Lawn care calendar for Nevada: when to fertilize and seed

Watering rules change by season and by water provider, so confirm your assigned days with SNWA or TMWA before you set a controller.

Which grasses grow where in Nevada

The University of Nevada Extension places the middle elevations of the Mojave Desert, at 2,000 to 3,000 feet, in the transition zone, where either warm-season or cool-season grass can grow. Warm-season grass is best adapted to the heat: common and hybrid bermudagrass, zoysiagrass, buffalograss, seashore paspalum and St. Augustinegrass. The drawback is that they go dormant in cold weather, so some owners overseed with ryegrass, and bermudagrass takes that best.

Hybrid bermudagrass is finer, produces less pollen and stays green longer in fall than common bermudagrass. In Clark County, ordinances prohibit planting common bermudagrass because of its pollen. Zoysia tolerates desert soil and moderate shade and is mowed every 10 to 14 days, and St. Augustinegrass has the best shade tolerance of the warm-season group. In northern Nevada the lawns are cool-season turfgrasses, which stop growing in high heat.

Frost dates from NOAA

Dates are the NOAA 1991-2020 normals for the last spring and first fall 32 F freeze at 50% probability. At Las Vegas (Harry Reid International Airport, formerly McCarran) the last spring frost averages January 20 and the first fall frost December 15. At Reno-Tahoe International Airport the dates are April 20 and October 23, and at Elko Regional Airport they are May 29 and September 18.

Counting the days between them gives about 329 frost-free days at Las Vegas, 186 at Reno and 112 at Elko (our arithmetic). An Elko lawn has less than four months between average freezes.

Mowing and feeding

The university says that if you adopt only one lawn practice, it should be mowing at 3 inches or at your mower's highest setting. A tall lawn handles heat and drought, grows deeper roots and has fewer weed and pest problems. Mow often enough to take off no more than a third of the blade, and leave the clippings, which contain up to 5 percent nitrogen and do not make thatch.

Cool-season grass in northern Nevada stops growing in high heat, so do not fertilize in summer. UNCE says to feed no more than three times a year and to make the final feeding in September or October for a quick spring green-up. SNWA says the same in the south: fertilize in late September or early October with a balanced nitrogen, phosphorus and potassium mix, which improves root growth and color and builds cold resistance.

Watering rules

The Southern Nevada Water Authority limits landscape watering to three assigned days a week from September 1 through October 31, Sunday is never a watering day, and the limit also applies to drip irrigation. For grass it suggests three 4-minute cycles in the early morning rather than one long run, moving to several short mid-morning cycles as weather cools. Bermudagrass and other warm-season grasses use about a third less water, and adding or removing one minute from a 4-minute cycle changes water use by 25 percent.

The Truckee Meadows Water Authority assigns sprinkler days by address: even addresses Tuesday, Thursday and Saturday, odd addresses Wednesday, Friday and Sunday, and no sprinklers on Monday. The page I read asks customers to shut sprinklers off between noon and 6 p.m. from Memorial Day through Labor Day, and says drip and hand watering are allowed any day. Its water-and-wait method runs the sprinkler until puddles form, rests 1 to 2 hours, and repeats until the water reaches 6 to 8 inches.

Aerating, weeds and the grass law

Compacted soil is common in the Las Vegas Valley, and SNWA advises aerating in September or October with two or three passes of a coring aerator to at least 3 inches, after moistening the grass a day or two earlier. UNCE says northern lawns should be core aerated once a year, leaving the cores to break down, with a thin layer of compost on top. Spot-treat weeds with a selective herbicide and apply fertilizer separately; weed-and-feed products put herbicide on the whole lawn.

A 2021 Nevada law will bar the use of Colorado River water delivered by Southern Nevada Water Authority member agencies to irrigate nonfunctional grass from 2027. SNWA says it covers commercial, multi-family and government property, and does not apply to grass at single-family homes.

Fertilizer rules

Nevada Revised Statutes chapter 588 governs commercial fertilizers and agricultural minerals as products, with grade and labeling rules. I found no Nevada rule limiting phosphorus in home lawn fertilizer in it. UNCE and SNWA both point to timing and amount: no more than three feedings, none in summer.

The lawn fertilizer calculator on this site converts the nitrogen percentage of a bag into pounds of product for your square footage, which helps when a label gives its rate in pounds per 1,000 square feet.