Q. I’m in Southern California, and it is HOT here, I’m looking for some heat tolerant greens. I saw you have the Malabar Spinach and that’s supposed to be pretty good for zone 9/10… Do you have any recommendations of heat tolerant varieties lettuce, spinach, cucumbers etc. Anything else you can  recommend based on what you’ve seen growing in your garden?

A. Thank you for your patience in awaiting the list. 🙂 We took your requested varieties and expanded our search, deciding to make it a topic to share with all customers who live in extreme heat areas. Thank you for sparking this research! Below the lists, we also have added some links to articles you may find helpful, and some tips that are helpful when gardening in high heat. We hope you find this helpful. May God bless your gardening efforts!

Cucumbers that tend to do better in the heat are:

• Homemade Pickles
• Lemon
• Marketmore 76
• Spacemaster 80
• White Wonder

For lettuces, the most heat tolerant varieties we have are(but should still be planted outside the hottest part of the year in extreme heat climates) :

• Freckles
• Red Salad Bowl
• Simpson Elite

The other greens that do well( a couple of them you already know) are:

• Malabar Spinach(a climber, so make sure to trellis or plant near a fence)
• New Zealand Spinach
• Swiss Chard
• Arugula
• Mustard Greens – especially Green Wave (known for doing well in extreme heat)
• Collard Greens

Herbs that do well in the heat are:

• Basil ( see all our many basil varieties here)
• Cumin
• Rosemary
• Summer Savory

Pole beans also do better than most beans in the heat:

• Kentucky Wonder Pole Bean

Cowpeas do well in hot climates:

• Purple-Hulled Pinkeyed
• California Blackeye

Okra loves heat, having originated in Ethiopia:

• Clemson Spineless
• Red Burgundy

Eggplant does great in the heat, as well, coming from Asia and India where eggplant is the basis of many delicious recipes:

• Black Beauty
• Long Purple
• Florida Market

Tomatoes like heat, too, but some varieties don’t set fruit in higher heat conditions. These varieties tend to handle more extreme heat better:

• Arkansas Traveler
• Beefsteak
• Black Cherry
• Black Krim
• Brandywine Pink
• Cherokee Purple
• Floradade
• Mule Team
• Oregon Spring
• Stupice
• Super Sioux

Radishes can tend to do well in high heat, varieties that are known to be heat tolerant are:

• Early Scarlet Globe
• German Giant

Some beets stand well in more heat:

• Bull’s Blood
• Chioggia
• Detroit Dark Red

Many gardeners in extremely hot climates find summer squash/zucchini don’t do well in the high heat. A trick to try is growing moschata winter squash varieties and harvesting them early as a summer squash. You can also use the young leaves and shoot tips of squash for cooking greens. A great variety of winter squash to use as a summer squash is:

• Waltham Butternut

For veggies that love heat and all varieties should do well, we recommend:

• corn
• lima/butter beans
• peppers: both hot and sweet/bell(for best sweet pepper try California Wonder or Sweet Banana)
• melons, both cantaloupe and watermelons(particularly Crimson Sweet Watermelon. Keep the plants evenly moist but don’t overwater especially when the fruits are ripening. Too much water will dilute the sugars, making the melons bland.)

Other tips that are important for the heat of Summer, most especially in regions with the hottest summers are:

• Keep soil moist by mulching. A few inches of bark chip, wood chip, pine needles, or leaf mulch bagged in autumn are all good organic choices for feeding the soil as well as conserving water.
• Vegetables are thirsty, so water regularly yet deeply. Also, water in the early morning or evening to avoid condensation loss at hotter times of day.
• Remove competition for water by weeding regularly.
• Don’t overstimulate plant growth by fertilizing during hot weather. Plant roots won’t be able to support the foliage.

https://freckledcalifornian.com/2020/03/30/10-heat-loving-vegetables-and-flowers-to-grow-from-seed/

https://gregalder.com/yardposts/growing-and-harvesting-lettuce-in-southern-california/

https://www.gardeningknowhow.com/edible/vegetables/tomato/hot-climate-tomatoes.htm

https://www.lasfloresgarden.com/southern-california-planting-guide/