Gardeners invariably think of thalictrums, or meadow rues, as tall, airy plants with ferny foliage and slender stems topped by mauve flowers. A herbaceous perennial, thalictrums take their name from Thalia, one of the Greek muses, and often exude a delicate, willowy charm that few of us can resist. Thalictrums have much to offer as garden plants and many have the rare qualities of a delicate, understated elegance and an strong architectural presence. Here Val Bourne recommends 16 of the best.
Thalictrum delavayi ‘Ankum’
Come July, this very select, airy form produces generous sprays of pale-lilac ‘petals’ surrounding sulphur-yellow stamens. A selection made by Coen Jansen and named for his nursery in Ankummer, in the Netherlands.
Height 2m. Hardiness rating USDA 5a.
T. delavayi var. decorum
Long, dark, wiry stems hold small, delicate, three-lobed, green leaves topped by relatively large, bluish-purple flowers, each with four pointed ‘petals’ set around a boss of golden stamens.
Height 1m. Hardiness rating USDA 5b-8b.
Slender and upright with stiff, ridged, green stems and unusual shiny, green, herringbone-shaped foliage. The fragrant, wispy, lemon flowers appear in July, by which time the leaves will have yellowed.
Height 2-3m. Hardiness rating USDA 7a-9b.
T. Splendide White (= ‘Fr21034’)
Selected by French breeder Thierry Delabroye from a cross between T. delavayi and T. elegans, this produces a profusion of sparkling white flowers on elegant stems above aquilegia-like foliage.
Height 2m. Hardiness rating USDA 4a-7b.
T. delavayi var. mucronatum
Very similar to T. delavayi var. decorum, but is often taller and perhaps with a definite point to the end of each petal. The pretty, bell-shaped flowers are lilac-pink with primrose stamens. Stood out on the trial.
A dainty Chinese thalictrum with black, wiry stems and dark buds held above tiny, blue-green leaves. Flowers are large, lavender orbs of stamens and last a very long time. Only available at Crûg Farm Plants.
T. flavum subsp. glaucum
Grown for its handsome powdery, blue-grey foliage, strong upright stems and frothy, yellow flowers. Foliage emerges pale-yellow and is often used with dark tulips. Height 1.5m. Hardiness rating RHS H7, USDA 5a-9b.
A small, slow-growing Asian species with huge potential if it proves reliable over winter. The plum-leaved forms have miniature begonia-like foliage. Several duskier forms are being micropropagated.
Height 5cm. Hardiness rating USDA 6a-9b.
A star performer with dramatic, architectural stems that are thinner and blacker than those of ‘Elin’ (below left) but still self-supporting. Pretty, blue-green foliage and pink buds that mature to white, but ordinary flowers.
Tall, strong, damson-toned stems, purple-flushed grey-blue foliage and delicate purple and cream flowers. At Great Dixter in East Sussex it’s used with the purple Tulipa ‘Shirley’ to great effect.
Height 2.5m. Hardiness rating USDA 5a-9b.
T. minus ‘Adiantifolium’
Small and low growing with delicate foliage, similar to a maidenhair fern, which lasts well all season. A perfect foliage plant for quiet, shady areas. Clump forming and non-invasive. Insignificant yellowish flowers.
T. ‘Tukker Princess’
A giant form with stems striped in pink, dusky-grey and lime-green – reminiscent of a pair of grandad’s well-washed pyjamas. Large soft-yellow flowers contrast with the glaucous, ferny foliage that lasts until November. Spectacular.
Thalictrums with colourful stems are extremely useful in modern prairie-planting schemes that involve statuesque, late-flowering perennials and grasses. This is because thalictrums are out of the ground by March and by mid-April they’re 30cm high while the rest of the border is generally still underground. The nre growth emerges like strong asparagus spears, then leafs into purple-flushed growth. This doesn’t get eaten by slugs, or suffer from frost damage, so is often used as a backbone in continental planting. April-flowering tulips work well with young thalictrum foliage and you can create a beautiful blend with the dusky Triumph tulips ‘Shirley’ and ‘Negrita’, or set off an ivory-cream Darwin tulip, such as ‘Floradale’.
Where to see
Tel 01558 668998
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Where to buy
For more information on hardiness ratings, click here.
Writer Val Bourne