Sowing biennials is an easy and low-cost way to fill your garden with beautiful flowers. Biennials live for two years, developing roots and leaves in their first year and flowering in their second. After flowering, they set seed and die, but many will self-seed liberally, so once you have them in your garden, they’ll keep on appearing for years. We’ve put together a list of seven of our favourite biennials for you to sow. 

Sow biennials

1. Wallflowers (Cheiranthus cheiri) are a splash of colour in spring, and their fragrant flowers are an excellent early nectar source for pollinating insects. Sow under cover in February and March for planting in August and September, or sow outdoors in seedbeds in April and May and transplant in autumn or early spring. Wallflowers look great combined with tulips for a fantastic spring display.

2. Foxgloves (Digitalis purpurea) are ideal for dappled shade, producing tall flower spires in summer that are a favourite with bumblebees. Sow from April to July in a greenhouse or directly outdoors where they are to flower the following year. Plant out indoor-grown seedlings in autumn. Foxgloves self-seed liberally, so you’ll have flowers for years to come once they're established in your garden.

3. Columbine (Aquilegia vulgaris, also known as Granny’s bonnet) are beautiful cottage garden plants ideal for a cut-flower garden. Sow indoors from January to May or directly outdoors from February to June and September to October. Aquilegias self-seed very quickly.

4. Honesty (Lunaria annua) is famous for its silvery seedheads and its mauve or white flowers in spring and grows well in the sun or dappled shade. Start the seeds off in small pots in May and June, or sow them directly outdoors. The plants have long taproots, so they are best transplanted while still small. Honesty sown in summer will flower the following spring, providing an early food source for pollinators.

5. Hollyhocks (Alcea rosea) are tall and statuesque, fantastic for adding height at the back of a border, and bees love the big, colourful flowers. Sow outdoors in modules in summer and plant out in autumn for flowers the following year. Hollyhocks self-seed readily.

6. Sweet William (Dianthus barbatus) produces sweetly scented colourful flowers on neat mounds of delicate foliage, perfect for pots and window boxes.  Sow in seed trays or modules in a greenhouse in summer and plant out in autumn.

7. Hesperis matronalis (sweet rocket) flowers in late spring and early summer, producing pretty purple or white flowers very similar to honesty with a lovely scent most noticeable in the evenings. Sow outdoors in late spring and early summer for flowers the following year.

Now is the ideal time to start sowing biennials for next year, and we have a fantastic range of seeds in stock. You’ll find everything you need in our centre!