Winter gardening is one of my favorite parts of year-round growing here in Sonoma Valley. With the right timing, the right crops, and a bit of protection, you can harvest greens, roots, and winter-hardy brassicas even when nights dip near freezing. Winter gardens grow slowly, but they are steady—and with planning, they carry you from late fall through early spring.

Visit the Winter Garden and Season Extension Learning Hub

Below is a complete guide based on decades of winter growing in raised beds and mounded beds.

Why Winter Gardening Works

Winter vegetables don’t mind cool temperatures—in fact, many improve in flavor with cold. Growth slows once days shorten, but hardy crops hold in the garden like a natural refrigerator. The key is to:

Plant at the right time (usually late summer to early fall)
Choose truly cold-tolerant varieties
Give protection when frost or extended freezes are forecast

Best Vegetables for Winter Growing

1. Leafy Greens

These are among the most dependable winter producers.

Kale

Planting: Start seeds mid-August to mid-September; transplant by early October.
Harvest: November through March; outer leaves first.
Protection: Minimal—row covers during frost or heavy rain.

Spinach

Planting: Direct-seed September through early October.
Harvest: November–February.
Protection: Row cover or low tunnel helps with strong cold snaps and keeps leaves clean.

Swiss Chard

Planting: Transplant late August–September.
Harvest: October–March (slower in deep winter).
Protection: Light frost cloth; chard survives mild freezes.

Winter Lettuce

Planting: Transplant September–October with cold-tolerant varieties (Winter Density, Arctic King).
Harvest: November–January for heads; longer for cut-and-come-again.
Protection: Best grown under a low tunnel or doubled row cover.

2. Root Crops

Roots store beautifully in the ground, making them ideal winter harvests.

Carrots

Planting: Direct-seed August–September.
Harvest: November–February; sweetens in cold soil.
Protection: Mulch with straw to prevent soil from crusting or freezing.

Beets

Planting: Direct-seed August–September.
Harvest: October–January.
Protection: Light mulch or row cover during frost.

Turnips

Planting: Seed early September–early October.
Harvest: November–January.
Protection: Usually none; row cover in freezing nights.

Radishes (Winter Types)

Planting: August–September for daikon, watermelon, and black radishes.
Harvest: October–January.
Protection: Mulch or row cover through freezes.

3. Brassicas

These thrive in cool weather and taste better after a frost.

Broccoli

Planting: Transplant late August–September.
Harvest: November–January.
Protection: Row cover until established; low tunnel during freezes.

Cabbage

Planting: Transplant late August–early September.
Harvest: December–February.
Protection: Minimal; heads withstand cold well.

Cauliflower

Planting: Early fall transplants (August–September).
Harvest: November–January.
Protection: Sensitive to cold—use row cover or a tunnel in freezing spells.

Brussels Sprouts

Planting: Transplant July–August for winter harvest.
Harvest: November–February.
Protection: Minimal; very hardy.

4. Alliums

Slow but steady winter crops.

Garlic

Planting: October–November.
Harvest: Late spring–early summer.
Protection: Mulch heavily with straw; garlic overwinters easily.

Onions (Bulbing & Bunching)

Planting: Transplant or seed sets in October–November.
Harvest: Bulbing onions in spring–summer; scallions all winter.
Protection: Row cover helps in extended cold.

Leeks

Planting: Transplant August–September.
Harvest: December–March.
Protection: Mulch mounds; usually no cover required.

5. Overwintering Crops for Early Spring Harvest

These are planted in fall to mature in March–May.

Fava beans – Plant in October; harvest April–May.
Overwintering broccoli – Sow in September; harvest March.
Spring onions – Plant October; harvest February–April.
Overwintering carrots – Seed early September; harvest March.

How to Protect Winter Vegetables

1. Row Covers

My go-to protection for most crops.

Lightweight fabric (0.5–1.0 oz) protects to about 28°F.
Lets in light, air, and water.
Best for greens, roots, and newly transplanted brassicas.

2. Low Tunnels

For extended cold or wind.

Constructed with hoops and plastic or fabric.
Provide a microclimate 5–10°F warmer.
Essential for winter lettuce, cauliflower, or strong winter storms.

3. Mulch

Straw, leaves, or compost.

Insulates the soil around roots.
Prevents soil from freezing and helps retain moisture.
Particularly useful for carrots, beets, turnips, leeks, and garlic.

4. Cold Frames

For intensive winter growing.

Great for lettuce, spinach, and herbs.
Allows near-continuous harvests even in deep winter.

Best Planting Timing by Month (Typical Mild-Winter Climate)

(Adjust earlier for colder zones)

July–August

Brussels sprouts
Cabbage
Early broccoli
Overwintering varieties

August–September

Kale
Chard
Beets
Carrots
Radishes (winter types)
Broccoli
Cauliflower
Leeks

September–October

Spinach
Lettuce (winter-hardy)
Turnips
Scallions
Fava beans
Overwintering onions

October–November

Garlic
Bulbing onions (short-day types)

Final Thoughts

A winter garden is really a fall-planted garden. Once plants are established before the first frost, they grow slowly through winter but stay vibrant, productive, and flavorful. With simple protection—row covers, tunnels, mulch—you can harvest your own fresh vegetables for months.