Friday 18 October 2019

Diarmuid Gavin: Sow biennial seeds now for colourful displays next year

Sow biennial seeds now for colourful displays next year

Sweet William
Sweet William

Diarmuid Gavin

Spring is the time we associate with sowing seeds, especially annuals - those plants which germinate, flower and die all in the same year.

However, there is another category of plant - biennials - which can be sown in early to mid-summer. Biennials take two years to complete their life cycle - sow now and they will germinate and form a rosette of leaves this year which will be followed by a spike of flowers next spring. The plant will then set seed and die off in the autumn and winter.

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Many of our most loved flowers are in this category such as foxgloves, forget-me-not, Queen Anne's Lace, Sweet Williams and wallflowers. So if you'd like to see these in your garden next year, harvest or buy some seed now and get propagating. You won't get the quick gratification that annuals provide but with a little patience and dedication you will be rewarded with colourful and often fragrant flowers that both you and our friendly bees and butterflies will enjoy.

Oenothera biennis

- or evening primrose is a tall biennial up to 1.5 metres with yellow flowers. These only open at night to release their fragrance - this is done in order to attract night-time pollinators such as moths. It's a good choice for poor soil so long as it's well-drained and in the sunshine and once you have it, it will self-seed happily so great if you like a more informal look in your garden. It's hugely popular as a herbal remedy - the oil in the seeds contain fatty acids that are used to help with hormonal and other health issues.



- who doesn't like a foxglove (pictured)? Tall elegant spires covered in bell-shaped blossoms and if you look closely, you will often see the hairy behind of a bumble bee buried within, nuzzling away for nectar. The flowers form capsules - open these and you will see tiny brown seeds. You can scatter these straight into the soil but you'll need to be eagle-eyed when weeding to avoid removing the subsequent seedlings. Alternatively you can propagate them in seed modules or pots - scatter on the surface of pre-wetted seed compost and don't cover as they need the light to germinate.

Lunaria annua

- otherwise known as Honesty - is grown as much for its attractive purple flowers in spring as for its beautiful disc-shaped translucent silver pods which are a florist's favourite in their dried form. There's also a lovely white variety 'albiflora'. Sow well spaced in seed trays where they will take about a fortnight to germinate.

Dianthus barbatus

- or Sweet William (pictured). Like all members of the Dianthus family, it's all about that delicious sweet clove scent.

Sweet William

The Duchess of Cambridge included a white version in her wedding bouquet, a delightful romantic gesture to her new husband. Otherwise they come in bright pinks and red and there's a gorgeous dark variety called 'Sooty' with very dark ruby blossoms and chocolate-coloured foliage. Sow seeds in early summer and plant out to final positions either in autumn or next spring into fertile soil, adding some slow release fertiliser to the planting hole. Sunshine is best for flower production and they make excellent cut flowers.

Echium pininana

- or Giant Viper's Bugloss is one of my favourite plants, great for adding drama and excitement as they grow several metres tall. I have them growing at the front of the house where they happily self-seed. I have noticed that they sometimes take an additional year to complete their life cycle - the middle year they gather their strength to send up these enormous spikes covered in violet blue flowers. I can think of no other plant that attracts the same amount of bees - the hum of the bees buzzing is the sound of summer for me!


Top Tip

Make sure Lunaria annua are planted in their final flowering positions in September/October so that they have time to establish roots.

Irish Independent

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