What to Plant in August in Arizona

Are you wondering what to plant and harvest in August in Arizona? I’ll show you which seeds to start indoors and what you can plant outside in August. It is still hot in the Phoenix Valley, but if you want another round of warm-season crops, August is a good time to plant. It’s also an important month for starting seeds indoors.

For a printable checklist and information about August gardening tasks for the low desert, read this article. The low desert includes elevations below 3500 ft in the Southwest, such as the Phoenix and Tucson metro areas.

What to Do Before You Plant During August in Arizona

As you decide what to plant in August (and upcoming months) in your low desert garden, think about what you enjoy growing the most—what do you most look forward to in the garden? Which foods taste best from the garden? What do you love having easy access to?

Take a look at your available space. A significant planting window for cool-season crops will open in mid-September and October, so be sure to leave some room for them! 

• Prepare beds for planting (this post tells you how). Add compost, worm castings, and other organic matter to the soil.
• If your garden hasn’t been growing well, consider having your soil tested. I use this test kit from Amazon. Based on the soil test, add a balanced fertilizer if needed.  
• Take time to harden off your seedlings correctly so they can adjust to the heat. Learn more in this article.
• Provide extra shade and water for new plantings.
• For a printable checklist of garden tasks to do in August, read this post.

Want more information about gardening in Arizona? This blog post shares seven tips for how to grow a vegetable garden in Arizona. 

For August planting dates and easy succession planning, learn more about the Low Desert Garden Planner or buy it in my shop.

What Can You Harvest in August in the Low Desert of Arizona?

We can garden year-round here in the low desert, and it seems there is always something to plant and harvest. Weather patterns vary, and some years higher than average heat and lack of rain can make gardening more challenging. However, If you’re following my planting guide, here are some of the vegetables it’s possible to harvest during August. I’d love for you to leave a comment and let me know what you’re harvesting right now.

(click on the link to read “How to Grow” articles about each crop)

Vegetables:

Amaranth, Armenian Cucumbers,  Asparagus Beans, Beans, Borlotti Beans, Butternut Squash, Cucumbers, Eggplant, Malabar spinach, Okra, Peppers, Sunflower Seeds, Summer Squash, Tomatillos, Tomatoes 

• If you still have tomato plants hanging on after the summer heat, this guide to reviving and pruning over-summered tomatoes in Arizona can help you decide whether to keep them or start fresh.

Herbs:

Basil, Dill Seeds, Lemongrass, Lemon Balm, Lemon Verbena, Mint, Oregano, Parsley Seeds, Sage, Stevia, Rosemary, Thyme

• August is a good time to begin starting cool-season herbs indoors, and this guide on how to grow dill will help you time your plantings for a longer harvest.

Fruit:

Apples, Blackberries, Cantaloupe, Chichiquelite, Figs, Grapes, Ground Cherries, Passionfruit, Watermelon

Which Flowers Bloom in August in the Low Desert of Arizona?

It’s hard to believe anything can bloom in such hot weather, but several flowers bloom throughout the summer months. These blooms provide a bright pop of much-needed color during the heat.

(Click on the link for each flower’s “How to Grow” blog post.)

Possible blooms this month include amaranth, angelonia, basil, celosia, coreopsis, cosmos, four-o-clock, echinacea, gazania, gomphrena, lisianthus, portulaca, purple hyacinth bean vine, ratibida, rudbeckia, salvia, scabiosa, statice, strawflower, sunflower, tithonia, verbena, vinca, yarrow and zinnia.

What to Plant Outside in August in the Low Desert: Vegetables, Herbs & Fruit

By planting in August, you’re setting yourself up for a bountiful harvest of warm-season crops like tomatoes, squash, cucumbers, and corn, which can sometimes struggle because it gets hot so quickly in the spring.

(Click the link to read “How to Grow” articles on my website.)

After August 15

• Cucamelon (T)
• Cucumber (ST)
• Summer Squash (ST) 

SEED, TRANSPLANT, OR BOTH? S = Seed / T= Transplant

Arizona Vegetable Planting Guide helps you learn when to plant vegetables in the low desert of Arizona and whether to plant seeds or transplants.

Which Seeds to Start Indoors in August: Vegetables, Herbs & Fruit

If you’re serious about having strong seedlings ready for fall planting, now is the time to get to work. Choose a few favorites from the list below and start planting indoors. Need a refresher? Here’s how to start seeds indoors.

(Click the link for seed sources)

Ready to start planting? These are my favorite seeds and the companies I order from year after year. Here’s a link to my favorite seed-starting supplies on Amazon.

Flowers to Plant Outside in August in The Low Desert

• Purslane (ST)
• Sunflowers (S)

SEED, TRANSPLANT, OR BOTH? S = Seed / T= Transplant

Flower Seeds to Start Indoors in August

If you want a beautiful spring garden, now is the time to start those flower seeds indoors. A little effort now means blooms to enjoy when the weather cools down.

(Click the link for seed sources)

Arizona Annual Flowers Planting Calendar helps you learn when to plant flowers in Arizona and whether to plant seeds or transplants.

If you are ready to keep learning, explore my gardening classes available online and in person.

Make plans for planting roses this fall. Choosing the right varieties helps ensure your roses survive the summer heat.

I get all of my roses from Heirloom Roses. I love that they are own-root roses (no grafts!) and that they meet the highest standards for disease resistance. You know you are getting robust, disease-free roses with strong roots when you get them from Heirloom Roses. Use Code GARDENAZ26 for 20% off roses, perennials, and bulbs. Order roses now and have them shipped when you are ready to plant (up to 8 months later).

If this post about what to plant in August in Arizona was helpful, please share it.