The biennials will bloom in early summer, when your eyes will need to be lifted from the yellowed leaves of daffodils and spent tulips
The success of a vase in full bloom, the momentum of a purchase that gives it instant color – these are the garden’s ways of attracting you. Biennials have a longer game; you need to sow now to receive your prize next year. But, man, it’s worth it, as these unpretentious rosettes of leaves grow to their glory: foxgloves, angelicas, eryngiums, echiums, sweet rocket, honesty, lots of bluebells, wild carrots, forget-me-nots, teasels, milk thistles, wallflowers or the dark purple-pink flowers of Delphinium requienii.
Behind all of this is an extensive root system, usually a common root that pierces even the good stuff, gathering supplies for the second-year explosion. The peak of the imposing flower that comes with these plants usually appears in early summer; think of the spectacular towers of a mullein or foxglove and its thousands of fine seeds. This is an evolutionary strategy to maximize seed production: if you flower in early summer, there is usually adequate soil moisture and less competition from larger plants for the sun.
The joy for the gardener is that these flowers appear when his eyes need to be lifted from things that are now wilting, such as spent tulips and forget-me-nots. Sprinkle some biennials in your layout and you will see, even before opening them, your eyes are drawn to them – the flower stem of a closed eryngium or angelica is as interesting as the final flourish. They tend to be good pollinating plants too.
Once established, you do not need to sow afterwards. They are generally prolific and self-propagate and move around their space as they see fit.
Sow covered now – they will need a little heat, 18-20 ° C – or outdoors by the end of the month. You can sow until July, either directly or in seed trays outside; if it is in trays, it will be necessary to fill it to be planted in the fall or the following spring. The first to be sown are the bluebells, angelica, foxgloves and aquilegias.
Or buy plants. If you buy plugs, such as clary sage, at naturescape.co.uk (wonderful bracts branched with beautiful white flowers), they may not bloom until next year, but they will bloom sooner than the seed ones. Or buy bigger, more expensive plants, from £ 6 to £ 12, that will bloom this year, like the Digitalis purpurea foxglove ‘Sutton’s Apricot’, with its soft damask pink flowers and mottled brown throat (from sarahraven.com). But those who spread seeds will have many more plants to play with for a fraction of the price.