First frost is still weeks away (typically mid-October here), but the work you do now determines what you will have in November and next spring.

September in Louisville means warm days, cooler nights, and soil that is still workable. Use the month well.

Harvest and preserve. Cut basil, lemon verbena, and other tender annuals before a surprise cold night. Dry, freeze, or make pesto. Perennials such as sage, thyme, oregano, and rosemary can be harvested more heavily now.

Take cuttings and pot up. Root rosemary, scented geraniums, and lemon verbena. Move tender plants into pots and begin acclimating them to indoor light if you plan to overwinter them inside. Inspect for pests before they come through the door.

Sow cool-season herbs. Cilantro, parsley, chervil, and dill can still be direct-sown. Provide afternoon shade if heat lingers and be ready with a lightweight cover for an early dip into the 30s.

Divide and transplant. Chives, oregano, mint, and lemon balm that have formed tight clumps can be split now while roots can still settle before winter. Replant into amended soil; our clay benefits from compost.

Plant garlic. Late September into October is the traditional window. Choose a sunny, well-drained spot. Mulch after the ground cools.

Ease off water and watch disease. Shorter days mean less frequent watering. Thin crowded stems to reduce powdery mildew after humid spells.

Clean and store tools; note next year’s gaps. Write down which varieties thrived and which struggled in this year’s heat and humidity. Order or save seed while the memory is fresh.

Protect what you want to keep. A simple low tunnel or row cover bought now will be useful when the first frost warning appears in mid-October.

These are ordinary tasks, but they are the ones that keep an herb garden alive from one season to the next.