University of Vermont Extension
Department of Plant and Soil Science
Leonard Perry, Extension Professor
University of Vermont
Meadow rues are a group
of easy-care perennials, growing in various habitats from sun to shade. With a diversity of flowers, leaves, and
growth habits, they offer lots of options in many gardens.
Although there are at least 130 species of this
perennial known in the world, only about a dozen and a half and their cultivars
are more commonly found for sale. These
were evaluated by Richard Hawke in trials at the Chicago Botanic Garden
recently, with a wealth of comparative information and the following
suggestions for the best selections.
Even though this site is in USDA zone 5b (-10 to -15 degrees F in
winter), most species that were hardy there also are hardy in much colder zones
such as in northern Vermont. Meadow rues are native to northern temperate
zones of the world, with some native to Siberia and the Far
The meadow rue genus (Thalictrum)
is in the buttercup family, as are its relatives the
columbine, delphinium, and hellebore.
Some form clumps, others spread by underground stems called
rhizomes. They range from six inches to
over 10 feet tall. The fine-textured
leaves are feather-like, or fern-like divided into groups of
three. Perhaps the most interesting part of their
botany is their showy flowers, which lack petals. Some species
have flower parts called sepals that resemble petals, others just have
a dense group of the stamens—the
male flower parts—that provide the show.
Depending on the species, flowers may be in bloom from late spring to
Meadow rues prefer moist, organic and well-drained
soils. The columbine meadow rue (T. aquilegifolium), named from the fact
the leaves resemble columbine (Aquilegia),
needs consistent moisture especially if in full sun. Most meadow rues in the Chicago trials, in a clay loam soil, grew
best in full sun even though they are often recommended for part shade sites.
Meadow rues don’t require much fertility, that from
organic fertilizer or compost often sufficient.
They don’t require much care, and are generally pest free. Some species may get powdery mildew and leaf
miners. If a plant becomes ragged after
bloom, it can often be pruned to the ground to encourage new growth.
The first to bloom of the best selections in the Chicago trials was the
columbine meadow rue already mentioned, which bloomed mid-May to
mid-June. The most common cultivar (cultivated
variety) of this species, and the one that was more robust with more
was ‘Purpureum’. It has blue-green
leaves, grows about four feet tall, and has an inflorescence (group of
up to six inches across. Individual
flowers are up to an inch across, lavender, and resemble pompoms.
They have no sepals, only stamens. Also as noted already, this
more moisture than most others, and may get some powdery mildew.
Many meadow rues bloom in mid-summer. The yellow meadow rue (T. flavum ssp.glaucum) and the cultivar ‘Illuminator’ both rated more highly than the cultivar
‘True Blue’. The former has blue green
leaves, reaches about six feet high, and has yellow flowers of only stamens in
July. This plant can spread by
rhizomatous stems, forming not a thicket but rather groups of distinct
plants. ‘Illuminator’ is similar only shorter
(four feet), and leaves emerge yellow in spring, later turning blue-green.
Another tall, mid-summer
meadow rue with yellow flowers (T. lucidum) is different from the others,
having linear leaflets emerging purple, then turning green. The clusters of pale yellow flowers can reach
nine inches across. The lesser meadow
rue (T. minus ‘Adiantifolium’) has
leaves resembling the maidenhair fern (Adiantum). Reaching about five feet high, the yellow
flowers are small and in more open inflorescences, so impart a fine
texture. Its leaves emerge bronze, then
The tall meadow rue (T. pubescens) is a different one for
mid-summer bloom, having creamy white flowers composed only of stamens, and
reaching up to 10 feet tall. On the
other extreme is the Kyushu meadow rue (T. kiusianum), only reaching about six
inches tall. It too blooms in
mid-summer, only with pink flowers composed of stamens. It performed better in trials than another
dwarf species (T. ichangense).
Blooming from mid-summer
to early fall is the lavender mist meadow rue (T. rochebruneanum). Unlike
most other meadow rues, this one has prominent lavender sepals in the flowers
surrounding the yellow stamens. This
species and cultivars reach about six feet high, and with an open habit have a
“see through” quality. In the Chicago trials there were
no differences among the species and cultivars ‘Lavender Mist’ or ‘Purple
Mist’. The cultivars often had minor
powdery mildew, not seen on the species.
Blooming from mid to
late summer is the cultivar ‘Elin’, supposedly a hybrid of the lavender mist and the yellow meadow rues.
Although the flowering was similar to the lavender mist, it bloomed a
couple weeks earlier. It was more
vigorous than either parent, reaching eight feet high. It did not drop leaves and thin out later in
the season, as lavender mist tends to.
It can get powdery mildew, and slight leaf miner damage.
Whether for part shade or full sun, consider the
taller meadow rues for backs of borders or centers of island beds. The medium height species might be placed in
small groups throughout beds. Of course
the dwarf species can be massed along the fronts of beds, or grown in raised
gardens and rock gardens where they can be seen better.
The fine-textured meadow rues can be combined with
the coarse-textured rodgersias (Rodgersia)
and ligularias (Ligularia) for
dramatic contrast. In full sun, try them
with daylilies (Hemerocallis), garden
phlox (Phlox paniculata), and
ornamental grasses. In part shade, try
them with turtleheads (Chelone) and
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