Foxgloves (Digitalis spp.) are popular garden additions, instantly recognizable by their tall, striking spires of tubular flowers. Achieving these blooms requires precise timing, as the plant’s life cycle dictates when it will produce its floral display. Understanding when to introduce foxgloves, whether from seeds or established plants, is the primary factor in cultivating a successful show of color. Optimal planting windows ensure the plants have enough time to mature before their flowering phase.
Understanding the Foxglove Life Cycle
The common foxglove, Digitalis purpurea, is typically a biennial plant, meaning its life cycle spans two years. In the first year, the plant focuses on vegetative growth, producing a low-lying cluster of leaves known as a basal rosette. This foliage collects energy and builds a robust root system in preparation for the second year.
The flower spike emerges during the second spring and summer, after which the plant sets seed and dies. This cycle means you must plant new foxgloves annually if you want a continuous display of flowers every spring. Some newer cultivars, like the ‘Foxy’ or ‘Camelot’ series, have been bred to bloom in their first year, or are true perennial species.
Perennial foxgloves, such as Digitalis grandiflora or Digitalis × mertonensis, live for multiple seasons. However, the planting strategy for common biennial varieties must strictly follow their two-year schedule to guarantee flowers.
Timing for Starting Foxgloves from Seed
Starting foxgloves from seed requires careful timing to ensure the plant completes its first-year growth phase before winter arrives. The most reliable method for biennial varieties is outdoor sowing in the late spring or early summer, typically between May and July. This schedule allows the seeds to germinate and the seedlings to develop into a substantial rosette before the first hard frost of autumn.
When sowing seeds directly outside, scatter them thinly over the soil surface and gently press them down, as foxglove seeds require light to germinate. Covering the seeds with soil will prevent them from sprouting effectively. The resulting seedlings will spend the first growing season establishing their foliage and root system, ready to bloom the following spring.
For gardeners aiming for faster blooms, starting seeds indoors in the late winter or early spring is an option. Starting seeds about eight to ten weeks before the last expected frost date gives the plants a head start. These seedlings are then transplanted outdoors after the danger of frost has passed, which can sometimes lead to blooming by late summer of the first year, particularly with first-year-flowering cultivars.
Indoor-started seedlings should be transplanted to their final garden locations in the early autumn, about six to eight weeks before the first expected freeze. This autumn transplanting allows the young plants to anchor their roots in the cool, moist soil before winter dormancy. A well-established root system in the fall is the best assurance that the rosette will survive the winter and produce a flower spike the following spring.
Timing for Planting Nursery Starts or Transplants
Planting established foxglove nursery starts or transplants offers a simpler path to garden success than starting from seed. The two optimal times for transplanting established plants are early spring or early autumn. These periods provide the cooler temperatures and reliable moisture that foxgloves prefer for root establishment, minimizing transplant shock.
Planting in early spring, soon after the danger of a hard frost has passed, allows the plant to take full advantage of the entire growing season. Many plants purchased from garden centers in the spring are already one year old, meaning they have completed their rosette phase and will bloom in the same year. If you purchase a plant that is already flowering in the summer, it should be planted immediately and kept well-watered to help it settle in.
The best window for transplanting young starts is early autumn. Planting in the fall gives the root system several weeks to grow and secure itself before the ground freezes. This preparation ensures the plant is fully settled and ready to initiate vigorous growth when spring arrives, leading to a robust bloom. Avoid transplanting small seedlings in late fall, as they may not have the strength to survive a harsh winter outdoors.