August feels like the end of the gardening season, but for cool-season crops it’s actually the beginning. As your summer vegetables wind down, August is the window to get fall and winter crops established — and if you time it right, you’ll be harvesting fresh greens well into November, even December in mild climates.
The key is knowing your first fall frost date and working backward from it. Here’s what to plant in August by zone.
August Planting by Zone
Zones 3–4 (First Frost: Mid-September to Early October)
Your window in August is narrow. Focus on the fastest-maturing crops only:
- Radishes (25–30 days): Direct sow for a quick fall harvest before frost
- Spinach (40–45 days): Sow immediately — a fall harvest is possible with fast-maturing varieties
- Lettuce (45–55 days): Sow early August, harvest in late September
- Arugula (35–40 days): Fast and frost-hardy; sow through mid-August
- Turnips (40–55 days): Direct sow for a fall root harvest
Cover beds with row cover (floating frost blanket) to extend the season 2–4 weeks past your first frost date.
Zones 5–6 (First Frost: Mid-October to Early November)
You have the most productive August window. Get these in the ground now:
- Kale (55–65 days): Direct sow or transplant now for fall and early winter harvest — frost improves the flavor
- Spinach (40–50 days): Direct sow; succession plant every 2 weeks through August
- Lettuce (45–60 days): Direct sow or transplant — fall lettuce is often sweeter than spring
- Broccoli transplants (50–60 days from transplant): Set out started transplants now for a fall crop
- Beets (50–65 days): Direct sow for fall roots; baby greens are harvestable in 30–35 days
- Carrots (65–75 days): Sow early August; carrots improve in flavor after light frost
- Chard (50–60 days): Direct sow; tolerates light frost
- Arugula and mustard greens (30–40 days): Fast fall harvest
- Radishes (25–30 days): Multiple successions through August
Zones 7–8 (First Frost: Mid-November to Late November)
A longer fall window gives you more options. August is perfect for:
- All of the Zone 5–6 crops above
- Cabbage transplants: Set out now for a late fall harvest
- Brussels sprouts: Transplant in early August for a November harvest (they need the long season)
- Garlic: Can go in from late September through November — start planning your order now
- Peas: Direct sow in late August for a fall harvest before first frost
- Cilantro: Thrives in cool fall weather; bolts in summer
Zones 9–10 (First Frost: December or No Frost)
August is the start of your planting season — the equivalent of spring for gardeners in cooler climates. Everything that grows in spring in Zone 5 can grow in fall/winter in Zones 9–10:
- Tomatoes, peppers, eggplant (transplant by mid-August for a fall crop)
- All cool-season crops: kale, spinach, lettuce, broccoli, cabbage, chard, beets, carrots, turnips
- Herbs: basil (before it gets too cool), cilantro, dill, parsley
- Beans: can go in through September in Zone 10
August Garden Tasks (All Zones)
Keep harvesting summer crops. Don’t let zucchini, cucumbers, or beans overmature on the plant — ripe fruit left on signals the plant to stop producing. Pick every 2–3 days.
Prep beds as summer crops finish. Pull spent plants, add 2 inches of compost, and get beds ready for fall plantings. Waiting to do this until you need to plant costs you 1–2 weeks of fall growing time.
Water fall seedlings carefully. Soil temperatures are often above 85°F in August, which inhibits germination for cool-season crops. Keep the seedbed consistently moist — even twice daily watering may be needed. Shading the seedbed with a board or shade cloth until germination helps significantly.
Order garlic. Good garlic seed stocks sell out in August and September. Order now for fall planting, even if you won’t plant until October.
