American alumroot – planting, care and tips

American alumroot (Heuchera americana)
American alumroot (Heuchera americana) - by Andy Mabbett

Thanks to its evergreen leaves, American alumroot has a high ornamental value throughout the season. It becomes a real eye-catcher in late spring when it opens its cloud-like flowers.

Profile of American alumroot:

Scientific name: Heuchera americana

Plant family: saxifrage family (Saxifragaceae)

Other names: common alumroot /

Planting time: spring or autumn

Flowering period: May to June

Location: partially shaded to shady

Soil quality: sandy to loamy, humus rich

These information are for temperate climate!

Use in: group planting, planters, underplanting, natural garden, potted garden, forest garden

Winter hardiness: hardy, USDA Plant Hardiness Zones: 5 (-26 °C / -15 °F)

Bee and insect friendly: Yes

Plant characteristics and classification of American alumroot

Plant order, origin and occurrence of American alumroot

The American alumroot (Heuchera americana) is, as its botanical name suggests, native to the USA and Canada. There the perennial prefers to grow in crevices and protrusions on cliffs and forests on humus-rich grounds. It belongs to the saxifrage family (Saxifragaceae) and is one of the parent species for the large number of cultivated Heuchera species. It is not always easy to get the pure type in stores.

Characteristics of American alumroot


Heuchera americana grows in compact clusters with 50 to 100 centimeter (20 to 40 in) high flower stems. The evergreen perennial forms short runners with which it slowly but steadily grows in width.


The young leaves of American alumroot are reddish in color when they shoot, but then turn green relatively quickly. They are rounded and slightly lobed in outline. The varieties, of which the American alumroot was involved in cultivation, often have silver-tinged leaves.


In May and June, the tall, upright, branched flower panicles of American alumroot emerge from the leaf cluster. They abundantly bear the delicate bell-shaped flowers, which are greenish-white in color.


Small capsule fruits develop towards late summer.

American alumroot – cultivation and care


American alumroot is planted best in partially shaded to shady places. It does not tolerate direct sun well and the blossom suffers in deep shade. A sheltered location is recommended so that strong cold frosts do not cause any damage in winter.


In nature, American alumroot thrives on permanently fresh or damp soils, where water can seep away easily. Accordingly, the garden soil should be fresh and at the same time permeable. The ornamental plant does not like waterlogging at all. Well drained and humus clay soils are ideal. In terms of pH, the American alumroot is tolerant, but slightly acidic soils are preferred.


Like most perennials, American alumroot is best planted in spring or autumn. Put it a little deeper than it was in the pot it was planted in when you bought it, because it shows a tendency that its root ball pushes out of the ground over time. A planting distance of 40 centimeters (16 in) is recommended, which corresponds to about six plants per square meter (10 sq ft).

Care / Watering / Fertilization

If the drought persists, you should make sure that the soil does not dry out completely and water it deeply if necessary. It makes sense to remove the old leaves in good time before the new shoots in spring. A little compost in the spring will stimulate growth.


Like all alumroots, Heuchera americana should be dug out of the ground every three to four years and the root ball should be divided. This preserves the vitality of the perennial. The best time to do this is after flowering until autumn.


Heuchera americana is best propagated vegetative by division after flowering or by cuttings in spring.

Diseases and pests

Root rot is always an indication of waterlogging. Occasionally the black weevil and especially its larvae can be a nuisance.


American alumroot is hardy down to -26 °C / -15 °F. In rough, snow-free winters, it is advisable to protect the clusters with brushwood covers against freezing temperatures. Please make sure that the soil does not dry out even during the cold winter weeks.

Use in the garden

In contrast to the often spectacular leaf coloration of the Heuchera hybrids, American alumroot is rather modest. In order to increase the effectiveness of the wild perennial, it is best to plant them in larger groups in near-natural garden areas. Suitable partners are foamflower, astilbe, Alpine barrenwort, ferns and forest grasses. The year-round attractive American alumroot is also a good choice for planters in partially shaded places.


  • Heuchera americana ‘Cassian’ is also known as the silver-leaf alumroot because its green leaves are covered with silver with the dark leaf veins. Like the species, the flowers are greenish-white
  • With ‘Chocolate Veil’, the leaves have a red-brown basic color, are also darkly veined and overflowed with silver. Its flowers are greenish white
  • The variety ‘Ruby Veil’, the white flowers sit on red-brown stems and are accompanied by purple-red leaves with fields overflowing with silver
  • ‘Velvet Night’ has white flowers and red-brown leaves with dark leaf veins and a silvery hint

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