June/July 2021 Garden Checklist
What to Plant: Low Elevations
Transplant sweet potatoes into an area where the vines will have room to spread. Plan on 4 feet by 4 feet square per plant. You can harvest and eat the leaves throughout the summer and then harvest the tubers when they reach maturity in the fall.
Corn, beans and squash are known collectively as the Three Sisters. When planted together, each provides a benefit to the other two. The beans add nitrogen to the soil, which the corn and squash love. The corn functions as a trellis the beans can climb on. The squash shades and cools the soil, reducing stress for the corn and beans. Look for interesting varieties of corn, beans and squash that do well in the low desert at nativeseeds.org.
With its warm nights, July is the optimal month for planting landscape palms. Two popular fan palms for Central Arizona are the California fan palm (Washingtonia filifera) and the Mexican fan palm (Washingtonia robustal), which is the taller and skinnier of the two. Take extra caution not to damage the center of the crown of leaves, where all new growth originates.
What to Plant: Middle and High Elevations
Transplant tomatoes, eggplants and peppers into containers or planting beds. If using containers, go big! The larger the volume of soil you can offer the roots, the more resilient the plant will be to temperature and moisture fluctuations. Sow seeds of bush beans, melons, cucumbers and squash. Promptly cover new plantings with floating row covers to keep whiteflies and birds away.
TREES AND SHRUBS
Transplant trees and shrubs into planting holes that are at least twice the width of the root ball, but no deeper. This prevents planting too deep—a leading cause of trunk failure 5-7 years after installation. Ask your local nursery professional about well-adapted species that thrive at your elevation and exposure.
What to Plant: High Elevations
LEAFY GREENS AND ROOT VEGETABLES
Diversify your late-summer salad with lettuces, both head and leaf, Swiss chard, arugula, kale, spinach, radish, beets, carrots and Napa cabbage, all of which can be planted from seeds now.
Garden Maintenance: All Elevations
CHECK SOIL MOISTURE
As the monsoons return in July, keep an eye on local weather forecasts. Once the dew point is higher than 55 degrees, soil and plant water loss slows down. July’s higher humidity—and hopefully, rain—means outdoor plants will not need to be watered as often. Use a soil probe to check water status and apply water only if needed.
Garden Maintenance: Low Elevations
Give your garden soil, and yourself, a chance to rest and recover. Let the soil lie fallow during summer’s hottest months to break pest cycles, save water and stay out of the heat. Cover fallow beds with a thick, 4-5 inch layer of mulch to suppress weeds. Or, to really heat up the soil and manage pests hiding within, cover beds with thick (2-3 millimeters), clear plastic, available in the paint department of your local hardware store.
DON’T FREAK OUT
July marks the emergence of palo verde root borer beetles from their underground pupal chambers to find mates. These large, 4-inch beetles may frighten newcomers to the desert, but rest assured, they are completely uninterested in, and unable to harm humans or our pets. Palo verde root borers feed on the roots of older palo verdes and other native desert trees. There have been reports of damage from these beetles ultimately contributing to the death of already declining trees, but observing these big beauties in your landscape does not mean treatment is warranted. Do your best to stay out of their way and chuckle at their clumsiness.
Garden Maintenance: Middle Elevations
Restore youthful good looks to shaggy ornamental grasses and shrubs with rejuvenation pruning. Cut overgrown grasses back to mounds 4-6 inches and shrubs to stems 8-10 inches tall. Although harsh, this process will stimulate a flush of new growth. Follow the cutting with thorough irrigation. Be sure to wet as much of the root ball as you can, extending the area where water is applied to the soil just beyond the edge of the plant canopy.
Garden Maintenance: High Elevations
Once the blooms have died and the leaves shrivel, dig up the rhizomes and share with friends.