September can bring occasional hot summer days to southern California but the generally mild days and nights are the ideal growing conditions for a fall garden.
Start Vegetables From Seeds: Just about as many vegetables can be planted in fall as can be planted in spring. These include beans, broccoli, carrots, cauliflower, chard, kale, lettuces, peas, potatoes and radishes.
Freshen Up Your Flower Garden: Most summer annuals are beginning to look ragged by now. If your garden has bare spots, fill them in with cool-season flowers. Remove dead plants, loosen the soil and add garden planting mix. Plants that do well in fall are pansies, calendula, chrysanthemums, foxgloves, snapdragons and asters. Once planted, add mulch about an inch away from plant stems. Mulch will protect plants from damage caused by frost later in the year.
Keep Roses Blooming: Roses can bloom through fall in southern California. Prepare for new growth in September by removing dead flowers and seed pods. Do some light trimming to shape the bush. Expect new blooms in October or early November.
Prune Hedges and Shrubs: Hedges and shrubs have been growing rapidly all summer. By now, they may have lost their shape. Reshape by cutting back straggly stems and trimming sides and tops. This will encourage new growth before winter. Don’t remove growth in the interior of the shrub. A compacted plant protects itself from frost.
Add Bulbs For Spring Color Surprises: Add bulbs to your garden and see what pops up in spring. Plant bulbs that do best in warm weather including calla lily, Dutch iris, freesia and nerine. These perennial bulbs will keep coming back year after year with little care. Unlike other types of bulbs that must be dug up and refrigerated, these bulbs can be left in the ground.
Keep Potted Plants Moist: Outdoor potted plants need more water than plants in the ground. They may need to be watered daily, especially if Santa Ana winds start up in September. These strong winds can dry out a potted plant in a matter of hours. Add fresh mulch to the pot to help hold in moisture.
Prune Fig Trees Once All Fruit Is Harvested: Fig trees produce an abundant amount of fruit. If you wish to trim these fast-growing trees, wait until all the fruit is harvested (usually by early fall). Figs develop on new limb growth so if you wait too long to prune, figs will not be able to grow.