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Flower Seeds to Sow in March

Flower seeds to sow in March

Sow these seeds in March and be rewarded with beautiful blooms.

Lots of flowers can be sown in March, including sweet peas, California poppy, cosmos, and ladybird poppies.


Hardy annuals can be sown direct outside, where they are to flower. These do best on ‘poor’ soil, so don’t enrich it with fertiliser. Half-hardy annuals such as dahlias and cleome, and perennials are best sown under glass at this time of year.

See our guide to 10 of the best dibbers for seed sowing and for further help, take a look at how to sow seed indoors. Our guide how deep to sow seeds is also useful.

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Finally, if you’re interested in growing your own food discover which vegetable seeds can be sown in March.

Here are just some of the flowers that you can start to sow in March.

Hardy annuals can be sown direct outside, where they are to flower.

Hardy annuals


Hardy annuals can be sown directly where they are to flower; prepare the ground well first, by clearing it of weeds and raking it to a fine tilth. Do not enrich the soil. Try Ammi majus, borage, clarkia, cornflowers, and Papaver commutatum ‘Ladybird’ (pictured).

Buy Ammi majus seeds from Suttons

Buy borage seeds from Thompson and Morgan

Buy cornflower seeds from Dobies

Buy Papaver commutatum ‘Ladybird’ seeds from Thompson and Morgan

Sweet peas

Sweet peas can be sown under cover from October to March. They like a long root run, so sow into deep pots or modules. Find out how to grow sweet peas.

Buy sweet pea seeds from Thompson and Morgan

But long, deep growing tubes for sweet peas on Amazon


Wildflower mixes


Annual flower mixes can be sown in March. As with hardy annuals, prepare the soil well by removing weeds and raking to a fine tilth, but do not enrich the soil.

Buy wildflower seed mixes on Amazon

Half hardy annuals


Half hardy annuals like cleome (pictured), antirrhinum, zinnia and cosmos can also be sown in March. They are not frost hardy, so must be sown under cover. Discover how to sow half hardy annuals.

Where to buy half hardy annuals online



Dahlias are tender perennials that will flower in their first year if sown in the greenhouse in March. In autumn, dig up the tuber to store over winter, or lift and store in cold areas. Find out how to grow dahlias from seed.

Buy dahlia seeds from Thompson and Morgan

Fast-growing perennials


Early spring is the ideal time to sow quick-growing perennials under glass. Try sowing echinacea, coreopsis, lupin or achillea and you may be rewarded with flowers this year. Find out how to grow quick-growing perennials from seed.

Buy echinacea seeds from Thompson and Morgan

Buy coreopsis seeds from Thompson and Morgan

Buy lupin seeds from Amazon


Buy achillea seeds from Dobies