Marigolds are the hardest-working annual in the vegetable garden: they flower for months, shrug off heat and poor soil, and their roots are famous for discouraging soil pests, which is why you will find them tucked between the tomatoes in almost every good vegetable plot. They are also simply cheerful flowers, in gold, orange and yellow, that bloom from early summer until the first frost.
There are two main kinds to know: French marigolds, which are compact and bushy with small, dense flowers, and African marigolds, which are taller with big, bold pompom blooms. Both grow the same way, and both are excellent in pots, window boxes and edging, as well as in the vegetable garden. If you only grow one flower for your vegetables, make it a marigold.
Marigolds at a glance
| Growing factor | What marigolds need |
|---|---|
| Sun | full sun |
| Soil pH | 6.0–7.0 |
| Days to germination | 5–10 |
| Days to maturity | 45–60 |
| Spacing | 8–12 inches apart |
| Water needs | moderate |
| Cold tolerance | tender |
| Family | Asteraceae |
Starting seeds
Marigolds give you a choice: start seeds indoors for earlier flowers, or sow direct once the soil warms. For the earliest display, sow indoors a few weeks before your last frost — late winter in Zones 3–5, early spring in Zones 6–8, late winter in Zones 9–10 — and transplant out after the frosts end. For direct sowing, wait until the soil is workable and warming: late spring in Zones 3–5, mid-spring in Zones 6–8, early spring in Zones 9–10. Zones 11–13 are frost-free, so both methods work through much of the year; check your local extension service for the best local dates. Seeds germinate in 5–10 days. Keep seed mix or soil evenly moist until seedlings are up, and give indoor seedlings as much light as you can. Our seed starting calculator plans your indoor sowing date, and the germination time calculator estimates when to expect seedlings.
Transplanting and planting out
Transplant seedlings out after the last frost, on a cloudy day or in the evening so they do not wilt in the sun. Space plants 8–12 inches apart — that spacing is what keeps air moving and disease down — and water each plant in well. Our plant spacing calculator works out exactly how many plants fit your bed, and the square foot garden planner helps lay them out.
Soil and feeding
Marigolds grow best in fertile, well-drained soil with a pH of 6.0–7.0. Dig in compost before planting — it feeds the soil and helps it hold moisture without getting soggy — and mulch after planting to keep the roots cool and the weeds down. Feed during the growing season with a balanced fertiliser at the label rate, roughly once a month while plants are actively growing, and stop feeding as the season ends. Our fertiliser calculator works out the right amount for your bed, and the compost ratio calculator helps you make good compost to dig in.
Watering
Marigolds have moderate water needs: keep the soil evenly moist while plants are establishing and flowering, and water deeply rather than little and often so the roots grow down. Water at the base in the morning so the foliage dries during the day, mulch to hold moisture in, and watch for wilting in hot, dry spells. Our watering calculator gives a starting point for your bed size, and the watering schedule generator can build a routine around it.
Sunlight and temperature
Marigolds need full sun — at least six hours of direct sun a day. Marigolds are tender — frost kills them or damages them badly, so they are grown as warm-season plants in most zones and planted out only once frosts are over. In frost-free Zones 11–13 they can grow for much of the year. Use the frost date calculator to find your last frost date. Our sunlight calculator can check whether your spot gets enough sun.
Pests and diseases
The pests and diseases to watch for on marigolds are aphids, whiteflies, slugs. Marigolds are rarely troubled by pests, which is part of their value — they are planted to protect other crops. Slugs may nibble young seedlings, and whiteflies can appear on plants grown under cover. Check plants weekly, looking under leaves as well as on top, and act early. Hand-pick larger pests, knock aphids off with a strong spray of water, and remove badly affected leaves. Keep the area weed-free and avoid wetting the foliage when you water, since damp leaves invite fungal disease. Our pest identifier helper can help identify what you are seeing, and the plant disease checker helps narrow down leaf and stem problems.
Companion plants
Good companions for marigolds are tomatoes, peppers, cucumbers, squash, beans. This is the companion plant other crops want: tomatoes, peppers, cucumbers, squash and beans all benefit from marigolds planted nearby, and marigolds also protect each other when grown in drifts. Our companion planting finder can suggest more pairings for your bed plan.
Harvesting
Marigolds are grown for flowers, not fruit, so harvesting means deadheading. Snip off spent flowers regularly and the plant will keep producing new blooms for months — a marigold left to set seed stops flowering. Pick flowers for drying or for use as a natural dye when they are fully open and dry, in the morning after the dew has lifted. At the end of the season, pull the plants up and compost them. Our harvest date calculator can estimate your picking date from your sowing date, and the vegetable yield estimator helps you work out how much a bed will produce.
Common problems and fixes
| Problem | Likely cause | Fix |
|---|---|---|
| No flowers, only leaves | too much nitrogen or too much shade | Stop feeding, and move or thin plants into full sun. |
| Seedlings eaten overnight | slugs | Protect young plants and water in the morning so the soil surface dries by night. |
| Grey mould on flowers | wet weather and crowded plants | Space plants properly, deadhead regularly, and avoid wetting the flowers. |
No flowers, only leaves
A marigold fed like a hungry vegetable grows leaves and forgets to flower. Marigolds flower best in ordinary or even poor soil, so stop feeding and make sure they get at least six hours of direct sun. Deadheading also pushes new flowers.
Seedlings eaten overnight
Slugs love young marigold seedlings and can eat a whole row in one night. Protect seedlings with a barrier or by watering in the morning, and transplant out sturdy plants rather than tiny seedlings, which are far more vulnerable.
Grey mould on flowers
In wet summers, spent marigold flowers can go grey and mouldy, especially if plants are crowded. Keep to the spacing in the table, deadhead often so rotting flowers do not sit on the plant, and water at the base.
Frequently asked questions
How long does it take to grow marigolds?
From planting to maturity takes 45–60 days. Seed germination takes 5–10 days, and the total time depends on whether you start from seed, a nursery plant, or a bulb or cutting.
How far apart should I plant marigolds?
Space marigolds 8–12 inches apart. That spacing gives each plant room for air movement, which keeps disease down, and room to reach its full size without crowding its neighbours.
What soil pH do marigolds need?
Marigolds prefer a soil pH of 6.0–7.0. Test your soil before amending it — most garden soils are close enough, and guessing with lime or sulphur can do more harm than good.
Do marigolds really keep pests away?
They help, especially against some soil pests, and they attract beneficial insects that eat aphids. They are not a magic shield, though — think of them as one part of a healthy garden, not a replacement for checking your plants.
Are marigolds annuals or perennials?
In most gardens they are grown as annuals: they flower all summer and are killed by the first frost. In frost-free Zones 11–13 they can live longer, but most gardeners still treat them as annuals and sow fresh each year.