Even in regions with warm winters, there are September gardening tasks to get you ready for the next full growing season. The Southwest region comprises Utah, Arizona, New Mexico, and Colorado, although some extend the designation to include Nevada. Either way, these areas are hot and dry, but cool down a bit in fall and winter. A regional to-do list can get gardeners in this range ready to complete fall chores.
Southwest Gardening in September
September in the Southwest is a beautiful time of year. Temperatures during the day are no longer in the triple digits and the evenings are delightful and cooler. Most gardens are still in full swing, and it is a good time to plant cole crops such as broccoli, cabbage, and kale.
Harvesting on many vegetables is in full swing and crops like persimmons and citrus are beginning to ripen. It is also time to do some maintenance so plants will not suffer in the freezing temperatures that are coming.
Since cold temps are around the corner, it is a good time to mulch around sensitive plants. The mulch will protect roots from freezing conditions. Keep mulch a few inches (8 cm.) away from stems to avoid mildew and rot issues.
You may also prune summer blooming shrubs that are cold hardy, but don't prune tender plants yet. Light pruning of trees is also allowed but avoid hard pruning until February. Roses should be lightly pruned and fertilized.
Due to the milder temperatures, it is also a good time to install many plants. There are many chores to do with your perennials as well. Cut them back by one third and divide any that have died out in the center.
Regional To-Do List
- Plant cool season crops
- Harvest onions and garlic once tops have died back. Dry for three weeks and store in a cool, dry location.
- Harvest potatoes once the greens are dead.
- Harvest pears as soon as they easily twist off the tree.
- Aerate sod as needed and apply an early month slow-release food.
- Fertilize citrus trees.
- Fertilize herbs and vegetables.
- Remove spent blooming annuals and save seeds for next year.
- Cut back and divide perennials.
- Lightly prune most winter tolerant trees and shrubs but not fruit trees.
- Pull root vegetables such as carrots.
- Divide ornamental grasses and spring and early summer blooming perennials.
- Cover tomatoes and other tender plants with frost blankets at night.
- Start moving indoor plants that were out to enjoy the summer.
Tips on Southwest Gardening
September in the Southwest is a great time to think about the future. You can start amending soil with compost or manure, which will break down over the winter and leave your soil juicy and rich.
You should check your turf, shrubs, and trees for insect damage. Before leaf drop, use recommended sprays to control insects such as raspberry crown borer, boxelder bugs, and rust mites.
It is also important to keep up watering but adjust the schedule as the weather cools. Reset the irrigation system to reflect the cooler, shorter days.
Since the weather is milder, September gardening tasks are less of a chore and more of a delight.