TWICE AS NICE

Baffled by biennials? Here's how to grow 10 worthwhile kinds

- DARYL BEYERS

The purple and white flower spikes of biennial foxgloves add whimsy to this cottage-style planting.

As a landscape designer and garden maker, I’m often asked by clients to replicate certain types of gardens. One common request is for a cottage-style garden filled with flowering plants that look wild and unkempt but are nonetheless carefully considered, placed and planted. One of the best ways to achieve this laissez-faire look is to use multiple layers of plants, including flowering shrubs and perennials, and then, to add depth and character, introduce the best of the best when it comes to unpredictability and seasonal surprise: biennial flowers.

Most gardeners eschew biennials because they aren’t permanent. Some think they were cheated when their foxgloves suddenly disappeared the year after they were planted, not realizing that they bought the plant in the second year of its two-year life span.

HOLLYHOCKS (ALCEA ROSEA)

The first year of a biennial starts with a seed that grows through the season, making just roots and leaves. When winter comes, the shoots die back, but the roots survive. The plant reemerges the following spring, just like a perennial, but during this second year it grows larger and ultimately forms flowers, fruits and finally seeds. The plant then dies, but if the seeds are allowed to scatter on the soil, they sprout anew come spring.

If the cycle is broken at any point— the flower stalks removed from the plant before the seeds form, or the dispersed seeds raked or blown out of the beds—the biennial will disappear.

Savvy gardeners understand this two-year cycle and find ways to include biennials, taking advantage of the random charm and variety they bring to any flower bed. Here are some of the best to try in your garden.