It’s that time of year for getting questions about weed control and fertilization in lawns.
Lawn fertilization and knowing how much and what type is key. But with COVID-19 affecting our lives so much, the university laboratories we depend on to help us with fertilization are practicing social distancing with employees, which can affect the timeliness of the results getting back to you.
Every research-based article states the general recommendation is a 3:1:2 ratio fertilizer. One example of that ratio would be a 15-5-10 fertilizer.
Behind the three numbers is nitrogen, phosphorous and potassium. Those three are the most needed of the 16 nutrients required for a plant to grow.
Nitrogen makes plants green up and promote growth, key for lawns. Phosphorous is great for seed germination and flower development. Now, phosphorous is a vital nutrient but turfgrass doesn’t need to germinate from seed and certainly doesn’t need to bloom. Potassium, the last of the major three nutrients, helps with root development and is a close second to nitrogen for overall lawn health.
The next question is how much to apply. The simple answer is seven pounds of 15-5-10 per 1,000 square foot. Do this three, maybe four times a season. The first application should occur after complete spring green up in April or May. So now is the time to get that out. An easy way to remember the following applications are every four to eight weeks or around these major holidays — Memorial Day, Independence Day and Labor Day.
Technically, St. Augustine needs two to five pounds of nitrogen per 1,000 square foot each year. Because nitrogen is a highly mobile nutrient, divide the application rates up to keep it available for the plants as they are growing.
So, what about “weed and feed” products?
To get the best looking yard possible, treat for weeds when you need to get rid of weeds. Fertilize when it needs feeding.
Most every weed we have blooming or going to seed now is a “cool season” plant.
“Cool season” weeds germinated and started growing last fall and during the winter. They are the weeds that you may notice are blooming now. The timing for their control was last fall. This fall, about October or November, is when you’ll treat for the next spring’s weeds.
Many of these cool season weeds will be gone by summer. That will be the time for our warm season weeds to germinate and grow.
For indepth information on weeds, there is an outstanding fact sheet for homeowners that just came out last year from AgriLife Extension. In your search engine, type ESC-055 or “A Homeowner’s Guide to Herbicide Selection for Warm Season Turfgrass Lawns.”
Lastly, is your sprinkler system running? If so, I’d probably turn it off. Overwatered lawns in the spring are prime targets for fungal disease. Watch the weather and add water when we have an extended dry spell. Summer is a great time to add water regularly to lawns. Anyone with the automatic system applying water three times a week now, may be hurting their lawn more than helping it.
I hope this year’s lawn is your best one yet. Timing the weed control, the addition of nutrients and your watering regimen correctly will greatly impact your success.
