Tiarella cordifolia Appalachian Trail

Tiarella cordifolia 'Appalachian Trail' is a recent introduction with particularly colourful foliage and endowed with good longevity. This surprising variety shows red wine veins and spots that turn chocolate over the seasons, on a green lamina. From late May to August, feathery spikes of white flowers rise above the vegetation, creating a beautiful contrast of colours. This lively rhizomatous perennial, often semi-evergreen, quickly and effectively covers the soil in damp shade. Its trailing nature also allows it to be placed in a hanging basket, where it will enthusiastically overflow.

Tiarell 'Appalachian Trail' belongs to the Saxifragaceae family. It is a cousin of Heucheras with which it hybridises very easily. It is native to North American woodlands. It will reach an adult size of 10 cm (4in) for the foliage, 25 to 30 cm (10 to 12in) in flower, with a spread of 30 to 50 cm (12 to 20in). This Tiarella forms a spreading clump that spreads laterally through stoloniferous stems rooting at the periphery of the mother plant. Its semi-evergreen foliage is its first asset. Its dentate, heart-shaped and rounded leaves resemble those of Heucheras. They measure 10 cm (4in) in length and are beautifully crinkled, showing purple-wine spots radiating from the veins. This colour darkens over time, becoming chocolate brown on a green background. In May, individual white flowers appear, densely arranged in 'brushes' on stems about 30 cm (12in) high. The flowering, particularly long for the species, persists from mid-spring to August. The contrast of colour between the white inflorescences and the green, chocolate-spotted foliage is particularly attractive in summer.

In the wild, Tiarella cordifolia is generally found in wooded or mountainous environments. The 'Appalachian Trail' cultivar will naturally find its place in moist undergrowth, in the company of ferns, Impatiens balfouri, Solomon's seals, and astilbes. It can also be used as a waterside plant. It will also thrive in containers or shaded garden beds. It should be planted in a well-drained potting mix without excessive fertiliser, with watering carefully monitored in summer and reduced in winter.  Pots will need protection from cold winter winds.

Flower buds are formed during the summer, but they will only develop and bloom after being exposed to a minimum of 10 weeks of cold temperatures the following year. Cold is therefore necessary for the maturation of this perennial.