgrass requires adequate moisture going into winter’s dormancy, but once temperatures tumble, the amount of water provided should be curtailed. Turfgrass lawns need approximately 1-inch of rainfall or supplemental water per week when actively growing during summer months. During the fall season and winter months, rainfall is normally adequate. The soil needs to have a bit of moisture during winter months, as this offers turfgrass protection when hard froze occurs.
So long for now fellow gardeners! Let’s go out and grow ourselves a greener, more sustainable world, one plant at a time! Gardening questions answered: jongreene57@gmail.com.
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