How to grow French Marigold

Sowing to flowering approx 8-10 weeks. Can cope with wind and strong rain, but prefer a sunny summer

Sow the seed thinly in pots or trays on a windowsill or in a greenhouse in a good quality, finely sieved, moist compost. Remove seed tray cover at first sign of seed germination.
Germination is quick and easy, and the seeds of a size that than be handled individually. It is possible, therefore, to plant the seeds in the first instance as a single seed in a very small starter pod, and pot up at the sow of the first true leaves.
The seeds themselves are not expensive but this conservative measure allows a packet to last for a few years and provide swaps.

Sow at a depth of approx. 0.23 inches (0.6 cm) and aim for a distance of at least 1.95 inches (5.0 cm) between French marigold plants. Soil temperature should be kept higher than 15°C / 59°F to ensure good germination.

By our calculations*, you should look at sowing French marigold about 49 days before your last frost date .

Transplant seedlings spacing them 5cm apart in trays and grow on, at the emergence of the first true leaves. Handle the seedlings by the seed leaves as you transplant into 5cm cells or small pots. Acclimatise the plants to outside conditions and then plant 15 – 23cm apart in a sunny place, after the danger of frost has passed. Can cope with any soil.

As French marigold is half hardy, ensure temperatures are mild enough to plant out (around 12°C / 54°F as a guideline) - wait until after your last frost date to be on the safe side.

Normally it is good practice to dead head old flowers to encourage more for the duration of the summer, but seeds are set easily and one or two heads can be left to collect seeds.

Allow the seed head to dry on the plant and collect on a dry day. Dry further indoors, clean and store.

These estimates for how long French marigold takes to sprout, grow and harvest are from real observations from real gardeners, right around the world.

Our when to plant French marigold estimates are relative to your last frost date.

Marigolds typically have 13 petals. ¹

Marigold, French marigold

Tagetes signata

¹ “Nature by numbers” Eureka may 2011 The Times (offline version)