Marigold
French Marigold, African Marigold, Pot Marigold, Tagetes
One of the best companion plants in the garden — French marigolds (Tagetes patula) excrete thiophene compounds from roots that deter nematodes; plant thickly for 3+ months for best effect. Strong scent deters many insects. Plant near tomatoes, peppers, cucumbers, and squash. Deadhead spent flowers to prolong blooming. Very easy from seed — direct sow after last frost or start indoors 6–8 weeks early.
- Germination
- 5–7 days
- Soil temperature
- 21–24 °C
- Harvest after planting
- 45–65 days
- Spacing
- 25–30 cm
When to plant marigold
Start seeds indoors 6–8 weeks before your last spring frost, and plant out within 2 weeks after it.
Dashed line: typical last spring frost in zone 7 (Apr 5). Zone dates are averages; most of the UK is zone 8–9, central Europe 6–7 and the Baltics and Scandinavia 4–6. In the app, Tomatograph uses your garden's own frost dates.
How to grow marigold
- 1
Sow
Sow indoors 6–8 weeks before the last frost, or outdoors after the last frost. Seedlings appear in 5–7 days.
- 2
Plant out
Plant in full sun after the last frost. Marigolds transplant easily and flower within 6–8 weeks.
- 3
Use as a companion
Plant thickly near tomatoes, peppers and squash. French marigold roots release compounds that deter soil nematodes.
- 4
Deadhead
Remove spent flowers to keep plants blooming until frost.
Growing conditions
Light
Full sun
Water
Low water
Temperature
10–35 °C
Frost tolerance
Frost-sensitive — protect below 0 °C
Days to maturity
45–60 days
How Tomatograph watches your marigold
Tomatograph checks your local forecast every morning and only speaks up when one of these applies to your garden.
- Forecast of 2 °C or lowerFrost alert the evening before: cover plants with fleece or bring pots inside.
- 3 days at 35 °C or aboveHeat-wave alert while plants are flowering or fruiting: shade and water early.
- Humidity above 80% for 48 hoursCheck for powdery mildew, which thrives in those conditions.
- Within a week of maturityHarvest-window reminder based on when you planted.
Marigold questions
- When should I plant marigold?
- Start seeds indoors 6–8 weeks before your last spring frost, and plant out within 2 weeks after it.
- How long do marigold seeds take to germinate?
- Usually 5–7 days at a soil temperature of 21–24 °C.
- How long until I can harvest marigold?
- About 45–65 days after planting out, depending on variety and weather.
- How far apart should I plant marigold?
- Allow 25–30 cm between plants.
- What grows well with marigold?
- Good neighbours include tomato, pepper, cucumber, squash.
Growing guide written by Tomatograph. Planting figures from openplantdb (CC0 1.0). Zone frost dates are averages from openplantdb (CC0 1.0).