Sunny days still bring the heat, but cooler nights hint of things to come. It’s time to dig out your gardening tools!
Plant citrus while the weather is still warm. Choose varieties that are better adapted to desert conditions.
Plant strawberry varieties that perform in low-desert conditions. Choose a location that has protection from afternoon sun.
Plant fall herbs such as chives, thyme, catmint, cilantro, cumin, dill, fennel and parsley.
Transplant herbs such as lemongrass, marjoram, mint, oregano, rosemary, sage and thyme.
Dig compost into vegetable beds. Rearrange container plants to sunnier locations as the sun’s arc slips southward.
Chill tulip, crocus, daffodil and hyacinth bulbs in the refrigerator for eight weeks prior to planting.
Cut back tomatoes and peppers that made it through the summer to promote a new bloom before frost.
Trim roses and remove dead twigs to promote a second bloom in the fall.
Prune shrubs such as oleander, privet, xylosma, Texas ranger and Arizona rosewood that have become overgrown.
Cut back on water for deciduous fruit trees, grape vines and citrus to slow growth and get ready for cooler temperatures.
Water citrus deeply out to the plant’s canopy every two weeks.
Hose off dusty plants to control spider mites.
Divide iris this month. Dig up large clumps and cut rhizomes into small pieces.
Pull and compost the last of the summer annuals.
Refresh garden beds by incorporating four to six inches of organic matter. FERTILIZE
Fertilize with nitrogen in early September to provide nutrients to summer-stressed plants. Water the day before and after applications to prevent burn.
Feed roses with a slow-release fertilizer that will last through fall. Fertilize citrus with the third and final application of nitrogen for the year.
Add organic nitrogen sources to the soil, including alfalfa meal, blood meal, coffee grounds, cottonseed meal, fish emulsion and guano.
Chile peppers are available in many colors, shapes, sizes and degrees of heat. The key factor affecting how fruit set is night temperature, which ideally should be between 65 and 80 degree. Bell pepper varieties do not set fruit when temperatures are over 90 degrees, but may begin to do so once the weather is cooler. If bell-type peppers are desired, consider the smaller pod “Carmen Sweet Pepper.”
Chiles need six hours or more of sunlight. Provide full sun in the morning and 50 percent afternoon shade. In the fall, fewer blossoms will appear as the weather turns cooler.
Monsoon rains help quench the thirst of summer plants.
Set out heat-tolerant seasonal color blooms such as cosmos, gaillardia, gazania, globe amaranth, lisianthus, periwinkle and zinnia.
Put in warm-season vegetables such as Armenian cucumbers, black-eyes peas, corn, tepary beans, gourds, melon, okra and summer squash.
Harvest basil often and prune at least 1/3 of the growth to ensure an early fall harvest. Use steel tongs to remove the juicy fruit from the prickly pear cacti.
Feed blooming plants often during the wet season with high-phosphorous fertilizer. Fertilize palms during this rainy season.
Frequent irrigation leaches nutrients, so feed with a slow-release fertilizer.
Prune mesquite and palo verde trees during summer. These trees heal more quickly during hot weather.
y early in the morning, when it’s not raining. Soak the entire root area of trees and shrubs weekly. Adjust your irrigation as needed through the monsoon season.
Summer annuals in pots may dry out quickly, so check irrigation systems often.
Protect container plantings from intense reflected heat and sun. Non-native cacti and succulents prefer some shade. Use 50-75 percent shade cloth over peppers and tomatoes.
Heat-loving tecoma shrubs such as red bird of paradise, fairy duster, Texas ranger, palms, portulaca and perennial sunflowers can be planted now.
Make use of the summer rains by harvesting the water. That may include building a collection system or simply using the runoff and carrying it to specific planting spaces.
Watch for insect infestation on plants. Heat- and drought-stressed plants are especially vulnerable to disease.
Watch for cochineal scale on prickly pear cacti and wash off any that appears.
Avoid standing water that might harbor mosquitoes.
TIP OF THE MONTH
Summer vegetables can become stressed from the heat this month, with wilted leaves in the morning an obvious signal. Late-afternoon wilting also may be heat stress, but as evening approaches the plants may perk up again.
To keep soil moist, water slowly and deeply. Add fertilizer to moist soil only, then add more water to move it to the roots.
Eggplant, corn, squash, beans, melons, black-eyed peas, cucumbers, peppers and okra are some of the best warm-season crops. As melons ripen, place a board beneath them to prevent insect damage.
Corn, squash and beans are known as “the three sisters,” and usually are planted together. The corn plants provide shade, the beans add nitrogen to the soil, and the squash foliage shades the ground, preventing evaporation of the monsoon rains.
As the weather warms, we Tucsonans get busy in our gardens.