The Heather Garden

This area forms a fine transition towards the collection from the Southern Hemisphere.

The heather family has a centre of diversity in South Africa, where the genus Erica has more than 700 species. Unfortunately, none of these can be expected to survive at Milde without being brought indoors for winter.

But others have survived, including a single shrub of Epacris paludosa from Mt Kosciuszko in south-eastern Australia. There are also wild-collected species of Gaultheria from Chile, such as the small G. pumila.

In addition to the heather family, there are some heat-loving species with the same growth form. Examples are Podocarpus (Podocarpaceae; a conifer) from the South Island of New Zealand, Maytenus disticha (Celastraceae) and Myrteola nummularia (Myrtaceae) from Chile, which are likewise adapted to heathland in the mountains of the Southern Hemisphere.

'Flowering heathers' is the theme on the left side of the path up through the Heather Garden. The aim here is to show heathers with rich and beautiful flowering, especially from the genus Erica, of which there is a large selection of cultivars. The theme is spread across four beds, which have been given their own names on the map.

• Winter heath (Erica carnea) comes into flower first. It is the hardiest species, and is therefore planted down towards the car park, where it is coldest in winter. It comes from mountain areas in Central and South-Eastern Europe, where it flowers just after the snow has gone. In our mild coastal climate, it is tempted into flower early – the earliest cultivars appear as soon as December and January, and continue right through to the end of May.
• Summer heath is the bed above, where a range of cultivars of different heather species are planted. St Dabeoc's heath (Daboëcia) comes first, in late June, and is soon followed by several species and garden hybrids of Erica. We struggle to find heathers that can fill the gap in flowering from May to June, but have planted some Rhododendron that flower at this time. It has also proved difficult to find species hardy enough for our climate. For example, only 19 of the 69 accessions of Daboëcia we have planted out are still alive. Most of the cultivars have been short-lived, but a plant collected in Spain is still going strong, and the occasional self-sown seedling may prove to be hardier.
• Cross-leaved heath and friends shows cultivars of cross-leaved heath (Erica tetralix) and some hybrids in which cross-leaved heath is one of the parent species. Cross-leaved heath is a hardy species common in our region, but it has not been the easiest to establish in the garden. Of the 55 accessions we have tested, only 13 are still alive. We are searching for colour variants in our local nature, and have collected some plants locally around Bergen. Four of these are alive.
• Bell heather (Erica cinerea) dislikes winter frost and grows wild only right along the outer coast of Western Norway. A few have nevertheless proved hardy enough to thrive in the most sheltered spots in the garden. Only nine of the 94 accessions we have tested are still alive; one is a seedling that has come up in the garden, three were collected in the wild in Western Norway, and the rest are garden cultivars.

Here we present heathers with a wide range of colours and variation throughout the year, but the flowering continues on from theme 2 and extends through most of the autumn. In the Patchwork Quilt, cultivars of Calluna vulgaris (heather, or ling) dominate. Since heather typically flowers in autumn, it has become common to call it 'autumn heather', a usage we hope to stop, since that name properly belongs to Erica vagans.

The Patchwork Quilt also contains several sub-beds:

• The colourful ones consist of a collection of heather with a wide range of colours in foliage and branches. 
• The faithful ones are a collection of the most reliable cultivars for Norwegian conditions. 
• The Patchwork Quilt is also the name we give to the largest and richest bed of heather. This large bed presents a rich variety of flower colours, flower forms such as double or bud-flowering types, foliage colour and growth forms.

At the edge of the pine forest, the local climate is ideal. The sun provides warmth even on a winter's day, and the tall tree canopies reflect heat radiation on winter nights, so the frost doesn't become too severe. Here we show a mixed company of larger shrubs and small trees that thrive in peaty and woodland soil and have high demands on their growing site, e.g. pieris (Pieris) in the heather family, sweet pepperbush (Clethra) in the Clethraceae, and camellia (Camellia) in the tea family.

Heathers are not usually associated with lime, but there are exceptions. Using light red marble from Moster in Sunnhordland and plenty of marl, we have created a limestone outcrop where we trial heathers that thrive on calcareous soil. One such plant is Arctic bell-heather (Cassiope tetragona), an Arctic-alpine species found in the mountains of northern Norway. Even so, it thrives here, alongside other Cassiope species. Together with these, we have also planted mountain avens (Dryas octopetala) of the rose family, which grows alongside Arctic bell-heather in Northern Norway. We are trying to establish Lapland rosebay (Rhododendron lapponicum) alongside them, but have not succeeded with this – yet.

It is a common belief that heathers need it wet and acidic. The truth is that most do not like standing in water, but thrive in a damp climate with rainfall throughout the year.

On the mound at the top of the Heather Garden, we have planted various low shrubs that grow on peat soil. Here, among others, bog rosemary (Andromeda), Kalmia and Zenobia flower. A biogeographical surprise is leatherleaf (Chamaedaphne calyculata), which in Scandinavia is found only in the far north-east of Finland, where it is a bog plant. Here it has thrived for many years without problems, even though it has been claimed that it cannot grow in the mild coastal climate of Western Norway.