Biennials are plants that spend their first year making roots and foliage, and then, in their second year, bloom and make seeds before dying. We’re comfortable with annuals and perennials, but biennials get short shrift.
If you’re creating a cottage garden or a potager, there’s no way to avoid biennials. Foxgloves, hollyhocks, sweet William, rose campion, honesty, forget-me-nots, dame’s rocket, and angelica, are all biennials.
I can’t imagine my garden without these early and mid-spring workhorses, especially those that bloom after bulbs finish, but before most annuals get going, but I get push back from people on them. Folks resent the plants for not lasting longer since annuals only last a year, but I think folks balk at their cost and feel like they’re buying a perennial that’ll die next year.
I think these folks are missing the point. The brilliance of biennials is not just their impact, but their ability to self-seed vigorously. Follow two rules and you can have foxgloves forever. First: leave past-bloom flowers in place long enough for their seeds to cure and fall. Second: don’t disturb those fallen seeds when adding new plants, or inadvertently mistake their seedlings for weeds and “tidy them up” during spring or fall clean ups.
There are a few ways to do this. Let a second-year plant go to seed then wait two years for those seedlings to bloom. Or plant a second ready to bloom plant the second year, so you’ll never have a year without blooms, and off you go.
For those of you who still are resisting, you can also start them from seeds. It’s great if you have a greenhouse, but if you, like I, don’t, they’re easy to direct sow, and now’s the time to do so. Find an unplanted area, space in a vegetable bed, or grab a few pots, and evenly distribute their seeds over the top of the soil.
The more room each seed has, the less you’ll need to thin out seedlings to ensure each has enough light and air. A lot of biennial seeds are tiny, so it helps to mix them with a few handfuls of clean, dry sand before you sow to help disperse them more evenly. And many need light to germinate, so make sure you check your seeds’ needs. When the seedlings are large enough to transplant, you can do so all season, right up until a month or two before our first frost (mid-October) which gives them time to root in before winter.
I tend to be lazy and leave mine in place (although pot-grown seedlings get moved into my empty veggie beds to overwinter.) I prefer to wait until spring, when garden gaps are obvious, to find them homes. I also move self-sown seedlings around, spreading their wealth around the garden.
Some biennial seeds need more preparation than others. Hollyhocks from a package need to be soaked in warm water for 12 hours before planting to mimic the experience they’d have had if the seeds had come from plants and just fallen to the ground in the fall. I threw down a single package of dame’s rocket seeds, randomly, years ago and every May since my garden has been filled with a riot of soft lavender and white clouds. I also collect my own foxglove seeds in fall by watching until their seed pods begin to crack open. I then carefully cut the flower stalks and slide them into bread bags, tips first. I hang these bags in the garage, or the house to let them fully ripen. Once the ripened seeds fall to the bottom of the bags, I take them back outside to scatter. I know I’m a garden nerd, but the hundreds of babies you get from just one flower stalk is bananas.
A final thought — many vegetables are biennials we’ve decided to harvest in their first year. Carrots left in the ground have gorgeous Queen Anne’s lace like flowers, and two-year-old parsnips flaunt such enormous, citron green blooms that I grow mine as cutting flowers!
Paige Patterson invested heavily in sweet peas seeds this year.
