When to plant: Last year (not a joke; these are biennials)
What Foxglove (digitalis) means: the Anglo-Saxon name was “foxes glofa” (“the glove of the fox”) because it looked like it would fit a fox’s paw. The Latin name, “digitalis” comes from the word “digit” or finger, since it was easy to fit a finger inside the flowers. The plant is native to Europe, the Mediterranean region and the Canary Islands. Digitalis was eventually found to contain a powerful heart-stimulating drug, although it was quickly discovered that there was a thin line between a therapeutic dose and a fatal one. The amount of the drug varies depending on the part of the plant and even the time of year.
When it blooms: early summer, although in 2015 hybrids were developed for hardiness zones 6, 7 and 8 that are perennial and bloom all summer. See Foxlight Series.
Where to plant foxglove: Moist areas in full sun to part shade.
Biennials are not annuals. And they are not perennials. Gardeners plant a seed one year and try not to ripe out the green flowerless stalk that grows, thinking it’s a weed.
Then they try to remember where they planted those seeds the previous year, so they don’t pull the same plants up the next year, because that’s the year they are actually going to form flowers.
The third year? They are gone.
What kind of plant is that?
That’s a biennial. Hollyhocks are biennials. So are black-eyed Susans and sweet Williams. Luckily, most of these plants are proficient at self-seeding. Foxglove seedlings appear in two-to-three weeks. And guess what that means? Luckily those seedlings are the foxgloves’ first year, meaning that next year they will bloom.
Once established in their happy place, foxgloves keep going. A lucky gardener will never have to think about them again. They will pop up in new places, and with a mix of foxgloves, in new colors.
The following is according to Burpee, which sells Foxglove seeds and plants. Among the type of speckled foxglove seeds they sell is Excelsior, above, which grows 5 feet tall and comes in pink, rose, purple, cream, primrose and white. Foxgloves, along with delphiniums, are the stars, the bones of the classic cottage garden. Burpee says:
Direct sow in rich, moist soil in part shade to full sun after danger of frost. Remove weeds and work organic matter into the top 6-8 inches of soil; then level and smooth. Sow seeds evenly and thinly and barely cover with fine soil. Keep evenly moist. Seedlings will emerge in 14-21 days depending on soil and weather conditions. Thin to stand about 18 inches apart when large enough to handle.
Keep weeds under control during the growing season. Weeds compete with plants for water, space and nutrients, so control them by either cultivating often or use a mulch to prevent their germination. Mulches also help retain soil moisture and maintain even soil temperatures. An organic mulch of aged bark or shredded leaves lends a natural look to the bed and will improve the soil as it breaks down in time. Always keep mulches off a plant’s stems to prevent possible rot.
Careful watering is essential in getting plants off to a good start. Water thoroughly at least once a week to help new roots grow down deeply. Soil should be damp at about 1 inch below the soil surface. You can check this by sticking your finger in the soil. Water early in the morning to give all leaves enough time to dry.
One inch of rain or watering per week is recommended for most perennial plants. You can check to see if you need to add water by using a rain gauge.
Until plants become established, some protection from extreme winds and direct, hot sunlight may be necessary. Good air movement is also important. After new growth appears, a light fertilizer may be applied. Keep granular fertilizers away from the plant crown and foliage to avoid burn injury. Use low rates of a slow release fertilizer, as higher rates may encourage root rots.
In general, there is no need for staking.
Mulch after the ground freezes in fall to prevent heaving in winter. Evergreen branches work well for this. Remove mulch in spring when new growth appears.
Not as popular as the taller and fancier biennial, annual foxgloves, seen above, are also available from Burpee. The problem is their long growing season. The seeds must be started indoors, about three months before the last frost. The seedlings can then be transplanted outdoors.
Some people find it easier to simply buy foxgloves ready to bloom, or first year plants, especially at the end of the season. Those can be tucked into empty spots in the garden, where a gardener will be assured of a spectacular spike the following year.
In 2015, an interspecific, trademarked hybrid was released. Only one is widely available, because it has its plant patent, the Foxlight series Ruby Glow.
These foxgloves are not for those of us who live north of Washington DC.
There were three colors bred in 2015, the Foxlight series Ruby Glow, the Foxlight series Rose Ivory and the Foxlight series Plum. The latter two are PPAF (plant patent applied for) and will be available when the patent is granted. These will self-seed, but because they are hybrids they will not necessarily produce true seedlings.
The Foxlight series will not produce the tall spires of the Burpee Excelsiors. The Foxlight plants are 18 inches tall; with flowers two feet tall. But the flowers are good as cutting flowers, and the foxglove, if flowers are cut, will continue producing blooms all summer.
These foxgloves would love great in containers, and as such could be grown even further north, if it would be possible to keep soil conditions consistently moist but not wet.
Ruby Glow, above, is described as having a bold and deep ruby glow color, flowers facing outward for better show. These foxglove do not have the beautifully speckled throats of the more spectacular foxglove, nor the imposing height, but they make up for it by their long bloom season.
