Dig it – November's tips from the Secret Gardener

Small Tortoiseshell on Heather

Evergreen heathers are a great way to bring colour into the garden in winter. These small bushes, characteristic of heaths and moors, have wiry stems with tiny leaves and flowers ranging from white through to pink, purple and crimson. The foliage colour is also variable with cultivars having shades of green, bronze, gold, silver or yellow. Popular heathers grown in the garden are varieties of either Calluna, Erica or Daboecia.

1.    Heather (or Ling) Calluna vulgaris

Calluna is found throughout Europe. It is a very hardy plant and carpets heathlands and moorlands with pink flowers from late summer to early autumn. There is only one species but a multitude of varieties, with heights varying from 5 to 50cm. There are no mid-winter or spring-flowering varieties of Calluna and none of them can tolerate lime.

Naturally occurring variations where plants remain in bud formation have been harnessed by breeders to produce numerous forms (usually marketed under the brand name of ‘Garden Girls’ or ‘Beauty Ladies’). As the flowers do not open and cannot be pollinated, they retain their colour for an extended period. Pollinators such as bees, moths and butterflies cannot access nectar in the flowers so they hold little value for wildlife.

2.    Heath Erica

Erica can be a more versatile plant than Calluna as there is no standard flowering period – by choosing a range of varieties you could have a bed in bloom all year round. Additionally, there are lime-tolerant as well as lime-hating species.

Lime-hating species which are native to the UK:

Bell Heather E. cinerea (flowers Jul to Sep, height 15-30cm) is found growing on dry heathlands alongside C. vulgaris.

Cross-leaved Heath E. tetralix (flowers Jun to Oct) is very hardy and is common on wet heaths and moors throughout the UK.

Dorset Heath E. ciliaris (flowers Jul to Oct, height 30-45cm) is large-flowered and naturally occurs on damp heaths but will survive in a garden.

Cornish Heath E. vagans (flowers Jul to Oct) mainly occurs as a native on the Lizard Peninsula in Cornwall.

Lime-tolerant species:

Winter Heath Erica carnea (flowers Jan to Apr) is low growing, with a spreading habit useful for ground cover and suppressing weeds.

Irish Heath E. erigena (flowers Mar to May) grows up to 120cm so can be used as a low hedge.

Corsican Heath E. terminalis (flowers Jul to Dec) is a tall, bushy variety that grows to 1m.

Darley Dale Heath E. x darleyensis (flowers Nov to May) is a cross between E. carnea and E. erigena and makes a small bush of 45cm high.

3.    St Dabeoc’s Heath Daboecia cantabrica

Daboecia can be found growing naturally in western Ireland. Its bell-like flowers (Jun to Oct) are larger than those of Calluna. It will grow to a height of 30-35cm and requires acid soil conditions. 

Planting

Heathers grow best in an open sunny situation in well-drained soil. The winter/spring flowering heathers will tolerate some shade but won’t flower as well. Golden foliaged varieties also need full sun to maintain their bright colours.

If you have acid soil you can grow most of the heathers. If your soil is neutral or alkaline (pH above 6.5) then you will need to grow the lime-hating varieties in containers with ericaceous compost. Ensure the plants are kept moist during the first year of planting and in dry conditions. For best results feed sparingly in spring and early summer with a general fertiliser.

Trim to the base of the flowering spike after flowering to keep plants compact and bushy.

Butterflies and moths

Painted Lady on HeatherAs heathers are such widespread native plants in the British Isles, it is not surprising that hundreds of insect species, including butterflies and moths, are known to feed on them as larvae or take their nectar. On heaths in lowland Britain a characteristic butterfly is Silver-studded Blue, which will nectar on E. cinerea. Its caterpillars use C. vulgaris as a foodplant, as part of a complex life cycle including black ants. Other butterflies found on heathland are Grayling, Small Heath, Green Hairstreak, Gatekeeper, Common Blue and Small Copper. On Scottish moorland Green Hairstreak caterpillars can feed on heather and in wetter, boggy areas the Large Heath butterfly will nectar on E. tetralix. However, in your garden you are more likely to attract Small Tortoiseshell and Painted Lady to nectar on the flowers.

There are several moths that are fairly common across the UK and can be found on heathland, moorland and possibly in gardens. 

Beautiful Yellow Underwing caterpillar

Narrow-winged Pug caterpillars feed on Calluna flowers. True Lover's Knot caterpillars feed on Calluna and Erica as do those of the well-camouflaged caterpillars of Beautiful Yellow Underwing, which is a swift, day-flying species that also nectars on heather. Other more generalist moths will feed on a range of plants and bushes, which can include heathers – for example caterpillars of Double-striped Pug, Knot Grass, Broom Moth, Common Marbled Carpet and Dark Marbled Carpet. If you have planted a reasonable amount of heather and your garden is near heathland or moorland then some of these moths could potentially visit.

White heather is regarded in Scotland as being lucky and sprigs of it are often sold as a charm and worked into bridal bouquets or used on celebration cakes. Let’s hope the heather brings luck in attracting butterflies and moths to your garden.

Happy Gardening!

The Secret Gardener

 

For more information visit:

www.heathersociety.org

www.theheathergarden.co.uk