How to grow marigolds from seed

If you're wondering how to grow marigolds from seed, you're in good company. A favorite in gardens around the world, marigolds are full of color and bring a burst of summer cheer to any windowbox, hanging basket, planter or border. Not only popular with gardeners, they are also a favorite of butterflies and bees. 

For best results, it's important to know when to start marigolds from seed indoors. With some solid growth behind them, you can plant marigolds outdoors, where they are easy-to-grow, excellent companion plants. 

'Grow marigolds near vegetables to keep pests away,' advises Sue Sanderson, Horticultural Executive at Thompson & Morgan. They are especially well suited as strawberry companion plants as they are very good at protecting against whitefly.

Read on to find out how to grow marigolds from seed in your own garden. 

How to grow marigolds from seed from a packet

Marigold seeds are one of the easiest flowers to grow from seed. If you're sowing indoors, then you can start growing them anytime between late winter and early spring, while if you're planting them directly, then wait until late spring to early summer before sowing your seeds.

• Fill seed trays or cell packs with seed compost.
• Press the seeds into the compost.
• Lightly cover the seeds with more compost.
• 'If kept at 70-75°F germination usually occurs between 5 and 20 days,' says Don McCulley, owner of Swallowtail Garden Seeds.
• Once your seeds have germinated, let them grow until their second – 'real' – set of leave appear. If you have grown in seed trays then thin them out until they are about 11 inches apart.
• 'Gradually harden off before planting out after the last frosts,' advises Sarah Raven. You can do this by putting the trays outdoors on sunny days, then bringing them inside in the evening.
• When the seedlings have reached a few inches tall then transplant the young marigolds to grow in pots, hanging baskets or into the flower bed.

'Once they get going, marigolds will continue growing easily, even if you forget about them,' says Sue Sanderson, Horticultural Executive at Thompson & Morgan in a recent blog post. 'Be sure to protect your marigolds from frost as they don't like the cold.'

How to grow marigolds from seed from a flower

If you already have a marigold plant in your garden then it couldn't be easier to learn how to grow marigolds from seed.

• When the marigold's petals have done dry and crispy to the touch they are ready to harvest for seeds.
• Deadhead the spent flower and then pull the petals upwards, out of the flower.
• This will reveal the seeds which are black tipped with white tops.
• Put the seeds in a plastic container and put in the fridge to keep them fresh.
• Sow the seeds, as you would those from a packet, the following March for beautiful blooms come May.

If you already have established marigolds in one part of the garden and would like some more, you can simply leave the flowers to self-seed and over the course of a few years, the space will be full of these vibrant blooms. 

How to grow marigolds from seed in the ground

It's actually very easy to grow marigold seeds directly into your border.

• Make sure that the soil is free from weeds, then rake until it its fine and crumbly.
• Once the soil is prepared then create narrow rows (about 12mm deep).
• Then sow the seeds into the row and cover with soil.
• For optimum growth, marigolds prefer loamy soil with a neutral pH.

How do you germinate marigold seeds?

• You germinate marigold seeds by scattering them on the top of the soil and then covering in a very fine layer of compost.
• Keep moist and in warm conditions, whether outside or in.
• If the temperature is warm, germination typically takes between 5 and 7 days though can be as long as 20 depending on the temperature and amount of water.

How long does it take to grow marigolds from seed?

FAQs

It takes around eight weeks to grow marigolds from seed to flowering. Once they have had their first flowers, marigolds will continue to bloom for months throughout summer and into fall so long as you regularly deadhead the spent blooms.