Arizona features both barren desert and highlands, and this means multiple climate zones. In much of Arizona, the state's summer temperatures climb well into the triple digits. Still, you can successfully grow grass on your Arizona lawn. You simply need to follow a few key guidelines, and one of the most important factors involves when to plant grass seed. Grass seed achieves maximum success in Arizona when it is planted during the best time of the year.

Considerations

Arizona's weather requires you to plant two kinds of grass seed. One performs well in the summer heat but goes dormant in the colder months. The other is a perennial that does well in colder temperatures. Each must be replanted each year when your warm-weather grass is almost ready to begin its dormant period. Each must be planted from seed at different times of the year. Therefore, you need to factor both into your seed application plans. You also need to understand your climate zone. If you live in the desert, you should plant earlier in the spring and later in the fall than someone who lives at a higher elevation, where cold weather could damage seeds before they germinate.

Fall Grass Seed

In the fall, plant tall fescue and perennial rye grass seed in preparation for it to grow through the winter months. These grasses do well in Arizona's winter climate, when Bermuda and other warm-season grasses go dormant. Perennial rye grass dies out in warm weather, particularly when Bermuda grass wakes from its dormant period and takes over your lawn. Therefore, you need to replant perennial rye grass each fall. Target your planting of these grasses for mid-September to late October in desert areas and for August in higher elevation areas such as Flagstaff and Prescott. You can overseed rye grass in mid-October to mid-November. If you plant it too early, the heat of the sun's strong rays can destroy the seedlings. As well, Bermuda grass will compete with the new rye seedlings if you plant the rye grass seed before Bermuda grass begins to slow its growth. You also must consider that planting rye grass seed too near the cold winter weather might stop it from germinating. Therefore, avoid rye grass seed after mid-November, even during mild fall weather. A single cold snap can destroy the seedlings.

Summer Grass Seed

In late and early summer, you'll want to apply Bermuda, nut grass, buffalo grass or centipede grass seed on your lawn. First, follow some key steps to kill off any perennial rye grass still living. Wait until the rye grass is dead before planting Bermuda seed. You also want to trim your grass to less than an inch in height before reseeding a Bermuda lawn. The best time to plant Bermuda grass is in May, June or July if you live at desert elevation. This allows the seed time to germinate before the arrival of the hot summer weather. Wait until after May 15 to seed. If you live at a slightly higher elevation, wait until June 1. Do not overseed Bermuda grass until its second year The grass seed takes 2 weeks to emerge.