Heather GardeningBy careful planning, a new heather garden can give a colourful display in 3 to 4 years, which will require little maintenance and will last 15 to 25 years. Heathers are best planted in beds totally devoted to themselves, except for the addition of a few conifers or small evergreen shrubs to provide contrast in height and form.
A heather bed should be positioned in full sun, away from deciduous trees, and if possible, sited so that the main view is from the south, as foliage heathers always colour better on their southern side.
On heavy clay soils, break up any panned subsoils and incorporate generous amounts of well soaked organic soil conditioner. Sand, pea grit, or perlite can also be added to improve soil texture but avoid the use of sedge peat or spent mushroom compost as these can be too alkaline.
Estimate the planting area in square metres, deducting one square metre for each conifer or shrub included. Then multiply by five to obtain the number of heathers required.
Use no more than one conifer or shrub per five square metres and use those attaining a height of one to three metres in ten years. Plan to use about ten different heather varieties but reduce this number if necessary to ensure that the minimum number of plants of a particular cultivar is three.
Choice of species for various soil types
Some species of heather require acid soil conditions to thrive, whereas others
will grow in most soils.
The unique colour coded Kingfisher Nursery labels and posters will help identify the best varieties for the type of soil available.
The degree of alkalinity or acidity of your soil is measured on a scale of 0 to 14 known as the pH scale. Very acidic soil has a pH scale of 3.5, very alkaline soil has a pH just over 8. Ericaceous plants require significant quantities of iron, which in soils with a pH above 6.5 is rendered virtually insoluble and hence iron deficiency sets in, causing the plant to yellow and then die.
If you do not know your soil pH, purchase a soil testing kit, available at all good Garden Centres.
For soils with a pH greater than 6.5, the best advice is to restrict your choice to Erica carnea, Erica x darleyensis, Erica erigena, Erica manipuliflora, Erica vagans and any of the tree heaths with the exception of Erica arborea.Plant heathers deeply with the lower foliage resting on the soil surface.
Keep the bed free of weeds, a bark mulch will assist this task. Heathers benefit from an annual pruning and the following schedule may be of assistance.
- Calluna vulgaris - February or March, prune long flowering spikes back
to plant. Trim off all flower heads.
- Daboecia cantabrica - February or March, trim off dead flowers and
seed pods, to make bushy growth.
- Erica carnea - Every other April or May, trim flower heads with shears.
Trim the more vigorous cultivars hard to stop the centre going bare.
- Erica ciliaris - April or May, trim off dead flowers.
- Erica cinerea - February or March, trim off dead flowers particularly
long flowering spikes.
- Erica tetralix, Erica x stuartii - April or May, trim off dead
- Erica arborea, Erica australis, Erica erigena, Erica scoparia, Erica terminalis,
Erica x veitchii - After flowering, trim half of previous year's growth for
the first four years to encourage bushy growth; trim off broken branches. Stake
- Erica x darleyensis, Erica x oldenburgensis - Trim each June.
Do not be afraid of limiting growth.
- Erica manipuliflora, Erica x griffithsii, Erica multiflora, Erica vagans
- Leave flower heads on for russet colours during winter. Trim every March. Do
not be afraid of limiting growth.
- Erica spiculifolia - February or March, trim off dead flowers.
- Erica x watsonii, Erica x williamsii - Trim hard, every other
year in March.
In general, trimming retards the flowering by two to three weeks