Cultivation

Sanguisorbas are easy to propagate by seed, although often erratic to germinate, but they are highly promiscuous and seedlings are likely to be hybrids. Interesting progeny may be produced but can exhibit huge variation. There is also a distinct possibility that seedlings may germinate within a named clump and compromise the original plant if they are more vigorous. This has happened several times with Sanguisorba ‘Tanna’, which is a diminutive floriferous form that should be no taller than 30cm. Many plants offered as S. ‘Tanna’ are 60cm or more and are most likely to be hybrids. Cutting off the spent flowers is one way of avoiding this but denies insects and birds nutritious seed.

Increasing a clump of a named sanguisorba involves division, most successful in spring when plants are growing away quickly. They have a rhizomatous rootstock and pieces should have a shoot and piece of root attached. A clump can be divided into larger pieces and replanted where required making sure to water in well. Use a sharp kitchen knife to divide plants rather than back to back garden forks, which damage the plant.

In general, sanguisorbas do not suffer greatly from pests and diseases. Like strawberries, they are members of the rose family, and so are susceptible to vine weevils, which burrow into the rhizomes. However, this does not normally cause too much of a problem in a garden situation but is more severe with plants in pots. Black spot is occasionally a problem on some hybrids and powdery mildew can take hold in dry conditions. If mildew is spotted early enough a good soaking with a seaweed feed can prevent further spread as can a dose of an environmentally friendly foliar feed and pesticide, such as SB Plant Invigorator. Deer and rabbits are particularly fond of eating sanguisorbas.

The different shapes and forms of sanguisorba inflorescences work well in meadow and naturalistic plantings as well as in herbaceous borders. Tall grasses and perennials are enhanced by spots of colour that appear to hover around them on the wiry stems of the sanguisorbas. One nurseryman has described Sanguisorba officinalis ‘Arnhem’ as ‘like a swarm of small raspberries’. The colourful dangling caterpillars of Sanguisorba hakusanensis, Sanguisorba hakusanensis ‘Lilac Squirrel’, Sanguisorba ‘Pink Brushes’ and Sanguisorba ‘Candy Floss’ are certainly not subtle. In dry weather they look great; but in wet conditions can look a little bedraggled. Many sanguisorbas exhibit good autumn foliage tints.