August is two gardens in one: the summer harvest continues while the savvy gardener is already planting and planning for fall.
August is the pivot point of the gardening year. Summer crops are at peak production, but the clock is ticking — days shorten noticeably, and fall is only weeks away. Smart gardeners are doing double duty: harvesting tomatoes and peppers while transplanting fall broccoli, kale, and cabbage starts into beds vacated by spent cool-season crops. August is the traditional month for dividing bearded irises, which bloom best when divided every 3–4 years right after flowering. Seed saving begins in earnest for heirloom varieties. Perennial orders for fall planting should be placed now, as nurseries offer the widest selection before the autumn rush.
Transplant fall brassica starts (broccoli, kale, cabbage, cauliflower) into beds with afternoon shade or shade cloth
Direct-sow turnips, radishes, spinach, and arugula for quick fall harvests
Divide bearded irises — dig clumps, separate rhizomes, trim leaves to 6-inch fans, and replant at soil level
Collect seeds from heirloom tomatoes, peppers, and open-pollinated flowers for next year
Photograph your garden at peak production to reference during winter planning — these images reveal what worked and what was overcrowded
Plant ornamental kale and cabbage now for dramatic fall and early winter texture in borders
Identify perennials that have outgrown their space and flag them for division or relocation in September
Часто задаваемые вопросы
01 What should I plant in August for fall?
Transplant broccoli, kale, cabbage, and cauliflower starts. Direct-sow spinach, arugula, turnips, radishes, and lettuce. In zones 7+, you can still sow snap peas and bush beans for a late harvest. Plant ornamental kale for fall color.
02 How do I divide bearded irises in August?
Dig the entire clump, shake off soil, and separate rhizomes by breaking or cutting them apart. Each division should have a fan of leaves and healthy roots. Trim leaves to 6-inch fans, let cut surfaces dry for a few hours, then replant with the rhizome top exposed at soil level.
03 Should I stop fertilizing in August?
Stop fertilizing perennials and woody plants by mid-August so new growth has time to harden off before frost. Continue feeding heavy-producing vegetables (tomatoes, peppers) through harvest. Fall-planted crops benefit from a starter fertilizer at transplanting.