The right fertilizer at the right time improves the vigor of a lawn, fortifying it against disease, insects, and environmental stress. It’s an absolutely critical part of your lawn maintenance and landscaping in Houston. For the best results when you fertilize your lawn in Houston, it’s important to know when to apply fertilizer, how often, and what quantity to use.
Here are a few general guidelines to starting your Houston fertilizer schedule, but your Houston lawn may benefit from a customized program to suit the conditions and your own preferences.
What You Need to Know Before Fertilizing
A soil test can help identify what nutrients the lawn needs, but if you haven’t tested the soil, use a complete fertilizer with a 4-1-2 ratio of nitrogen, phosphorus, and potassium, such as 16-4-8. The ratio and nutritional analysis are printed on fertilizer bags.
You also should know the size of the area that’s being fertilized so the fertilizer can be applied at the appropriate rate. When too much fertilizer is used, the plants’ energy will be spent on leaf growth instead of root development. Grasses need to have strong, established roots before summer heat sets in.
It also helps to know what kind of grass you have. In Houston, as well as other parts of Texas, warm-weather grasses that suit the climate are planted, but fertilizer programs can be slightly different between species. It can also be very helpful to know when to plant grass in Houston to get the best results for your lawn.
Most lawns in Texas are composed of warm-weather grasses that originated in tropical regions, where they evolved to withstand high temperatures and full sun. Warm-season grasses grow mostly in the summer when the temperature is between 75 and 90 degrees Fahrenheit. In late fall and winter, when temperatures are cooler, warm-weather grasses go dormant and turn brown.
The warm-season grasses grown most commonly in Houston and elsewhere in Texas are:
- St. Augustine grass
- Zoysia grass
- Bermuda grass
Zoysia grass withstands cooler temperatures more than St. Augustine and Bermuda grasses, though it will go dormant eventually.
Fertilizer requirements differ for each type of grass, which will affect the lawn fertilizer schedule. Bermuda grass, for example, typically needs more nitrogen per year than Zoysia grass or St. Augustine grass.
Environmental conditions also affect when to fertilize grass in Texas. Fertilizing should be less frequent for grass growing in moderate to heavy shade, where root systems tend to be weaker. The different shade trees in Houston may prevent your grass from needing much fertilizer at all. Fertilizing too much will only weaken the root system further, making it more vulnerable to diseases and stress.
Lawns in areas with high rainfall need more nitrogen per year than dry areas. Fertilizer also needs to be applied more frequently for grasses growing on sandy soil than those growing in clay soil.
Another consideration is the desired outcome; if you want a lush, green lawn, you might want higher amounts of nitrogen. That also increases the frequency of mowing, so those who want to minimize lawn maintenance may want nitrogen to be applied at rates on the lower end of the recommended amount.
When to Fertilize Your Houston Lawn
The Texas fertilizer schedule for St. Augustine and Zoysia grass starts after the second mowing of the lawn for the season — usually about six weeks after the last frost — when the grass is actively growing and will utilize the nitrogen quickly. Several weeks after complete green-up is when to fertilize Bermuda grass in Texas.
Between June and August, continue to apply fertilizer every four to eight weeks, not exceeding the recommended limit for nitrogen for the type of grass and site conditions.
After the end of August, nitrogen fertilizer isn’t applied to lawns in Texas; however, if soil tests report potassium deficiencies, potassium can be applied, using muriate of potash (0-0-60), potassium sulfate (0-0-50), or another recommended source.
Keep in mind that Houston lawns may have particular conditions that require variations of a standard Texas fertilizer schedule, such as periodically supplementing nitrogen with iron to promote greening without weakening the grass.