This month you should be planning your lovely summer flower display. A cheap way of providing a mass of colour is to sow seeds. There are many flowers which provide an important source of nectar for butterflies and bees and if you grow enough you can also bring some into the house as cut flowers for beautiful arrangements.

You can either wait for a few months and sow directly into the garden or get them going indoors now. Hardy annuals will survive the frosts of winter so can be sown directly outside between April and September. Half-hardy annuals are less robust so must be sown outside when the frosts are over in May. Check each seed packet for specific dates and instructions.

Sow seeds thinly into soil of a fine consistency, cover lightly with compost and water regularly. If necessary thin out once they reach 2.5cm tall as the plants will thrive better with space around them so they don’t have to compete for light, water and nutrients.

Sowing seeds inside now, in trays or pots and placing on a sunny windowsill or in a propagator will give plants a head start so they flower earlier. Once the weather is warm enough they can be planted outside in a sunny spot in moist but well-drained soil.

There are many places to obtain seeds but renowned gardener Sarah Raven’s website specifically focusses on plants that are good nectar and pollen sources for pollinators. 

Seeds are available from her website for the following selection of plants that make great cut flowers and are popular with butterflies such as Common Blue, Red Admiral, Small Tortoiseshell and Comma.

Tithonia and Scabious Collection 

  • Mexican Sunflower Tithonia rotundifolia ‘Torch’ has orange flowers 12-14 weeks from spring sowing, and is 1.2-2.5m high. It is a half-hardy annual which looks great when paired with the hardy annual Scabious Scabiosa atropurpurea 'Black Cat'. This has dark crimson flowers from June to August, 10 to 12 weeks after spring sowing, and reaches a height of 100cm

Cornflower Centaurea cyanus ‘Black Ball’ has dark crimson flowers from May to July, 10 to 12 weeks after spring sowing, and reaches a height of 90cm. ‘Blue Boy’ has bright blue flowers from June to August.

The Ultimate Cosmos Collection 

  • This contains Cosmos Cosmos bipinnatus ‘Purity’, ‘Dazzler’, ‘Psyche White’ and ‘Click Cranberries’. These are 1m-tall half-hardy annuals with white or carmine pink flowers from June to November, 12 to 14 weeks after sowing.

Butterfly Flower mix

The following Butterfly Flower Mix makes a lovely bouquet

  • Annual Viper's-bugloss Echium vulgare ‘Blue Bedder’ has brilliant blue flowers from May to September, 12 to 14 weeks after sowing, and reaches a height of 45cm. It is a hardy annual.  
  • Toadflax Linaria purpurea ‘Canon Went’ has pink flower spikes from May to September and a height of 75cm. It is a hardy perennial.
  • Verbena bonariensis has purple flowers on 1.2m-tall stems from July to November, 14 weeks after sowing. It is a short-lived perennial grown as a hardy annual and will lightly self seed.

As some of these plants are quite tall, they might need staking.

It is very satisfying raising plants from seed right through to flowering and you can feel very proud of supplying the butterflies with such great nectar sources too. 

Happy Gardening!

The Secret Gardener

Images copyright Jonathan Buckley