Storm clouds boil up south of Tucson, the first signs of monsoon weather this year, Wednesday, July 2, 2014.

Kelly Presnell / Arizona Daily Star

Monsoon rain has arrived. Time to get that seasonal garden planted.

The arrival of summer rains mark a renewal of plant life in the desert, says gardener Casey Townsend. “That’s when our growing season really starts.” That applies to gardening and agriculture, too.


When Sonoran Desert watercourses flowed more regularly, Hohokam and descendant Tohono O’odham farmers used rain-swelled rivers to irrigate their summer fields of corn, beans and squash.

Grouping these crops is known as three sisters planting. They help each other grow. Climbing bean plants wrap around corn stalks and both shade squash plants.

Tohono Chul Park replicates this traditional planting in its Sin Agua (“without water” in Spanish) Garden.

The northwest-side botanical garden has a channel that guides rainwater runoff from a nearby parking lot to a bed surrounded by berms. That runoff floods the garden.

After the first intense rain — a rainfall rate equal to about a half-inch an hour — park workers till the moistened soil. Following the second storm and after the collected water seeps into the soil, seeds of local corn, O’odham squash and tepary beans are dropped into holes created by a pole. From there, the garden is at the mercy of the weather.

“If we don’t get rain, we don’t get crops,” says Lee Mason, the park’s director of general services.

Tohono O’odham built their farms next to rivers and creeks, diverting the rainwater into their fields. Modern gardeners can do something similar by diverting rainwater from roofs, driveways and other hardscapes. Be careful, though, about how much water you put into the bed.

“When seedlings first pop out of the ground, you don’t want to flood it again,” Mason cautions. “You don’t want to drown them.” Wait until they’re mature, he adds.


Townsend, founder of the Tucson Aquaponics Project, has used modern conveniences for monsoon gardens he’s grown for 10 years. Drip irrigation and hand-watering supplements rainwater to ensure a good crop every year.

He prefers to plant before the summer rainy season, which he says also follows tradition. “The definition of monsoon gardening was when the cicada started to buzz,” Townsend says. “You start planting and then hope and pray for rain.”

Ideally, seeds of 90-day or other fast-growing corn should be sown in mid-June. Mid-July is about the latest to plant corn starters, he suggests. Put in any type of melon, squash and pole bean seed close to the corn.

By September the corn is ready for harvest, he says; melons and squash are ready later in the fall.

While many gardeners abandon plots in the heat of the summer, Townsend says it’s the best time to be in the yard.

“I love the rain and the smell, and the soil’s damp,” he says. “It’s wonderful to be out there.”

Contact Tucson freelance writer Elena Acoba at

Contact Tucson freelance writer Elena Acoba at