The heat brings with it important garden tasks – mulching and providing shade are two of the most important to help the garden survive the summer.
Keep reading for garden inspiration, a May garden checklist, and a list of which vegetables, herbs, and flowers to plant in your low desert Arizona garden in May.
Low desert includes elevations below 3500 ft in the Southwest, such as the Phoenix and Tucson metro areas.

Disclaimer: This post may contain affiliate links. See my disclosure policy for more information.
What to do in your low desert Arizona garden during May

What grows in low desert Arizona gardens in May? I’ll show you. All of these pictures come from my garden in Mesa, Arizona. Although the temperatures are beginning to climb, May in the Arizona garden is one of the most beautiful and productive times.

“It was such a pleasure to sink one’s hands into the warm earth, to feel at one’s fingertips the possibilities of the new season.”
~ Kate Morton, The Forgotten Garden

Vegetables growing in the low desert Arizona garden in May


May is an excellent month for tomato harvests. Because of the heat of Arizona summers, we have a short growing season.
Tomato varieties highly recommended for Arizona include Punta Banda, Celebrity, Pearson, and Cherokee Purple.

Summer squash grows quickly. What is small one day is often ready to harvest the next day. Summer squash tastes best when small and tender. Harvest squash when fruits are 4-6 inches long.

Cucumbers grow best with a long warm (but not hot) growing season. To overcome the challenges of growing cucumbers in Arizona, the key is to plant cucumbers early in the season and plant short-season varieties, such as the Collier cucumber pictured here that will ripen before the hottest days of summer.

Harvest beans when they are small and tender. As beans mature, they lose flavor, and the pods begin to bulge with seeds. This signals the plant to stop producing.

Tips for growing flowers in the low desert Arizona garden in May


In Arizona, plant sunflowers from February through July to enjoy the blooms nearly year-round. Pops of yellow flowers brighten up a summer yard.
Learning how to grow sunflowers is an easy way to add color and variety to a summer garden and yard.


Hollyhocks put on a show in late April through June. Enjoy the prolific blooms. Save seeds to spread around your yard and share with friends.

Flowers to Plant Outside & Seeds to Start Indoors Each Month in the Low Desert of Arizona.
• PLANTING GUIDE: Each month lists annual flowers and bulbs to plant outside & seeds to start indoors.
• BLOOMING GUIDE: Photos show what may be in bloom that month.

Fruit trees in the low desert Arizona garden in May


Some varieties of apricots ripen this month. Pick them just before they are ripe to prevent the birds from getting them first.

May in Arizona means mulberry, blackberry, and strawberry harvests. To prevent strawberries from drying out, water strawberries regularly during May. Blackberries are sweetest when “dull black”.

The early-ripening varieties of peaches are often ready to harvest this month.
If you notice the birds are beginning to peck it, harvest the fruit a little early and let it continue to ripen on the counter.
Read this article for more information about how to grow peach trees.

Herbs in the low desert Arizona garden in May



Bay Laurel – Always dry bay leaves before using. The bitter-tasting compounds in the fresh leaves are lost in drying.

Lemon Balm (in the Mint family) loves the warmer temperatures of May. Hopefully, frost-damaged or woody growth was pruned in March, and new growth is filling in.
The new tender leaves are the most flavorful. Keep tips pruned to encourage production.
Arizona Garden in May to-do list:

Planting:

- Plant container-grown roses this month on the north or east sides of the yard that receives afternoon shade in the summer.
- It is ok to plant summer flowering shrubs. Do not over-plant; be aware of the mature size of the plant and space accordingly.
- Get warm-season annuals planted this month.
- Start seeds indoors this month for a monsoon planting of tomatoes.
- Harvest garlic and onions this month.
Watering:

- Do not overwater or underwater this month. Both are harmful to plants.
- Check the irrigation system and timer. Run the system, and inspect all drips and sprinklers for leaks and proper watering.
- As temperatures heat up, annual plants will need more frequent watering. Water to a depth of about 6 inches every 2-3 days; allow the top of the soil to dry out before watering again.
- Check containers with a moisture meter or ensure the top inch or so of soil has dried out before watering.
- Established citrus trees should be watered once every 7-10 days to a 2-3 feet depth.
- Water established fruit trees every 3-5 days to a 2-3 feet depth.
- Grape vines need deep watering every five days.
- Wateruseitwisely.com is a helpful resource for landscape watering guidelines.
Pruning:

- Deadhead annual warm-season flowers such as coreopsis, gaillardia, marigold, and cosmos to extend bloom.
- Light pruning of dead branches from trees and shrubs is okay. Delay heavy pruning until later in the fall.
- Minor citrus pruning is okay; delay heavy pruning until later in the fall.
- Do not prune newly-planted trees or shrubs.
- Cut back (slightly) spring-flowering perennials.
- Pinch back summer-flowering perennials to encourage blooms.
- Prune suckers of tomato plants, and pinch back basil often to keep it from flowering.
Fertilizing:

- Fertilize citrus this month. Water well before and after applying fertilizer. Do not fertilize other fruit trees this month.
- Plants in containers should be fertilized every 2-3 weeks with a water-soluble fertilizer or about once a month with a slow-release fertilizer.
- Fertilize summer herbs such as oregano, basil, and mint with an organic fertilizer.
Yard to do and clean-up:

- Clean up fallen fruit from deciduous trees and citrus trees to discourage pests and disease.
- Provide support for grapevines. Check the underside of grape leaves for skeletonizer eggs; if found, remove and destroy eggs. If you see caterpillars, use Bt to control them before they overtake grapevines.
- Continue to thin fruit on deciduous fruit trees. This article helps explain the process.
- Prune suckers (shoots growing straight up below the bud union) on citrus and other fruit trees.
- Remove spent winter-growing annuals.

