Foxglove

Foxglove is a plant that asks you to wait a full year before it shows you what it can do. The first season after sowing, you get a flat rosette of fuzzy, tongue-shaped leaves that sits low to the ground and does nothing dramatic. The second year, if the plant survives the winter, it sends up a four- to six-foot spike studded with tubular flowers — purple, white, peach, or apricot, speckled inside like a leopard's throat. Bumblebees crawl into them. The entire stem blooms from the bottom up over several weeks. Then the plant dies.

This biennial habit is what trips up most gardeners. A foxglove sown in spring of year one will not bloom until late spring or early summer of year two. If you want flowers every year, you need overlapping generations — either stagger sowings a year apart, or allow the plants to self-seed and naturalize. Left to their own devices, foxgloves tend to scatter seed freely; a mature colony maintains itself with new rosettes appearing each season while older plants flower and die.

The seeds are tiny and need light to germinate, so surface-sow them and press them into the soil rather than covering them. They can be started indoors or sown directly outdoors in late spring after the last frost. Transplant the seedlings when they have a few true leaves, spacing them about eighteen inches apart in a spot with dappled shade and moist, humus-rich soil. Full sun in hot climates tends to stress them; they prefer the filtered light at woodland edges where they evolved.

All parts of the plant are poisonous. The leaves, flowers, and seeds contain cardiac glycosides — the same compounds that were once used to make the heart medication digitalis. This matters if you have young children who put things in their mouths, or livestock that might browse the garden. A foxglove is not something to plant casually near a vegetable bed where a confused forager might mistake the leaves for comfrey or borage.

One common disappointment is crown rot, which tends to appear in winter when the rosette sits in waterlogged soil. The center of the plant turns brown and mushy, and by spring the rosette is dead. Well-drained soil prevents most cases; if your site tends to stay wet, a slight mound or raised bed can make the difference between a plant that survives the winter and one that rots.

In late summer of the blooming year, after the flowers fade, the spike will dry and split open to release thousands of seeds. If you want to control where the next generation appears, cut the spike before it shatters and shake the seeds where you want them. If you prefer a wilder look, leave the spike standing and let the wind decide.