Does everyone know what a biennial plant is? It’s a plant that spends its first year of life building a substantial root system and a basal rosette of foliage. In its second year, it will have the resources to support a season of massive blooming and seeding. After having done its job, it dies away, leaving the future of its kind to the new generation of seedlings it has created.
Biennials are monocarps – plants that die after blooming. A famous example of a monocarp that lives far longer than two years is the Century Plant (Agave sp.). By the way, Eve’s 27 year old Agave has finally decided to bloom this year! The dark purple bloom stalk, still sheathed, first erupted on April 29, and is now 30″ tall. We’ll keep you posted on its progress, photos and all.
We do notice that some gardeners shy away from biennials, and we want to encourage you to try these hard-working and beautiful category of plants.
Why is this a boon to the gardener? Because that massive display in the second year is usually spectacular! In many cases, this prodigious bloom will provide lots of cut flowers, and many will bloom for months on end. There are plenty of familiar old-fashioned biennials, like biennial Foxgloves (Digitalis purpurea), Hollyhocks (Alcea rosea), Ratibida columnifera (Prairie Coneflower/Mexican Hat), and Sweet William (Dianthus barbatus).
Here are some less familiar but highly garden-worthy biennials, many of them show-stopping!
Campanula medium – Canterbury Bells
Campanula ajugifolia, topaliana, hoffmanii
Seseli gummiferum – Moon Carrot
Verbascum bombyciferum – Wooly Mullein
Verbascum olympicum – Greek Mullein
Papaver triniifolium – Armenian Poppy
Campanula pyramidalis – Chimney Bellflower
Ipomopsis (Gilia) aggregata – Skyrocket
Ipomopsis (Gilia) rubra – Scarlet Gilia, Standing Cypress
Asphodeline damascena – Damascus Ithuriel’s Spear
Erysimum – Wallflower
Michauxia – Catherine Wheel
Mentzelia decapetala – Evening Star
Mentzelia nuda – Branched Evening Star
Machaeranthera pattersonii – Patterson’s Tansy Aster
Machaeranthera bigelovii – Bigelow’s Tansy Aster
Thelesperma – Navajo Tea, Greenthread