Fall Garden Preparation Checklist

Aerate the Lawn

Fall is the best time to aerate cool-season grasses (fescue, bluegrass, rye). Aeration pulls 2–3 inch plugs from the soil, allowing air, water, and nutrients to penetrate compacted ground. Rent a core aerator for $60–80/day or hire it out for $50–100.

Skip for: warm-season grasses (Bermuda, Zoysia) — aerate those in late spring.

Overseed Thin or Bare Areas

Overseed immediately after aerating — the holes are perfect seed beds. Fall soil temperatures (50–65°F) are ideal for germination and the cooler weather reduces transplant stress. New grass establishes all winter underground, exploding in spring.

Use seed appropriate for your region. Apply starter fertilizer at seeding. Keep lightly moist for 2–3 weeks until germination.

Apply Fall Fertilizer

Use a "winterizer" fertilizer — high in potassium, low in nitrogen. Potassium strengthens cell walls and improves cold hardiness. Apply 4–6 weeks before expected first frost. This feeds roots through fall and provides reserves for spring green-up.

Avoid high-nitrogen fertilizer in fall — it promotes tender top growth that gets winter-killed.

Keep Mowing Until Growth Stops

Gradually lower mowing height over the last few mows of the season to 2.5–3 inches. Grass that's too long going into winter can mat, harbor disease, and suffer snow mold. Don't scalp it — just slightly shorter than summer height.

Continue until grass stops growing (usually after several hard frosts). For a full year-round schedule, see our complete lawn care guide.

Deal with Leaves

Leaves left on the lawn over winter smother grass and harbor disease. Options:

• Mulch mow: Run mower over leaves — shredded leaves decompose and feed the lawn. Works great with a light leaf layer.
• Compost: Rake to a compost pile. Shredded leaves make excellent compost in 6–12 months.
• Bag and remove: For heavy leaf fall — don't let them smother the grass.

Cut Back Perennials (Selectively)

Not all perennials need to be cut back in fall — some provide winter interest and food for birds:

• Cut back now: Hostas, peonies, iris, daylilies (after frost kills foliage), diseased plants
• Leave until spring: Coneflowers, black-eyed Susans, ornamental grasses, sedums — their seed heads feed birds and look beautiful covered in frost

Cut perennials back to 4–6 inches, not to the ground — the stem stubs mark where they are in spring.

Mulch Garden Beds

Apply 2–3 inches of mulch to all garden beds after the first hard frost (not before — you want the ground to freeze, then insulate). Mulch moderates soil temperature fluctuations that heave plant roots out of the ground.

Focus on newly planted perennials and marginally-hardy plants. Keep mulch 2–3 inches away from plant crowns and tree trunks to prevent rot.

Pull Annual Flowers and Vegetables

After frost kills them, remove all annual flower and vegetable plants. Leaving them in the garden over winter harbors pests and diseases. Compost healthy plant material; bag and trash anything that showed signs of disease.

Dig and Store Tender Bulbs

Dahlias, cannas, gladiolus, and caladiums cannot survive freezing winters in-ground (zones 1–7). After frost kills the foliage:

1. Dig bulbs/tubers carefully
2. Shake off excess soil — don't wash
3. Let dry in a cool, dry place for 1–2 weeks
4. Store in paper bags or cardboard boxes with peat moss at 40–50°F
5. Check monthly for rot; discard any that turn mushy

Plant Spring Bulbs

Fall is the ONLY time to plant spring-blooming bulbs (tulips, daffodils, hyacinths, crocus). They need 12–16 weeks of cold to bloom. Plant 6 weeks before the ground freezes.

Depth guide: plant bulbs at 3× their diameter depth. Pointy end up. Mix bulb fertilizer into the planting hole. Mark locations so you don't accidentally dig them up next spring.

Winterize Your Irrigation System

Water left in irrigation pipes freezes, expands, and cracks pipes and heads — a $500–2,000 repair. Do this before the first hard freeze:

1. Shut off the main irrigation water supply
2. Run each zone until it runs dry
3. Blow out remaining water with an air compressor (or hire an irrigation company — about $50–100)
4. Set the controller to "off" or "rain" mode
5. Insulate the backflow preventer if it's above ground

Drain and Store Hoses

Water left in hoses freezes and cracks them. Disconnect hoses from spigots, drain completely, and store indoors or in a garage. Leaving hoses connected can also freeze and burst outdoor spigots.

Install foam insulation covers on outdoor spigots ($2–3 each at any hardware store) before freezing temps arrive.

Clean and Store Garden Tools

Tools stored dirty rust and degrade. Before putting away for winter:

• Wash soil off all tools with a hose
• Dry completely (crucial to prevent rust)
• Sharpen mower blade, pruners, shovels (a sharp tool is safer and more efficient)
• Rub metal parts with an oily rag to prevent rust
• Drain gas from lawn mower or add fuel stabilizer if storing with gas
• Change mower oil if you haven't done it this year

Water Trees and Shrubs Deeply Before Freeze

Drought stress going into winter is a major cause of winter dieback. Give all trees, shrubs, and evergreens a deep soaking in late fall before the ground freezes. Evergreens especially lose moisture through their needles all winter — a well-hydrated plant survives winter better.

Protect Young Trees from Deer and Rodents

Deer browse young trees and shrubs in winter when food is scarce. Rabbits and mice gnaw bark at the base. Protect with:

• Tree guards or wire mesh around the base of young trees
• Burlap wrap for marginally-hardy shrubs in windy locations
• Anti-desiccant spray (Wilt-Pruf) on broadleaf evergreens to reduce moisture loss

Fall Planting: The Best Kept Secret

Fall is actually the best time to plant trees, shrubs, and perennials — not spring. The soil is still warm, encouraging root growth. The cooler air reduces stress. Plants establish roots all fall and winter, exploding in growth come spring.

Plant at least 6 weeks before expected hard frost to allow root establishment. Water weekly until ground freezes. Mulch well after planting.