Sow these flowers outdoors from July to August and then transplant to their final spot from October and November. Sow them in the garden from September to December.
What are biennial flowers?
Most biennial flowers are sown in (late) spring and summer and first need a growing season to bloom. The flowers are usually sown in the open ground in the right place of destination. Because of the late sowing, the seeds will germinate and grow, but will not flower. Often the above-ground plant dies in winter, while the root system remains intact. Flowering only comes after winter when the roots sprout again and form a new plant. This whole process often causes flowers to bloom early in spring. In most cases, these plants flower earlier than, say, annual plants that have to put all their energy into growing first. Depending on the species chosen, the flower may flower again the following year. In addition, biennial flowers can sow themselves, so blooms can be enjoyed every year.
How to sow biennial flowers?
Most biennial flowers are sown in late winter (February and March) or in the (late) summer. Transplanting is done very early in spring or in autumn, depending on the sowing period. Depending on the chosen sowing period, the seeds should be partly sown in a greenhouse instead of directly in the garden in a seedbed.
Types of biennial flowers
There are many different varieties of biennial flowers. Below is a small overview of the available biennial flowers:
- Millennial single-flowered mixed, Millennial low nanus compactus (mixed) and Millennial Pink Beauty are sown between May and July and then planted out/thinned in October. Ideal cut flower, suitable for heemtuin and verge.
- Iceland Poppy Exelsior (mixed), also known as poppy has two sowing periods: February to March (in a greenhouse) transplant in May and June or sow in July and August.
- Hollyhock Charter's (mixed) a very well-known biennial flower sown from May to July and thinned out/planted out in October and November.
- Forget-me-not (blue) and Forget-me-not Victoria (pink) seeds can be sown in a seedbed from June to August. Transplant and thin out in October and November.
- Foxglove (mixed) is sown from June to August and then thinned out/planted out in October and November.
- Violets seeds early sowings for annual flowers and late sowings for biennial flowers. Late sowing involves sowing from mid-July to mid-August in a seedbed for planting out in late autumn.
Tips and tricks
- Mix biennial and annual flowers
- Biennial flowers often bloom early in spring
- Ideal for planting in (late) summer
- Some biennial flowers resemble perennials: by not letting these grow to seed, an extra year of flowering can be encouraged