Vegetables are divided into two groups warm season and cool season. Cool season vegetables, like their name implies, thrive when planted so they mature when temperatures are cooler. In Phoenix this means they should be planted at the end of summer or fall.
Cool season veggies can tolerate short term frost, so if the weather dips in January for a short period of time your cool season veggies will be ok.
If it is 40-50 degrees outside cool season vegetables can germinate. They prefer the soil temperature to be around 60 degrees. If the temperature is too warm, cool season plants will have a bitter taste or they will bolt (go to seed too soon).
Grow Cool Season Vegetables in Phoenix
Visual guide to planting cool season vegetables and fruits in your Phoenix garden. Some of our favorite cool season vegetables include: broccoli, carrots, onions, radishes, lettuce, and snap peas.
Plant Broccoli August 15 – January 15
Plant Carrots August 15 – April 15
Plant Lettuce August 15 – February 1

Grow Lettuce
Plant Peas September 1 – February 15
Plant Onions August 1 – April 15

Grow Onions
Plant Radishes September 1 – April 15
Plant Beets