Pima County Gardening Seasonal Reminder - August

• As the monsoon wanes, consider installing active or passive rainwater harvesting systems.
• It may be too hot for tomatoes to set fruit in August, so consider pruning tomatoes by two-thirds for a
  second, fall harvest. Discard or compost the cuttings.
• Unless monsoon-damaged, avoid heavy pruning of most varieties of trees and shrubs. Removing too
  much leafy growth opens the center of the plant to direct sunlight which can scorch lower leaves,
  branches, and trunk not used to that exposure. Remember that loss of shade can adversely affect
  the plants (formerly) underneath. Routine or heavy tree pruning jobs are done later in the year.
• Native trees, such as mesquite and palo verde, however, can be pruned now because they heal
  better during the heat of the summer.
• Dethatch lawns early this month to allow time for the grass to recover before fall. Thatch is an
  accumulation of dead grass plants and roots that covers the soil and forms a dense mat that restricts
  the movement of water and fertilizer. Take a vertical plug out of the lawn and soil to check the depth
  of the spongy thatch layer. If this layer over the soil is one-half inch or thicker, it should be removed
  with a steel tine lawn rake or power dethatcher.
• Keep checking plants for signs of water stress and sunburn.

• Plant bush beans, cowpeas, corn, snap peas, radish, kale, beets, and turnips from seed.
• Start broccoli, cabbage, cauliflower, and brussels sprouts in trays to transplant to the ground or
  raised beds in October.
• Research which trees would best fit your garden for planting next month. Be sure you know the
  expected mature size.
• Tucson Electric Power customers can reach out for information and eligibility on discounted shade
  trees.
• Cacti and agave can continue to be planted or transplanted this month.
• Now is a good time to plant native and near-native perennials.
• Research which cool-season vegetables and flowers you might want to grow - even if not planting
  now.

• For lemon and lime trees, apply the last third of the annual feedings in August-September. Be sure any soil or mulch has not washed in from
  watering or monsoon. It should not sit too close to the trunk.
• For those with roses, you have two choices:
  • Option 1: Give your roses a break during July and August with no fertilizer applications. Start
    back with full-strength slow-release fertilizer in September.
  • Option 2: Continue using slow-release fertilizer at half-strength throughout the summer,
    then change back to full-strength applications as above.
• Continue fertilizing flowers, vegetables, and lawns that may be nutrient-depleted from the washingeffect of monsoon rains. If plants turn a pale green or have reduced growth, flowering, or fruiting, they probably need to be fertilized.
• Prepare in-ground or raised garden beds for fall planting by adding aged compost and/or composted
  steer manure.

• Adjust irrigation for all your plants based on the intensity of your local monsoon.
• If your citrus fruit or pomegranates are splitting, they may be getting too much water. Adjust your
  watering frequency, but not the duration.
• Trees and large cacti may need a deep soaking if your local monsoon is sparse.
• Succulents should be carefully monitored for appropriate watering.

Ten Steps to a Successful Vegetable Garden

Citrus Fertilization chart for Arizona

Harvesting rainwater

Irrigating Citrus Trees

Citrus Fertilization chart for Arizona

Rose Selection and Planting in the Low Desert

Fertilizing Home Gardens in Arizona

Mesquite and Paloverde trees for the Urban Landscape

Pruning Deciduous Shade Trees

Efficient landscape watering

Landscape management practices for passive water harvesting

Landscape Practices for Extreme Heat and Drought

For more information on any of these topics, search our database of Extension publications going back more than 100 years housed in the University of Arizona Campus Repository.