Less widely used than annuals which flower and fade in one season, biennials develop their leaves one year and flower the next. Why bother including these in the garden? They are simply wonderful plants. Some, such as parsley, are grown for their foliage. Others are classic additions to the flower garden.
Foxgloves, Canterbury bells, rose campion, Queen Anne's lace and dame's rocket are all biennials. Many of these have perennial cousins under the same family name.
The gardener needs to do some research to be certain which is being planted. Hollyhocks reseed so vigorously that it may be of little use knowing whether you've planted a biennial one. By the way, "Summer Carnival" hollyhocks are annuals. If you want flowers the first year, add these to bloom while the others mature.
Two members of the sage family are beautiful biennials used for their foliage. Silver salvia has large, silver felted leaves that are far more dramatic than lamb's ears. The flowers are insignificant so I pinch them off immediately.
At five feet, clary sage provides an accent in the back row. The foliage has a scent of grapefruit and pine. The pink and purple flower spikes are long-lasting.
Like many subtle pleasures, biennials have to be appreciated for their unique contributions. My favorite, Sweet William, perfumes the late spring air with a clove scent. That quality, missing from many modern hybrids, is enough to merit inclusion in the garden. Sweet William is doubly blessed in also having variable, velvety, rich red and rose flower clusters. These cross-pollinate and self-sow, developing into meandering drifts over the course of a few seasons.
In the fast-paced annual world of instant, predictable gratification, biennials provide a refreshing reward for the few seasons it takes for them to become established. The first year, plant approximately half the number of plants desired. These typically develop rosettes of leaves over the first growing season. The following year, plant a second group of plants. While these are developing foliage, those planted the previous year will flower. They die after flowering whether or not permitted to go to seed. Allowing the seeds to ripen and self-sow begins a sustainable two year cycle during which there will be both flowers and foliage every season.
Biennials are great weavers. Their variability cannot be matched by bedding out annuals. They add a touch of informal cottage-garden charm wherever they are grown.
Editor's notes: Illustrations are by Ann Bartlett's artist daughter, Roxanne.
Master Gardener Ann Bartlett never lets lack of familiarity with a plant stop her from trying it in the ornamental beds around her home.