How to Grow Wallflowers

Wallflowers are some of our most popular spring flowering plants. They are part of a group of plants we call Hardy Biennials, which means they grow and develop this year then flower next year. If you’d love masses of early flowers in your garden for wildlife, for cut flowers and beautiful plants to accompany your spring bulbs, then Wallflowers could be ideal for you.

I’m a great fan of planning ahead and making things easy in the garden. Sowing this summer will really pay off. Just sow a couple of packets of Wallflower seeds now for flowering next spring and you’ll be rewarded with lots of beautiful flowers and your local wildlife will thank you for it too! Wallflowers provide an early source of food for beneficial insects and many have the RHS Plants for Pollinators award too.

Wallflower seed is available in single colours such as White, Primrose, Orange and Red so it’s easy to select your favourite then plan a spring colour scheme for your containers, borders or entire garden. The photo below shows Primrose Dame and Fireking Wallflowers,

This year I’ve grown a mix of Sunset Wallflowers for the first time. They are quite lovely. For months in spring I had healthy, bushy plants with tall flower spikes and the most beautiful scented flowers. The seed is more expensive than most Wallflower seeds, but they are so amazing and worth that little extra, I think. Sunset Wallflowers are F1 Hybrids which produce top quality plants. Their flowers have variations of colour like a sunset, so they are really attractive. I’m growing them again for next spring as they were particularly lovely with our tulips and daffodils.

Wallflower ‘F1 Sunset Mixed’

This lovely new Wallflower produces clusters of scented flowers on strong stems. Each flower head is made up of many individual flowers which gives them a most attractive appearance. Blooms are produced early in the year at the same time as Tulips flower from March to the end of May. The Sunset Mix Wallflowers include a range of colours from rich purple and red, primrose, white and apricot to bronze and glorious rich orange flowers. They are jolly useful in the garden, in container or in a border with Tulips and other spring blooms and they’re lovely as a cut flower too. What’s more the RHS recommend Sunset Wallflowers as Perfect for Pollinators.

Grow a row of these in the cutting patch, as bedding plants or in bold groups in a mixed border in full sun for best results. Sunset Wallflowers cost a little more than other Wallflowers, but they are extremely easy to grow and very prolific giving you lots of flowers for not much time or effort!

Genus & Variety: Cheiranthus cheiri (was Erysimum cheiri)  F1 Sunset Mixed
Plant Type:  Hardy Biennial
Height & Spread: 40cm ( 16 inches ) tall x 30cm (12 inches) spread

How to Sow and Grow Wallflowers from Seed

  • Sow Seeds: Sow Wallflower seeds outdoors in a well-prepared seedbed when the soil is warm from the end of May/June to August. Alternatively sow in modules either indoors or outdoors but be careful to keep shaded and temperatures low. Wallflowers will not germinate well in heat. Keep seed trays moist and shaded. Germinates in 7-14 days at 15°C-18°C. Grow on then plant out six weeks later in August/early September. 
  • Thin/Plant Out:  Transplant to flowering position in autumn allowing plenty of space for the foliage and roots to develop before winter sets in. Allow a minimum of 30cm per plant.
  • Conditions Required: Wallflowers love moist but well drained soil. They prefer a site with plenty of sunshine and can also grow well in dappled shade. Sunset Mixed Wallflowers are great for containers too. Feed and water regularly to keep flower production going. 
  • Flower Production: Sow Wallflowers this summer for flowering next spring. Like many biennials, Wallflowers bloom early in the year, usually from March onwards. They are great for filling the gap before hardy annuals and perennials come into flower in June. Clusters of scented blooms are produced for up to three months until the end of May.
  • Picking: Cut flowers regularly and deadhead to make sure that your plants continue to produce new blooms. When cutting, strip the lower leaves, sear stem ends in boiling water for 20 seconds and place the cut flowers into a tall bucket of clean water. Allow to rest overnight before arranging. Wallflowers often last up to 10 days as a cut flower.
  • Planting Combinations: If you have the space, I suggest you grow plenty of lovely Wallflowers. You can never have too many! Wallflowers grow particularly well with Tulips, Daffodils and other spring flowering bulbs either in flower beds, borders or in large containers

Hot Weather Notes

One really important point to note from the Sowing and Growing Information above is that Wallflowers do not germinate well when it’s hot. As it’s hot all over the UK this week (25°C-35°C) and wallflowers prefer much cooler conditions (15°C-18°C) I recommend waiting until temperatures return to normal next week before sowing your Wallflower seeds.

Sow Direct or Sow in Modules/Seed Trays?

I usually hedge my bets by sowing directly into the ground AND sowing in trays or modules. We have plenty of wild creatures here including voles and mice, blackbirds and Mallard ducks which may damage or disturb tender young seedlings. We love all the wildlife… but I really love having plenty of home-grown plants too!  Positioning seed trays in a shady spot outdoors such as in the gap between rows of Sweet Peas or at the base of tall annuals such as Cosmos means that the seeds can develop and grow undisturbed AND it’s more likely that I’ll remember to water them too!

Are you growing Wallflowers from seed this summer?
Which is your favourite variety or colour… I’d love to know.

Happy Gardening! Gillian 🙂

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