- Save seeds from wildflowers like poppies.

- Thin warm-season annuals to keep plants from overcrowding each other.
- Clean up and remove dead or damaged wood and crossing branches on citrus. Delay major pruning on citrus until later in the fall.
- Apply a 3-6 inch layer of mulch around the base of shrubs, trees, annuals, and vegetables.

- Mulching reduces soil temperatures and adds organic matter to the soil.
- Provide shade for annual vegetables with shade cloth or plant in areas that receive afternoon shade.

- Harvest garlic when the lower 3-4 leaves brown. Dig up a test bulb to check on size. Once pulled, let the garlic lie in bed for a day to dry out. Store in a dry shady spot to dry for two weeks. Store in a cool, dry location. Use some and save the largest bulbs to plant in the fall.
- Harvest I’itoi onions this month. Store in a dry, shady spot for a week or two. Store in a dry, cool location. Use some and save some to plant in the fall.
What to plant in your low desert Arizona garden in May

Before planting:
- Prepare beds for planting – Add compost and other organic matter to the soil.
- It’s important to have your soil tested at least once a year. A soil test can determine the health of your soil. I use this test kit from Amazon.
- Add a balanced fertilizer if needed.
Vegetables, herbs & fruit to plant in the low desert in May

(Click the link to read “How to Grow” articles on my website.)
- Armenian Cucumber (ST)
- Basil (ST)
- Bean (Yardlong) (S)
- Black-eyed-peas (S)
- Cantaloupe (ST)
- Jerusalem Artichoke (tuber)
- Malabar Spinach (ST)
- Okra (ST)
- Roselle Hibiscus (ST)
- Sunflower (S)
- Sweet Potato (slip)
SEED, TRANSPLANT, OR BOTH? S = Seed / T= Transplant

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

In this article, learn more about using cover crops during summer to improve garden soil.
Vegetable, herb & fruit seeds to start indoors in May

(Click the link for seed sources.)

- PLANTING GUIDE: Each month lists vegetables, fruit & herbs to plant outside & seeds to start indoors.
- HARVEST GUIDE: Photos show what may be ready to harvest that month.
- Planting dates are for the low desert of Arizona (zone 9b).
Seed Box Labels with planting dates for vegetables and flowers



Flowers to plant in the low desert in May

(Click the link to read “How to Grow” articles on my website.)
- Angelonia (T)
- Celosia (T)
- Coleus (T)
- Coreopsis (ST)
- Cosmos (S)
- Cosmos (yellow) (S)
- Creeping Zinnia* thru the 15th (ST)
- Dusty Miller (T)
- Four O’Clock (S)
- Gomphrena (T)
- Impatiens (T)
- Lisianthus (T)
- Marigold (ST)
- Portulaca / Moss Rose (ST)
- Purslane (ST)
- Rain Lily (bulb)
- Salvia* thru the 15th (T)
- Sunflower (S)
- Tithonia* thru the 15th (S)
- Vinca (T)
- Zinnia (ST)
SEED, TRANSPLANT, OR BOTH? S = Seed / T= Transplant
Flower seeds to start indoors in the low desert in May

(Click the link for seed sources.)


Flowers to Plant Outside & Seeds to Start Indoors Each Month in the Low Desert of Arizona.
• PLANTING GUIDE: Each month lists annual flowers and bulbs to plant outside & seeds to start indoors.
• BLOOMING GUIDE: Photos show what may be in bloom that month.

Arizona annual flowers planting guide helps you learn when to plant flowers in Arizona and whether to plant seeds or transplants.

Would you like more information about gardening in Arizona? This blog post shares 7 tips for growing a vegetable garden in Arizona.
Was this post about gardening in Arizona during May helpful? Please share it:



Jeanette
Sunday 21st of May 2023
What types of lettuce or salad greens can be grown in summer besides kale and spinach?
Dee
Saturday 7th of May 2022
I am new to gardening and I really appreciate all your helpful information. Thank you.
Mariko
Friday 1st of May 2020
I am so glad I found your website. It is, by far, the most helpful resource for me here in my AZ garden. Thank you!
Angela Judd
Friday 1st of May 2020
I am so glad it's helpful. Thank you so much for letting me know.
Cindy Osborn
Friday 1st of May 2020
Thanks for all your helpful information! It is greatly appreciated. Quick question for you; where can one find straw for mulching? I have used cedar chips, and wood chips, but both break down very slowly. I want to try straw. Happy gardening!
Anna
Sunday 1st of May 2022
@Cindy Osborn, if you have a Tractor Supply near you they have it available.
Angela Judd
Friday 1st of May 2020
Straw is a great option and it cools the soil very well. Unfortunately, I don't have a local source to recommend. Check with local farmers or even online on apps such as offer-up. Best of luck with your garden!