Foxgloves (Digitalis) are celebrated garden plants known for their tall spires of tubular blooms, typically in shades of purple, pink, and white. They add a dramatic vertical element to any landscape. The direct answer to whether foxgloves self-seed is a resounding yes; they are notably prolific self-sowers. This ability to disperse seeds freely is the primary natural mechanism ensuring their continued presence in the garden.
How Foxgloves Disperse Their Seeds
The physical process of self-seeding begins after the plant’s flowering period, typically from late summer into the fall. As the colorful blooms fade, they dry and develop into small, rounded, hard seed capsules along the tall flower stalk. Foxgloves are incredibly successful at reproduction, with a single mature plant capable of producing an estimated one to two million minuscule seeds.
Once the capsules are fully mature and dry, they split open, ready to release their contents. The seeds are then dispersed primarily through a passive mechanism: they simply fall to the ground directly beneath the parent plant or are shaken out by the movement of the tall stalk. Wind and rain cause the dried stalk to sway, scattering the seeds over a small radius, leading to a cluster of new seedlings near the original plant. These seeds require light to germinate, meaning they must remain on the soil surface rather than being buried.
Biennial Life Cycle and Garden Presence
The prolific self-seeding of foxgloves is deeply connected to the biennial life cycle of the most common species, Digitalis purpurea. A biennial plant completes its life cycle over two growing seasons, starting with the germination of the seed. During the first year, the seedling establishes itself and grows a low, leafy collection of foliage known as a rosette.
The plant then overwinters in this rosette form, storing energy and building strength for the following season. In the second year, the plant “bolts,” sending up the characteristic tall flower spike, producing seeds, and then dying once its reproductive cycle is complete. This natural death is why self-seeding is important; the plant must successfully reproduce to ensure its lineage continues.
When gardeners allow this self-seeding process to occur, the plants create a perpetual display, giving the appearance of a perennial flower. New seedlings appear every year, with Year 1 rosettes growing alongside Year 2 flowering plants. This continuous cycle, often called “staggered germination,” is what creates the desirable “naturalized” look in a garden, ensuring a fresh flush of blooms each summer without the gardener having to sow new seeds.
Managing and Transplanting Volunteer Seedlings
The abundance of self-sown plants, often called “volunteers,” means gardeners typically need to manage their location and density. Identifying these new plants is straightforward, as they appear as small, low rosettes of leaves on the ground. While some can be left to grow where they fall, thinning or transplanting is often required to prevent overcrowding and ensure each plant has enough space to develop into a healthy, full-sized flower.
Volunteer seedlings are best moved during their first year of growth while they are still in the rosette stage. The most successful times to transplant are either in the early fall, allowing them to establish roots before winter, or in the early spring, before they begin their second-year growth spurt towards flowering. These young plants have shallow root systems, making them relatively easy to lift with a trowel, taking care to keep the rootball intact.
When relocating the seedlings, choose a spot with moist, well-draining soil and partial shade, which mimics their preferred woodland edge environment. Space them about 12 to 18 inches apart to allow for proper air circulation and growth. If a gardener wishes to prevent self-seeding altogether, the tall flower stalk should be “deadheaded,” or cut down, immediately after the blooms fade but before the seed capsules have a chance to dry and split.