A Month-by-Month Container Planting Calendar
Container gardening rewards timing more than effort. A crop sown three weeks late often yields half as much as the same crop sown on time. This calendar assumes a temperate Northern Hemisphere climate (roughly USDA zones 7–9, UK, much of Europe and the northern US); adjust by two to four weeks either way depending on your last frost date.
Find your two anchor dates
Everything else follows from these:
- Last spring frost — typically late March in mild areas, late April to mid May in colder ones.
- First autumn frost — typically late September to early November.
Tender crops (tomato, pepper, cucumber, courgette, basil) go out two weeks after the last frost and finish at the first. Hardy crops (lettuce, spinach, kale, chard, peas, broad beans) can go out four to six weeks before the last frost and continue past the first.
The calendar
| Month | Sow / plant | Harvest | Jobs |
|---|---|---|---|
| January | Order seed; chit early potatoes indoors | Winter herbs, chard, kale | Clean and repair containers, plan the season |
| February | Onions, leeks, early peas under cover; chillies indoors | Kale, chard, overwintered herbs | Start tomato seed indoors from late month |
| March | Tomato, pepper, aubergine indoors; broad beans, peas, lettuce, radish outside under cover | Last of winter greens | Replace old potting mix; set up supports |
| April | Lettuce, rocket, spinach, chard, kale, carrots, beetroot, spring onion directly | Radish, early lettuce | Harden off indoor-raised seedlings |
| May | Plant tomatoes, peppers, cucumber, courgette, basil after frost; sow dwarf beans | Radish, lettuce, rocket, spring onion | Begin weekly feeding; succession-sow salads |
| June | Second sowing of beans, carrots, beetroot; basil and courgette | Lettuce, herbs, peas, early broad beans | Watch watering closely; mulch surfaces |
| July | Late lettuce in shade, chard, kale for autumn, herbs | Tomatoes, beans, courgette, cucumber, herbs | Harvest daily; feed fruiting crops twice weekly |
| August | Winter salads, spring cabbage, oriental greens, autumn radish | Peak tomato, pepper, cucumber, courgette | Sow catch crops as containers free up |
| September | Spinach, winter lettuce, rocket, mizuna, chives | Last tomatoes, peppers, beans | Reduce feeding; bring herbs indoors |
| October | Garlic, overwintering onion sets, broad beans in mild areas | Kale, chard, oriental greens, late salads | Clear spent crops; drain self-watering reservoirs |
| November | Little or nothing outdoors | Kale, chard, winter herbs | Protect containers from frost; store empty pots |
| December | Planning; sow microgreens indoors | Kale, chard, indoor herbs | Review what worked; order seed early |
Adapting to a hot climate
In USDA zones 9–11 and similar, the summer is the problem, not the winter:
- Shift the main growing seasons to spring (Feb–May) and autumn (Sep–Nov).
- In high summer, grow only heat-tolerant crops: Malabar spinach, okra, chard, sweet potato, basil, cherry tomato in afternoon shade.
- Use pale containers, afternoon shade and mulch; expect watering twice daily.
Adapting to a cold climate
In zones 3–6 and similar, the season is short and every week counts:
- Start tomatoes, peppers and aubergines indoors 6–8 weeks before the last frost.
- Choose short-season varieties — look for day counts under 65 days.
- Use dark containers to absorb heat, and group them against a south-facing wall.
- Fleece or cloches extend both ends of the season by two to three weeks.
The most useful habit in the whole calendar: sow a small amount of salad seed every three weeks from spring to early autumn. One extra 4 L pot sown fortnightly produces more food over a season than a single large sowing, and it spreads the harvest instead of giving you three weeks of glut and three weeks of nothing.
Keeping your own records
A calendar is generic; your balcony is not. Note down four dates each year — when you sowed, when you planted out, when you first harvested, and when you cleared. After two seasons you will have a calendar tuned to your exact conditions, which is worth more than any general guide. Microclimates are strong: a fifth-floor south-facing balcony can behave two zones warmer than a garden fifty metres away.
Common questions
What if I miss the ideal sowing date?
Sow anyway. Most crops tolerate two to three weeks of slippage; they simply finish later. The exceptions are crops with long maturation times, where a late start means frost arrives before harvest.
How do I find my local frost dates?
Search for your city plus 'last frost date', or ask at a local garden centre. Note that a raised, sheltered balcony can behave a full zone warmer than the published figure for your area.
Can I start a container garden in midsummer?
Yes, with heat-tolerant choices: chard, dwarf beans, basil, Malabar spinach, cucumber and autumn salads. Avoid lettuce and spinach, which bolt or refuse to germinate in high heat.
What can I grow in December?
Kale, chard, winter lettuce under cover, microgreens and indoor herbs. Outdoors, growth slows dramatically, so treat December as planning and maintenance month rather than production.
Do these dates work in the southern hemisphere?
Shift everything by roughly six months: sow tomatoes in September and October, plant out after the last frost around November, and grow winter salads from March. Frost dates and day length vary by latitude, so use local guidance where available.