Learn About Foxgloves
How to Sow
How to Sow and Plant
Foxglove may be grown from seed sown early indoors and transplanted outside after frost, or sown directly in the garden in summer, or planted as a potted plant.
Sowing Seed Indoors:
- Sow seeds indoors in 8-10 weeks before the last frost.
- Barely cover with seed-starting formula.
- Keep the soil moist at 60-65 degrees F.
- Seedlings emerge in 14-21 days.
- Keep evenly moist.
- As soon as seedlings emerge, provide plenty of light on a sunny windowsill or grow seedlings 3-4 inches beneath fluorescent plant lights turned on 16 hours per day, off for 8 hours at night. Raise the lights as the plants grow taller. Incandescent bulbs will not work for this process because they will get too hot. Most plants require a dark period to grow, do not leave lights on for 24 hours.
- Seedlings do not need much fertilizer, feed when they are 3-4 weeks old using a starter solution (half strength of a complete indoor houseplant food) according to manufacturer’s directions.
- If you are growing in small cells, you may need to transplant the seedlings to 3 or 4 inch pots when seedlings have at least 2 pairs of true leaves before transplanting to the garden so they have enough room to develop strong roots.
- Before planting in the garden, seedling plants need to be “hardened off”. Accustom young plants to outdoor conditions by moving them to a sheltered place outside for a week. Be sure to protect them from wind and hot sun at first. If frost threatens at night, cover or bring containers indoors, then take them out again in the morning. This hardening off process toughens the plant’s cell structure and reduces transplant shock and scalding.
Planting in the Garden:
- Select a location in full sun to part shade with moist, organic soil.
- Prepare the bed by turning the soil under to a depth of 6-12 inches removing any debris, and lightly raking as level as possible.
- The addition of organic matter (leaf mold, compost, well-rotted manure) benefits all gardens and is essential in recently constructed neighborhoods.
- Plant on a cloudy day or in late afternoon to reduce transplant shock.
- Dig a hole for each plant, approximately 18 inches apart large enough to amply accommodate the root ball.
- Unpot the plant and gently loosen the root ball with your hands to encourage good root growth.
- Place the top of the root ball even with the level of the surrounding soil. Fill with soil to the top of the root ball. Press soil down firmly with your hand.
- Thoroughly water and apply a light mulch layer on top of the soil (1-2 inches) to conserve water and reduce weeds.
Sowing Directly in the Garden:
- 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.
How to Grow
How to Grow
- 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. Christmas tree branches work well for this. Remove mulch in spring when new growth appears.
- Leave some flowers on the plant to set seeds, then collect and spread them wherever you want new plants.
- Foxgloves are classic late-spring plants for cottage gardens and other informal plantings. They are at home in woodland gardens and make attractive accents at the back of mixed borders.
- Combine foxgloves with bleeding hearts, hardy geraniums, astilbes, catmints, and bellflowers in a bed or border. In a woodland garden, combine foxglove with hostas, ferns and wild blue phlox.
- Foxgloves make excellent cut flowers.
- Note that foxgloves are poisonous if eaten.
Common Pests and Problems
Common Disease Problems
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.
Common Pest and Cultural Problems
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 full 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.
Is foxglove toxic to people and pets? Yes, foxglove is toxic when eaten.
Does foxglove seed itself? Yes, foxglove is a biennial and tends to sow itself after flowering. You can move the rosettes to wherever you want them in your garden and they should bloom the following year.
Why didn’t my foxglove bloom from seed? Most foxglove will not bloom the first year from seed, but it should bloom the second year. Some varieties will bloom if they are sown early indoors.
Can I grow foxgloves in a container? These are fairly large plants and we do not recommend them for containers.
Are foxgloves deer resistant? Yes they are because they are toxic.