September Gardening Tips

Maintenance & Cleanup

Harvest and store root crops: Dig up potatoes once tops yellow and die down; store in a dark, cool spot. Mulch carrots, beets, and parsnips for winter harvesting.
Gather and process winter squash: Wait for the ground spot to shift from white to cream/gold, then harvest, clean, and cure at room temperature before transferring to cooler storage.
Lawn care: Best time to fertilize and stop irrigating after Labor Day to suppress European crane fly.
Clean garden debris: Pull spent annuals, diseased leaves, and fruits. Compost healthy material.

Divide perennials: Split iris, peonies, hostas, and other heavy clumpers for better fall growth.
Fall planting: Ideal window for cool-season cover crops (annual rye, crimson clover, fava beans), new lawns, trees, shrubs, and perennials—soil still warm promotes strong root systems.
Bulb planting: Plant daffodils, tulips, crocuses now; mix in phosphorus and calcium when planting.
Garlic time!: Plant garlic this month for a summer harvest.

Slug control: Patrol in the evening; use pet-safe baits like SLUGGO and traps now to prevent next year’s population.
Root weevils: Treat rhododendrons and azaleas showing notched leaves with beneficial nematodes.
Disease sprays: Monitor for beetle and cane spot on berries; apply copper sprays on peaches, cherries, and junipers after pruning dead wood.

Mulch beds: Apply 2–3″ of organic mulch to protect roots, suppress weeds, and enrich soil over winter.
Garden cleanup for winter: Weed thoroughly to prevent seeding; rake patios and compost weeds before freezing temps set in.
Tool and system prep: Drain hoses and irrigation systems; clean and oil tools for off-season storage.

Bring houseplants inside: Clean foliage, check for insects, repot if needed before cooler nights arrive.
Overwinter tender perennials: Take cuttings from salvias and other tender summer plants to root and overwinter indoors.