Spring is Right Around the Corner: Put the Fertilizer Spreader Away...for Now

by Brad Voss, M.S., Texas A&M AgriLife Extension Service, County Extension Agent

Spring is just around the corner, but remember, our lawns are still just waking up. There might be some green sprigs in our yards, but it is still too early to fertilize. So, leave the fertilizer spreader in the garage and let’s talk a bit about early spring lawn care in North Texas.

Soil testing! Should you do it? Yes! Fertilization should be based on a soil test. We know our lawns will need supplemental nitrogen; grasses are heavy nitrogen users. However, we should only apply phosphorus and potassium if the soil test indicates a deficiency. Applying additional nutrients when none are recommended is not only a waste of money and time but could inadvertently harm the environment. Excessive nitrogen and phosphorus runoff into waterways can cause an explosion of vegetation. As this mass of excessive vegetation decays, it can suck the dissolved oxygen out of the water, leading to fish kills. Certainly not a good deal! Costly for you and costly for the environment. Conduct a soil test, then fertilize per the results.

Soil testing resources, including submittal forms and sample bags, are available at your local County Extension Office. The actual testing of soil is conducted at the Texas A&M AgriLife Soil, Water and Forage Testing Laboratory in College Station. Your test results will be emailed back to you. You can request a hard copy mailed to you for a small fee. Contact your local County Extension Agent if you need help interpreting your soil test results. We are here to help you.

When should the first fertilizer application go out for our warm-season grasses? The lawn will tell you when it is ready to use the nutrients in your fertilizer. Do not apply fertilizer until the lawn is actively growing and has been mowed two to three times. Generally, this falls in mid-April for North Texas, sometimes as late as early, early May during a cold spring. Avoid rushing this first feeding. Remember, soil temperature, not air temperature, is the primary driver of plant growth. Once soil temperatures reach 60-70 degrees Fahrenheit, you should start to see green up, depending on your grass species. Hold off fertilizing until you’ve needed to mow your lawn two to three times (actually needed to mow…not knocking down the weeds).

This brings us back around to soil testing. Rather than fertilizing too early, use this time to send a soil sample for analysis. The tests are inexpensive and can save you money and headaches in the future. In addition to the potential runoff and water degradation, excessive nutrients can fuel fungal diseases. Another key resource for fungal pathogens is moisture, and when does North Texas tend to have moisture? In the springtime, when it’s nice and mild, perfect for fungi. Adding excess nutrients to a lawn that’s not ready to use those nutrients could kick off a fungal infection. More money and time down the drain.

So be patient, we’re almost to full-blown lawn season, but don’t rush it! Conduct a soil test, fertilize appropriately. Stick to mowing as needed, following the 1/3 Rule and avoiding mowing when wet. Take a trip to the Aggie Turf website and read through some of their excellent fact sheets and guides. There is loads of helpful information there to help you build a beautiful and resilient lawn.

 

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What’s in the bag?

N-P-K, nitrogen, phosphorus, and potassium. Always in this order and always the first three numbers. Any numbers beyond could be any nutrient; check the label to find out. This is the fertilizer grade and represents the concentration of nutrients in the fertilizer. The bigger the number, the higher the concentration (more nutrients per pound of fertilizer).

Nitrogen: most lawn fertilizers will contain a mixture of readily available (quick-release) nitrogen sources and some slow-release nitrogen sources. These slow-release forms could be, just that, a form of nitrogen that must be converted to a form usable in the soil, or some type of coating on the granules (called prills) that takes time to weather away. This mixture of quick- and slow-release nitrogen sources allows products to feed right away and provide nutrition early on while still offering prolonged feeding. Could you use a product with little to no slow-release nitrogen sources? Yes, but you would need to apply fertilizer more often AND in smaller amounts. Having more slow-release forms of nitrogen allows you to fertilize less often, reducing workload and hassle. Most lawn foods contain a blend; don’t overthink it.