Guide
Authors
Paul Larson
Laurie Vance
Deborah North
Publication Date: January 2025 |
View PDF
Monsoon season begins to wind down, but continuing moisture and cooler temperatures are appreciated by gardeners, landscape trees and plants, and heat-loving vegetables alike. Stay vigilant and continue to provide shade for sun- or heat-sensitive plants where needed. Watering needs can vary widely depending on your local rainfall, so continue supplemental watering. Stay on top of any clean-up necessitated by monsoon storms. Resist heavier pruning of trees until later in the year.
Maintenance
- As the monsoon wanes, consider installing active or passive rainwater harvesting systems. Refer to Landscape Management Practices to Optimize Passive Rainwater Harvesting and Plant Health to learn more.
- 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.
Planting
- 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. Learn more by reading Ten Steps to a Successful Vegetable Garden.
- 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
Fertilizing
- For lemon and lime trees, apply the last third of the annual feedings in August through September. Citrus Fertilization Chart for Arizona has more information. 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 washing-effect of monsoon rains. If plants turn a pale green or have reduced growth, flowering, or fruiting, they probably need to be fertilized. Fertilizing Home Gardens in Arizona has more information.
- Prepare in-ground or raised garden beds for fall planting by adding aged compost and/or composted steer manure.
Watering
- 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.