Beauty of biennials: they take a little longer, but they’re worth the wait
Some of the prettiest garden plants are biennials and there’s a great range available, so get them in the ground now for non-stop flowers next year, says Hazel Sillver
BIENNIALS are flowering plants that take two years to complete their life cycle. They produce foliage in their first year and then flower in their second, before setting seed and dying. So, enjoying the colourful spires of foxgloves, the architectural globes of angelica and the almond scent of wallflowers on the air means being organised. They must be sown or planted in 2021 in order to produce flowers in 2022.
Some biennials can still be grown from seed at this time of year, but most are best purchased as ready-grown seedlings or plants to put in the ground now or in early autumn. Choose wallflowers and honesty to brighten the garden in spring, sweet Williams and sweet rocket to fill May and June with colour and scent, and the butter-yellow blooms of evening primrose and giant mullein to light up borders during July and August.
If there’s a gap to fill at the back of the border, several biennials reach impressive heights. Angelica gigas has wonderful beetroot-coloured umbel flowerheads on 6ft (1.8m) stems. This plant attracts everything that buzzes, so don’t grow it beside a patio. In mild areas, the tower of jewels (Echium pininana) produces spires of electricblue flowers that bees flock to. But the ultimate triffid is Onopordum nervosum, a thistle with spiky silver-white foliage that reaches a statuesque 10ft (3m) tall.
Shade lovers
For shade or semi-shade, forget-menots and foxgloves are invaluable stalwarts. But for something a bit different, try the superb variegated white honesty (Lunaria ‘Alba Variegata’), glowing golden-lime Smyrnium perfoliatum or Chinese forget-me-not (Cynoglossum amabile), which has tall stems and reflowers if cut, making it great for the vase.
Several short-lived perennials are often grown as biennials, including black hollyhock (Alcea rosea ‘Nigra’) and rose campion (Lychnis coronaria), both of which are great border plants; and stocks, such as Matthiola perennis ‘Alba’ and M. incana ’Pillow Talk’, that release beautiful perfume on summer evenings.
The range of biennials on offer is huge, and if you vary the ones you grow every year it will mean that your garden is never dull.