August is the month of abundance and the month of planning for autumn at the same time, and the garden tasks in August ask you to do both. The summer harvest is at its peak, the freezer and pantry are filling, and yet the fall garden has to be sown now or there will be nothing to harvest in October. The August skill is succession: pick, preserve, and plant the next crop in the same bed on the same day. This guide splits the work by zone band — cold zones 1–4, temperate zones 5–7, warm zones 8–10, and frost-free zones 11–13. Frost dates are given only as averages and ranges, never as exact dates for a particular place, and zones 11–13 are frost-free, so their calendar runs on heat and rain instead. Before you act on any timing here, check your local extension service for the frost dates and sowing windows that fit your area.
Cold zones 1–4: sow fall crops fast and harvest summer crops daily
In zones 1–4, average last frost dates fall roughly from late May into June, and average first frost dates arrive roughly from mid-September to early October, so August is the last safe month for fall sowing. Seed starting indoors is limited to fall lettuce and spinach for transplanting, and any last brassicas that need a head start.
Direct sowing outdoors is urgent for fall crops: sow lettuce, spinach, kale, radishes, turnips, peas, carrots and beets early in August so they mature before the first frosts, and sow green manures on beds that are finishing. Transplanting is fall brassicas, lettuce and spinach from July sowings, set out in the evening and watered in well, with fleece ready for cold nights later in the month. Pruning is light: pinch out tomato side shoots, remove the tops of tomato plants late in August so fruit ripens instead of new growth forming, deadhead flowers, and cut back spent perennials. Fertilising is tapering: feed tomatoes and squash for the last time early in August, feed containers, and stop feeding roses late in the month so new growth hardens before frost. Pest and disease watch means slugs after rain, cabbage worms on fall brassicas, aphids, and late blight on tomatoes in wet weather — remove affected leaves and keep airflow good. Watering is still a big job: water deeply in the morning, mulch thickly, water containers daily, and keep watering even for tomatoes. Harvesting is at its peak: tomatoes, zucchini, cucumbers, beans, corn, carrots, beets, herbs, berries, apples and plums, and our harvest date calculator can help time the pickings. Soil and compost work means mulching beds, turning the heap, adding compost to beds as summer crops finish, and sowing green manures. Houseplant care is late-summer care: plants outdoors in shade, regular feeding, daily watering for small pots, and start thinking about which plants need to come inside in September.
Temperate zones 5–7: fall garden goes in and summer harvest is preserved
Zones 5–7, with average first frost dates generally from mid-October to early November, make August the fall-sowing month. Seed starting indoors is for fall lettuce, spinach and herbs that will go out under cover, and for overwintering onions in zone 7 late in the month.
Direct sowing outdoors is for fall crops: sow lettuce, spinach, kale, radishes, turnips, carrots, beets, peas and beans early in August, and sow green manures on empty beds. Transplanting is fall brassicas, lettuce, spinach and kale from July sowings, set out in the evening and watered in well. Pruning is tidying: pinch out tomato tops late in August so fruit ripens, deadhead roses and perennials, cut back lavender, and shape hedges for the last time this year. Our pruning calendar covers the timing. Fertilising is tapering for most plants: feed tomatoes and containers for the last time, feed fall crops lightly, and stop feeding roses and shrubs so growth hardens before frost. Pest and disease watch means cabbage worms on fall brassicas, slugs, spider mites in dry weather, powdery mildew and late blight — check weekly and remove affected leaves. Watering remains a major job: water deeply in the morning, mulch thickly, water containers daily, and water fall sowings gently until they establish. Harvesting is abundant and preserving begins: tomatoes, zucchini, cucumbers, beans, corn, peppers, eggplant, carrots, beets, herbs, berries, apples and pears. Freeze, dry, pickle and jam the surplus now, because September brings even more. Soil and compost work means mulching beds, turning the heap, adding compost between crops, and sowing green manures. Houseplants outdoors need regular water and feeding, and August is the month to check them for pests before they come inside in September.
Warm zones 8–10: fall planting begins as heat eases
In zones 8–10, average first frost dates run roughly from mid-November in zone 8 to late December or never in zone 10, so August is the start of the fall garden. Seed starting indoors continues for fall crops: start tomatoes, peppers, eggplant, broccoli, cabbage, cauliflower and lettuce indoors for transplanting in September, when the heat breaks.