The Dalmatian series of foxgloves is fast-growing, and thus qualifies as a perennial. The flowers are pure, single color, but still have freckled throats. One of our favorites is the Dalmatian Peach, above, which opens pinkish peach and lightens to soft peach. The Dalmatians will flower again the second year if you remove the spent flowers. The best bet it to remove some, and let others go to seed. These will grow up to four feet tall, in four months from planting, and will survive winters down to hardiness zone 5.
The Camelot series of foxglove brings a more normal foxglove season to the deep south. In Louisiana, people might grow the regular foxglove from October to May, because it would die in the heat of the summer. But the Camelot series will survive the heat and humidity of a Louisiana summer, so foxglove can be planted in spring there. Yet the Camelot also grows spectacularly in hardiness zones 5 through 9.
The Camelot series, which grows 3 to 4 feet tall, was developed in 2003, and Camelot White (above) has become one of the most popular varieties. In fact, planting instructions suggest that gardeners remove most of the flowers so that too many seedlings don’t take over the garden. That’s what we like to hear!
Because foxglove grow in moist soil, and in partial shade, they are prone to fungus and rot.
Anthracnose: This is a fungus disease causes brown spots with purple edges on the leaves. The spots turn black in the center, leaves become yellow, dry and fall off. The fungus overwinters in diseased plant debris. Burpee Recommends: Avoid overhead watering which can spread the fungus spores. Keep a clean garden, remove and discard all diseased plant material. Use a mulch to prevent spores from splashing from the soil onto plants.
Crown Rot: This attacks plants at the base, turning them brown and spongy. White fungal spores may develop at the base of the plant. The crown deteriorates, leaves turn yellow and wilt. Burpee Recommends: Ensure that plants have good drainage and are not overcrowded. Remove infected plants.
Damping Off: This is one of the most common problems when starting plants from seed. The seedling emerges and appears healthy; then it suddenly wilts and dies for no obvious reason. Damping off is caused by a fungus that is active when there is abundant moisture and soils and air temperatures are above 68 degrees F. Typically, this indicates that the soil is too wet or contains high amounts of nitrogen fertilizer. Burpee Recommends: Keep seedlings moist but do not overwater; avoid over-fertilizing your seedlings; thin out seedlings to avoid overcrowding; make sure the plants are getting good air circulation; if you plant in containers, thoroughly wash them in soapy water and rinse in a ten per cent bleach solution after use.
Leaf Spot: This causes reddish brown to black spots on leaves. The spots can grow and eventually kill the plant if untreated. Burpee Recommends: Remove affected foliage. Avoid overhead watering. Contact your Cooperative Extension Service for recommendations.
Verticillium wilt: This soil borne fungus causes wilting of the leaves and stems on several branches. Leaf margins cup upward, leaves turn yellow and drop off. It enters through the roots, migrating up the stem and plugging a plant’s transport vessels. It is transmitted in the soil. It can also be spread by water and tools. Burpee Recommends: Remove plants and do not plant in the area for several years.
Below are a few common pests that can cause problems for the foxglove.
Aphids: Greenish, red, black or peach colored sucking insects can spread disease as they feed on the undersides of leaves. They leave a sticky residue on foliage that attracts ants. Burpee Recommends: Introduce or attract natural predators into your garden such as lady beetles and wasps who feed on aphids. You can also wash them off with a strong spray, or use an insecticidal soap.
Japanese Beetles: Burpee Recommends: Hand pick early in the morning into a bucket of soapy water.
Mealybugs: Mealybugs are 1/8 to ¼ inch long flat wingless insects that secrete a white powder that forms a waxy shell that protects them. They form cottony looking masses on stems, branches and leaves. They suck the juices from leaves and stems and cause weak growth. They also attract ants with the honeydew they excrete, and the honeydew can grow a black sooty mold on it as well.Burpee Recommends: Wash affected plant parts and try to rub the bugs off. They may also be controlled by predator insects such as lacewings, ladybugs and parasitic wasps. Check with your Cooperative Extension Service for pesticide recommendations.
Slugs: These pests leave large holes in the foliage or eat leaves entirely. They leave a slime trail, feed at night and are mostly a problem in damp weather.Burpee Recommends: Hand pick, at night if possible. You can try attracting the slugs to traps either using cornmeal or beer. For a beer trap, dig a hole in the ground and place a large cup or bowl into the hole; use something that has steep sides so that the slugs can’t crawl back out when they’re finished. Fill the bowl about ¾ of the way with beer, and let it sit overnight.
In the morning, the bowl should be full of drowned slugs that can be dumped out for the birds to eat. For a cornmeal trap, put a tablespoon or two of cornmeal in a jar and put it on its side near the plants. Slugs are attracted to the scent but they cannot digest it and it will kill them. You can also try placing a barrier around your plants of diatomaceous earth or even coffee grounds. They cannot crawl over these.
Spider Mites: These tiny spider-like pests are about the size of a grain of pepper. They may be red, black, brown or yellow. They suck on the plant juices removing chlorophyll and injecting toxins which cause white dots on the foliage. There is often webbing visible on the plant. They cause the foliage to turn yellow and become dry and stippled. They multiply quickly and thrive in dry conditions. Burpee Recommends: Spider mites may be controlled with a forceful spray every other day. Try hot pepper wax or insecticidal soap. Check with your Cooperative Extension Service for miticide recommendations.
The best news? Deer and mice won’t touch them.