The best seeds to sow in March

Hardy annuals are robust flowers that can be sown outside in March. They prefer soil that hasn’t been enriched with fertiliser, so you just need to prepare the ground by removing weeds and raking the earth to a fine consistency. Sow hardy annuals directly where you want them to flower. Our favourites are borage, clarkia and cornflowers.

Not quite as resilient as hardy annuals, it is best to sow half-hardy annuals under cover in March. They can then be moved to a patio or cold frame once the likelihood of frost has passed. For the first week, it’s best to bring them indoors overnight to give them a chance to adjust to the change in climate. After a week they can be planted outside. Our favourite half-hardy annuals are cleome, antirrhinum and zinnia.

If March brings particularly warm weather, there are a few half-hardy annuals that can be sown directly outside, such as French marigolds and nasturtiums. Both have vibrant leaves which bring a bright burst of colour to your garden.

Not only are wildflower mixes a delight to behold, but they are also very easy to sow. Once the frosty days have passed, remove weeds and rake the soil to a fine consistency, then sprinkle the seeds directly onto your soil. Avoid enriching with fertiliser as these wildflowers grow most successfully in unfertilised soil.

Perennials are cold-hardy plants that return each year. They tend to bloom for one season a year, but when grown in favourable conditions they can blossom for many years. 

Dahlias are popular perennials that flower in their first year when sown in a greenhouse in March. When autumn arrives, add a thick layer of mulch to provide extra insulation during the cold winter months. Or dig up the tubers and store them in an unheated place, protected from frost.

March is also a great time to sow quick-growing perennials under glass. Some of our favourite fast-growing perennials include echinacea, coreopsis and lupin.