Sunday, June 20, 2010

The Foxglove

The Foxglove, Digitalis purpurea is a large, showy plant — a striking addition to any shade garden. They look best grouped toward the back of a bed, where their blossoms will brighten an otherwise gloomy spot. Flowers in shades of white, yellow, pink, rose, lavender and purple grow on spikes that vary in height depending on the variety.

The Foxglove is a wonderful, statuesque plant; much appreciated in cottage garden situations, where their elegant stance towering above the range of annuals, biennials and perennials adds beauty and height to the rich pattern of the garden. These tall erect plants, bearing long tubular flowers are certainly well worth growing.

On the inside of each flower, conspicuous spots of crimson, burgundy or chocolate, are scattered in the throat. In all cases the individual flowers are about the size and shape of a thimble. The origin of the botanical name, Digitalis, is based upon the Latin word digitatus for finger. Perhaps this is because the thimble-like blooms fit a human finger in the way a thimble does.

Digitalis purpurea is a biennial, seeding freely when happy. Since it does not produce flowers (nor, therefore, seeds) until its second year, you must plant them two years running to have Foxgloves every summer.

Seeds can lie dormant for years if conditions are unfavourable — if there is inadequate light or moisture.

Most Foxgloves thrive in light shade. D. purpurea loves to be cool, but Mediterranean species need sun. Although foxgloves prefer lighter soils, they can survive on heavy clay with the addition of good compost to the top 10cm of soil. The fibrous roots spread out making vast mats to support the flower spikes, so mulch well to retain moisture.

If you are collecting your own seed, sow immediately when fresh — and thinly, as overcrowded seedlings are prone to fungal diseases. It thrives best in dappled shade and is perfectly adapted to cope in sites where light varies throughout the day.

It is an invaluable asset where gardens are separated from each other by hedges, fences or walls — perimeters are the most awkward areas of the garden but exactly the sort of site this plant would choose for itself.

For readers in the USA: Foxgloves thrive in Zones 4-10, except in Florida and along the Gulf Coast.


Digitalis purpurea

This is the only true British native and is also the biggest and most impressive foxglove, sometimes reaching 1.8m high. It has soft, downy leaves and a strong stem that can carry hundreds of tubular flowers. The buds are white, whilst the flowers are a pinky-purple with dramatic speckles and clusters of short hairs in the throat. A biennial or at best a short-lived perennial, it is best to grow annually. Foxgloves self-seed readily, so an annual show of these impressive flowers is easy to achieve.

Digitalis purpurea excelsior

Within the excelsior group, there is a wide range of pastel-coloured flowers. The flowers grow all around the stem and come in a variety of colours. The compact group of the Foxy Group rarely exceeds 75cm high. There is a wild sub-species of Digitalis purpurea, heywoodii which has silvery leaves and pale ivory flowers. Digitalis purpurea Giant Spotted Group is incredibly eye-catching because of the large patches of dark purple in the flowers’ throats. All are best grown annually.

Digitalis grandiflora

This plant closely resembles Digitalis purpurea. It has deep cream-coloured flowers whose throats are streaked with distinctive rusty markings. It can also have bright yellow flowers and appears in the early summer. Again this is a biennial or short-lived perennial.

Digitalis laevigata

This plant is great in midsummer as it produces spires of brownish-yellow flowers with a white lower lip and speckled interior. It is more of a perennial than other species, but again it is worth collecting seed and cultivating.

Digitalis lutea

This is a beautiful foxglove with slender stems of pale yellow flowers, which start in early summer though are sadly relatively short lived. Perennial.

Digitalis x mertonensis

Quite understandably a very popular foxglove with its large dusky pink flowers, though the stems are slightly shorter than those of Digitalis purpurea. Despite it being a hybrid, it still produces parent replicating seed. It is widely appreciated as a colourful perennial.

Digitalis parviflora

A great foxglove for the early summer, with dark orange-brown densely packed flowers along the whole length of the flower spike. Perennial.


Foxgloves like to grow in a soil that is both moist and rich, ideally with a pH of 6 to 7.5. If you prefer to start growing foxglove seedlings indoors first then they should be prepared about ten weeks before they are due to be transplanted into the garden in late autumn, a few weeks before the first frost of winter. Members of Digitalis usually take about two or three weeks to germinate at 15 to 18oC.

If sowing directly into the garden, plant foxglove seeds toward the rear of your flower bed, since the plants grow quite tall. They do best in partial shade as long as they get regular water during dry periods in summer. Clear the area that you will be planting of leaves and debris and rough up the soil with the hand rake to a depth of about 3cm.

Space out the seeds so that they aren’t planted too closely. The seeds are tiny, and you should try to plant no more than one or two seeds in a 7,5cm area. This will give you a dense growth of seedlings. When they have grown about 5cm tall you should thin them out to one plant per 20cm to 30cm. Transplant the seedlings that you take out to other locations if desired.

Cover the seeds with soil and press down the soil so that the seeds have good contact. Water the area. Keep the soil damp for proper germination but don’t over water because it could make the seeds rot.

Saving seeds is an easy process of waiting until the bloom has gone and the seed pod turns brown. Save these seeds and plant elsewhere or let the plant regenerate itself. To have plants in the same area year after year, let the seeds fall where they may.

Foxglove a distinctive plant to use as a backdrop for other flowers, among flowering shrubs, or as elegant specimen plants in the summer garden.

In flower borders, plant Foxgloves in the back of the bed with Shasta Daisies or Peonies in the foreground. Perennials that have round flower heads provide good contrast to Foxglove’s vertical lines.

In naturalistic settings, Foxglove is right at home, able to thrive at the base of old stumps and rotting logs. Planted with Ferns along a woodland walk, Foxglove will reseed and bloom in colourful colonies for years.

The best companions for Foxglove are flowers and plants that complement its tall, narrow form and dramatic blooms.

Combine classic cut flowers, such as Sweet William, Snapdragons and Roses, with the strawberry-pink Merton Foxglove.

Summer-blooming annuals, such as Petunias, Geraniums and Alyssum, thrive in the same soil and share the same bloom time as Foxgloves. Combine bright annuals to vibrate against the white blooms of the Foxglove Alba.

Adding a general purpose fertiliser once a month will result in bigger, fuller blooms. Apply a thin layer of compost each spring, followed by a 5cm layer of mulch to retain moisture and control weeds.

Stake tall varieties to keep them upright. Remove the central flower spike after flowering to encourage other side shoots to form and produce more flowers.


There are few insect and disease problems. If problems occur, treat early with organic or chemical insect repellents and fungicide.


The leaves are toxic. If you have young children or pets, you might want to steer clear of this flower. The poisonous substance in the leaves is called Digitalis. You may recognize this as a chemical sometimes used in the treatment of heart disease.

Very hardy thanks to:

Gardening Made Easy

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