Direct sowing outdoors is for fall crops late in August: sow beans, squash, cucumbers, carrots, beets, lettuce and herbs once temperatures ease, and sow green manures on empty beds. Transplanting is fall tomatoes, peppers and brassicas from July sowings, set out late in August in the evening and watered in well, with shade cloth handy for hot afternoons. Pruning is light: deadhead flowers, pinch tomatoes, cut back spent summer growth, and shape shrubs. Fertilising is for fall crops: feed new transplants lightly, feed containers, and refresh beds with compost before fall planting. Pest and disease watch is intense in August heat and humidity: spider mites, whiteflies, aphids, squash vine borers, hornworms and fungal diseases all need weekly checks, and good airflow matters most. Watering is critical: water deeply in the morning, mulch heavily, water containers daily, and water at the base to keep leaves dry. Harvesting continues: tomatoes, peppers, eggplant, okra, squash, melons, beans, corn, herbs and berries, with summer crops slowing as fall crops take over. Soil and compost work means preparing fall beds with compost, mulching heavily, keeping the heap moist and turning. Houseplants outdoors need shade, daily water and a check for spider mites in dry heat.
Frost-free zones 11–13: tropical planting and steady harvests
Zones 11–13 are frost-free, so August has no frost dates to plan around. The work is heat, rain and disease watch. Seed starting is direct for most crops, but keep starting tomatoes, peppers and eggplant in trays, and sow heat-tolerant greens such as amaranth, Malabar spinach and okra.
Direct sowing covers beans, corn, squash, cucumbers, melons, okra, sweet potatoes, carrots, beets, herbs and tropical vegetables. Transplanting is continuous: set out tomatoes, peppers, eggplant, basil, cucumbers and tropical fruit trees, and plant bananas, papaya and pineapples now. Pruning is shaping and tidying: cut back spent growth, shape fruit trees after harvest, and remove dead wood, always giving plants airflow. Fertilising is steady and light: feed vegetables every few weeks, feed citrus and fruit trees, and use compost tea for a gentle boost. Pest and disease watch is weekly and year-round: aphids, whiteflies, spider mites, caterpillars, fungal spots and fruit flies all need attention, and in August humidity makes fungal disease the biggest risk, so space plants well and water at the base. Watering needs care in both directions: water deeply in dry spells, but make sure pots and beds drain freely in heavy rain so roots do not rot. Harvesting is abundant: tomatoes, peppers, cucumbers, beans, leafy greens, herbs, citrus, bananas and papaya. Soil and compost work never stops: keep the heap hot and turning, add green waste, and refresh beds with compost. Houseplants outdoors need dividing, repotting and a check for pests and rot in humid weather.
Preserving, seed saving and the August checklist
August is preserving month: freeze beans and berries, dry herbs, make tomato sauce, pickle cucumbers and jam soft fruit, labelling everything with the date and variety. It is also seed-saving month: save seed from open-pollinated tomatoes, beans, peas and lettuce, drying it thoroughly and storing it in labelled envelopes in a cool, dry place. Do not save seed from hybrid varieties, which will not come true. Check our seed-starting calculator when planning fall sowings, and keep a harvest log for next year.
Frequently asked questions
What should I plant in August?
In zones 1–4, sow fall lettuce, spinach, kale, radishes and peas early in August. In zones 5–7, sow fall carrots, beets, lettuce, spinach and kale, and transplant fall brassicas. In zones 8–10, start fall tomatoes and brassicas indoors and sow fall crops late in the month. In zones 11–13, sow warm-season crops direct. Check your local extension service for the windows that fit your area.
Should I pinch out tomato tops in August?
Yes, in zones 1–7, pinch out the growing tip of tomato plants late in August so the plant puts energy into ripening fruit already set, rather than new growth that will not ripen before frost. In zones 8–13, where the season is longer, you can let plants keep growing, but pinch out side shoots regularly.
What can I harvest in August?
In zones 1–4, tomatoes, zucchini, beans, corn, berries and early apples. In zones 5–7, tomatoes, cucumbers, peppers, eggplant, corn and stone fruit. In zones 8–10, tomatoes, okra, melons, peppers and eggplant. In zones 11–13, tomatoes, peppers, beans and herbs all month.
How do I protect fall seedlings from slugs?
Protect young fall crops with copper tape or collars, go out after dark and hand-pick slugs, keep beds clear of debris, and avoid evening watering. Beer traps help, and a mulch of sharp grit around precious seedlings can deter them.
Can I sow green manures in August?
Yes, August is an ideal month to sow green manures such as crimson clover, winter rye and field beans on beds that have finished cropping. They protect the soil, suppress weeds and add organic matter when dug in, and they give the soil a rest before next spring.