If you're like many homeowners, the arrival of spring has the anticipatory effect of kid on Christmas morning. You walk out onto your front lawn eager to see the fruits of your hard, lawn maintenance labor: A swath of beautiful green grass as far as the eye can see.
But instead, you spy the virtual lump of coal -- or invasive blade. The one thing standing between you and the "Most Beautiful Yard" award: weeds.
You're flummoxed. It makes no sense. You did everything to protect your yard: scalping, aerating, mowing, even pre-emergent weed care. What can you do now?
The answer: post-emergent weed control
Here to provide an expert perspective on how post-emergence rescues and restores your yard from weed incursion is leading lawn care specialist, King Green.
You're Not Alone
First know you're not alone. As King Green explains: "It's not at all surprising to see weeds breakthrough pre-emergent barriers, especially perennial and noxious weeds."
The Big Three Weeds
For warm season turfs of Georgia and the southeast, three common weeds stand above:
- Plantain: The most predominant variety of weed, this large, broadleaf plant has dark green leaves, a netted vein, and lie close to ground in a carpet-like fashion.
- Clover: "Over and over," as the song goes. The good news: The presence of clover signals nitrogen-deficient soil, common near garden "feeders." Restore the nitrogen via various fertilization options -- blood meal, alfalfa meal, animal manure, fish emulsion, and so on -- and you eradicate the clover.
- Dandelion: Those white puffy bulbs are fun for kids to wish upon, but every time they get blown into the wind, they spread their seeds.
Other common varieties are grasses (crabgrass, dallisgrass, bluegrass, and sedges), chickweed, dead nettle, wild garlic and onion, and so on.
Your first method of defense for post-emergent weed control is removing the unwanted plants by hand or garden tool. The best time to attempt this is immediately following a good rain. However, this approach, while the most environmentally conscious, isn't always effective. In which case, King Green recommends the use of herbicides.
2 Kinds of Herbicides
When asked, "Can you kill the weeds?" the King Green team gives one reply: "Killing the weeds is the easy part. Killing the weeds without killing the grass is the trick."
Extreme caution and foreknowledge are essential when using the two available products:
- Non-Selective: King Green stresses: "These products destroy anything and everything green, whether they're weeds, your grass, flowers or shrubs." Recommended for use on warm season turf that is completely dormant, such as bermudagrass come winter.
- Selective: Controls a specific plant material without damaging others. Explains King Green: "You can use these to spray a dandelion in a fescue lawn and the dandelion will wither and die while the fescue remains unharmed."
The key is to know your weed. Every selective post-emergent product is meticulously formulated to match an exact specie, using a pre-measured, pre-calculated combination of funny-sounding chemicals (MCPP, MCPA, netazon, imazaquin, dicamba, et al). At worse, an improperly paired herbicide/weed will result in irreversible turf damage. Always, always READ THE LABEL!
Rules of (Green) Thumb
King Green dispenses the following guidelines to ensure effective post-emergent weed eradication:
- Timing: Try to avoid doing your weed control when it's too hot out (over 90 degrees). Ideal temperature range: Between 65 and 85-degrees, in the evening to give the products time to be absorbed prior to watering or mowing.
- Soil Condition: Adequately hydrated. Drought-stressed turf won't absorb treatment
- Air quality/precipitation: No rain in forecast for at least 24 hours. Mild, dry, and not windy, to avoid "herbicide drift" onto other ornamental plants and flowers.
- Maturity: Attack a weed as soon as it shows up
- Mowing: Don't mow immediately before or directly after application
- Number of applications: Might require multiple treatments, depending on severity of invasion
Note: For brand-new lawns in the first year of seeding and sodding, any weed treatment should be reduced to accommodate more vulnerable soil.