When to Plant Green Chiles in Phoenix, Arizona

Growing Season

• Green chiles are a warm-season crop requiring a long, frost-free growing period for best pepper production. Chiles are killed by frost, so they are grown as an annual during the frost-free months of the year. In Phoenix, green chiles have a long growing season, with the last spring killing frost usually occurring during early February through the end of March and the first winter killing frost about Jan. 1 through Jan. 10. It takes about 75 to 80 days from seed to harvest for green chiles, so there is ample time for good green chile crops in Phoenix.

Plants from Seed

• Green chiles are put into the garden as young plants rather than direct seeding them. Raise your own seedlings by starting them indoors six to eight weeks before they can go out to the garden. Plant seeds 1/4-inch deep in nursery containers filled with well-draining potting mix and provide a germinating temperature of between 80 and 85 degrees Fahrenheit, using a propagating mat if necessary. Give seedlings a sunny western or southwestern windowsill. Transplant seedlings to individual pots when they have two sets of true leaves. Before putting them in the garden, gradually get them acclimated to outdoors conditions.

Transplants

• You can also purchase started plants from nurseries or garden centers. Choose robust plants with healthy root systems that aren't root bound. Don't choose seedlings that have become leggy due to too little light. Look for compact growth and good leaf color. Set plants in the garden 12 to 24 inches apart, with the rows of plants 24 to 36 inches apart. Again, gradually ease plants from nursery conditions to their final place in the garden. If cold weather threatens the seedlings, cover them with floating row covers or frost blankets. You can grow green chiles in containers, bringing them inside to a protected location during cold weather, which will not limit you to set planting dates.

Transplant Times

• In Phoenix, which is in U.S. Department of Agriculture plant hardiness zone 9, transplants can be set out as early as February 15, with the period extending to March 15 for spring planting. Because of the long growing season, you can also put transplants into the garden from July 1 through July 15 to get a second crop before freezes may occur. Be guided by local weather conditions, delaying planting out if cold fronts are occurring at the marginal ends of recommended transplant times.