Veronicastrum sibiricum Siberian culver's root
Symbivit Tric (arbuscular)
Symbivit (arbuscular)Veronicastrum
The genus Veronicastrum is a small group of perennial and fairly robust herbaceous plants comprising 5-6 species. They are known for their upright habit and whorled leaves that create a tiered silhouette reminiscent of certain shrubby species, often compared to chaste tree or hemp. The Czech Perennial Growers’ Association selected the genus Veronicastrum as Perennial of the Season in 2016. These plants grow in North America and eastern Asia, most commonly at woodland edges, in prairies and in moist meadows. In American tradition some species are known as Culver’s root, because early herbals mention a physician named Dr Culver who prepared a bitter tonic from their roots. The inflorescences consist of one terminal spike accompanied by several lateral ones, giving the plants a distinctive architecture and making them highly attractive to pollinating insects. The best-known and most widely grown species in gardens are the Siberian and the Virginian Veronicastrum, both named after their native regions.
Siberian culver’s root differs from its North-American brother with larger leaves and shorter stems – compact growth. Its leaves are wider and coarser, mid to deep green, and grow usually in whorls of 6. They may resemble cannabis. In early summer the tips of the stems begin producing flower buds composed in long spikes, botanically more correctly classified as terminal racemes, opening in early July into small, lavender blue to soft violet flowers with long tubes owing to which they look hairy.
Last update 25-01-2014
Veronicastrum are undemanding perennials that grow well in any ordinary garden soil with sufficient light and moisture. They thrive in full sun but tolerate light partial shade, although they may lean towards the light in part-shade. The ideal soil is moderately fertile, humus-rich and slightly moist; prolonged waterlogging does not suit them, but on the other hand they tolerate short dry spells and do not require frequent watering. In drier gardens it is helpful to add compost, mulch or water-retaining minerals to the soil to maintain moisture. After planting they root quickly and from the second year form full clumps. Feeding is not necessary, but poor soils benefit from a spring dose of compost or a light application of organic fertiliser. The tallest cultivars sometimes need support to maintain a neat shape, even though their stems are firm, because the inflorescences can be heavy. After flowering the spikes can be removed to keep the border tidy, but it is not essential. All Veronicastrum are long-lived and after several years form broad clumps that can be divided easily in spring or autumn. They are not prone to diseases or pests and tolerate cold winters well, down to minus forty degrees Celsius. In autumn they can be cut back, but the dry stems can just as well be left over winter and removed in spring. All species and cultivars are attractive to insects, making them suitable for naturalistic and biodiversity-focused plantings.
