All About Foxglove.

Nov 30, 2019

By Denise Seghesio Levine, U. C. Master Gardener of Napa County    

Many years ago, I spent a memorable Mother's Day weekend at a lovely bed and breakfast just outside of Mendocino. Sited on the west side of the highway, we could hear the waves crashing and knew our lodging was near the water, but it was too dark to see much when we arrived.

When the sun rose the next morning, we poured our hot coffee into big white mugs and walked out our door into the small private garden. We were intending to trek across the grass to see the sea when a glorious and amazing display of foxglove greeted us.

We saw a forest of nodding, bell-shaped blossoms climbing up waving stalks, rising from the large, flappy leaves surrounding the base of these whimsical plants. The tallest were adorned with abundant blossoms of deep purple with spotted throats. Others were colored soft apricot. More towers of bell blossoms were pure white while others were soft variations and blends of pinks, whites, lavenders and deep purples. 

Remembering this magical place and thumbing through one of my garden manuals, I was reminded that it is time to plant foxglove in the garden for flowers next spring.

Foxglove (Digitalis) is a biennial. Traditionally, a gardener would sow foxglove seed in the spring, or existing plants would self sow. Over the first year, the plants would develop their root systems and strong stems with basal leaves, rewarding the gardener with blooms the second summer.

To start foxgloves, scatter the tiny seeds on the surface of potting soil and keep moist until they germinate. Transplant carefully into individual pots and tend until spring when you can place them in your garden.

Now is a good time to wander the perennial aisle of your favorite nursery to get a head start with foxglove seedlings. Many varieties and colors are available in six-packs to plant for your own nodding forest next summer. Sizes range from over six feet tall to a small garden-friendly three-foot size.

You can also wait until spring, when you will find new hybrids that bloom the first year or seedlings that will bloom next summer.  But plants that go into the ground now will have all winter to develop root systems. Your planning will result in stronger, healthier, showier plants next year.

Read the label directions for spacing when you bring your plants home. Usually a spacing of 12 to 18 inches between plants provides enough room for foxglove to reach optimum size. Foxglove prefers acidic soil, and three to four hours of sun a day is typically enough to produce a showy display. Foxglove can be grown in dappled, shaded forest areas or bring interest and color to darker areas of the cottage garden or wild garden. They are deer proof, a bonus for many Napa Valley gardeners.

Native to the Mediterranean, other parts of Europe, Asia and the Canary Islands, foxglove are remarkably pest resistant. All parts of the plant are poisonous if ingested, which may have something to do with their resistance to creatures that munch.                                         

Wild foxglove is rarely bothered by pests. It is a very tough plant. But newer varieties can be susceptible to powdery mildew, mealy bugs, slugs and aphids. To avoid mildew, space plants far enough apart to provide air flow. Crowded plants are more likely to suffer. Remove dead leaves and debris from around plants to avoid slugs. If you find aphids, simply wash them off with a spray of clean water.

Foxglove readily self-sow if open pollinated and naturally grow in clumps or patches. That habit gives us a clue about how to plant them in our gardens. Taller specimens benefit from staking, although if they are healthy and protected from wind, staking may not be needed. Shorter varieties rarely need it.  

After most of the blooms are spent on the initial stalk, cut the stalk down. It will likely produce colorful side shoots.

Foxglove appreciate a generous application of mulch. (Think forest floor.) Add compost or feed shortly after planting and give them a booster of nutrients after the first bloom to reward them for a show well done.

When our first killing frosts arrive, remove any blackened leaves to eliminate hiding places for insects and slugs over the winter. If hundreds of seedlings start to appear after the first rains, thin or transplant extras. Crowded foxglove plants will be disappointing. 

And for the curious, digitalis comes from the Latin word for fingers. A blossom slips easily over a finger, like a little glove. Of course, if you are a fox, your whole paw should fit.

 The UC Master Gardeners of Napa County are volunteers who provide UC research-based information on home gardening and answer your questions. To find out more about upcoming programs or to ask a garden question, visit the Master Gardener website (http://napamg.ucanr.edu) or call (707) 253-4221 between 9 a.m. and 12 noon on Mondays, Wednesdays or Fridays.