Warm Season Crops
The days are warming up and growing longer… you might even notice powdery mildew on your winter kale or see your lettuce bolt and turn bitter overnight. It’s time to transition your garden from cool season plants to warm season, spring and summer 2024 crops!
Warm Season Crops: When, Where, and Why.
San Diego County contains two USDA Growing Zones: 10 and 9, and in 2023 the USDA came out with an updated Plant Hardiness map you can learn about here. These areas have differing average annual minimum temperatures during the winter.
Zone 10a (higher average temperature): Coastal San Diego, from La Jolla to Imperial Beach
Zone 9 (lower average temperature): Desert regions west of El Cajon and Santee
The majority of San Diego is Zone 10a. Growing zones matter because they give suggestions on the ideal planting time. For example, Zones 9 and 10 have two basic seasons (hot and cool), but Zone 5 in Nebraska has a single growing season of April to October.
Your location within San Diego will determine the best time for you to start your new plants. For example, if you live in the warmer Zone 10, you can plant the warm season crops earlier. San Diegans living in easterly Zone 9 should wait for the warmer days of April to plant their tomatoes, etc. Find out the zone you’re in by entering your zip code at the USDA website.
Setting the Stage:
You can plant the spring and summer season crops listed below at any time during the suggested months, but consider starting them early to take advantage of the long growing season! Here are some tips to follow while you prepare your garden:
Refresh your garden bed: pull the spent plants (and if possible, compost them!) and fertilize the bed with organic vegetable fertilizer. Avoid fertilizer with a high nitrogen count (anything with double digits) because this creates an unnatural amount of quick, weak growth.
Try not to step on the bed, and avoid massive soil turnover in order to maintain the health of the soil ecology that’s built up in the cool months.
If you want to seed tomatoes early, it’s recommended that you do so indoors with heat lamps because they require 50-90 warm days (depending on the variety) to reach maturity. However, for a head-start and less headache, we recommend buying seedling starts instead.
Adjust irrigation settings to accommodate for longer daylight and warmer weather.
Growing food in San Diego and Orange County’s warm season is incredibly rewarding. Harvests are often heavy and varied, and you can bite right into the fruits of your labor!
What To Plant Now:
Beans: March-August
Corn: March – July
Cucumber: April – July
Eggplant: April – June
Lettuces: heat-tolerant only, preferably in the shade!
Melons: April – June
Okra: April – June
Peppers: April – June
Squash, summer: March – August
Squash, winter: April – June
Sweet Potatoes: April – June
Tomatoes: March – July
Potatoes: August – Sept