How to Grow and Care for Meadow Rue

Many species in the Thalictrum genus of plants are known by the common name meadow rue. Sizes vary radically from species to species, ranging from six inches to eight feet in height, but all these members of the Ranunculaceae (buttercup) family are clump-forming perennials that grow from rhizomatous roots, all with lacy, fine-textured foliage. The foliage is usually light green in color, though there are species with more chartreuse leaves.

The plant is often mistaken for columbine because its leaves and drooping flowers bear a resemblance to that plant. The flowers are small and can be yellow, white, lilac, or lavender, depending on the species. Although the point could be argued with some of the named cultivars, generally speaking, meadow rue flowers are small and relatively subtle. This is a plant that is usually chosen for the texture and color of its delicate foliage rather than for spectacular blossoms.

Typically planted in the spring as potted nursery plants, or in the fall if sowing seeds directly in the garden, meadow rue is relatively slow-growing for a wildflower, taking as long as three years to develop into a mature flowering plant. Potted nursery plants are generally a year old at the time of sale, and might not flower until a year after planting. Seeds can take longer.

Common Name	Meadow rue
Botanical Name	Thalictrum spp.
Family	Ranunculaceae
Plant Type	Herbaceous perennial
Mature Size	1–8 ft. tall, 1–5 ft. wide (varies by species)
Sun Exposure	Full sun to partial shade (varies by species) but most prefer partial shade
Soil Type	Well-drained, rich, humusy
Soil pH	Acidic to alkaline (5.0-8.0); varies by species
Bloom Time	Spring, summer (varies by species)
Flower Color	Light purple or pink, white, yellow (varies by species)
Hardiness Zones	USDA 3–7 (varies by species)
Native Area	Northern Hemisphere

Meadow Rue Care

Care requirements vary considerably depending on the species being grown, but most are relatively large, bushy plants that will do well in most soil types, though with a preference for rich, moist soil.

Any species more than five feet tall will probably need to be staked in order to keep it upright. A more holistic approach is to arrange in groups of three or more so the stems can support each other as they do in the wild. Most species grow two to four feet wide, so space them accordingly in your garden.

Meadow rue is much stronger than its delicate foliage and flowers would suggest. It is not troubled by any serious pest or disease issues. Most common is powdery mildew, which almost never causes serious problems. Slugs and snails might feed on the foliage.

Light

Sunlight requirements vary by species, but most types of meadow rue prefer part shade or dappled light conditions, though they will tolerate full sun. The need for shade is more pronounced near the southern end of the hardiness range. Some species will do well in nearly full shade.

Soil

Many species of meadow rue are native to moist woodlands and seasonal marshy areas, and when cultivated for garden use, they will grow best in rich, moisture-retentive soil. An average, medium-moisture, well-drained soil will do just fine, too, provided the plants are offered regular irrigation.

Water

For best results, keep meadow rue plants moist but not soggy. The plant is not prone to insect infestation or diseases, but it can develop fungal problems if it sits in standing water. If planted in typical well-draining garden soil, about one inch of water per week keeps it happy. If grown in full sun, it will require more water.

Temperature and Humidity

Most species of this perennial plant prefer the moderate climate of USDA cold hardiness zones 4 to 7, though some species do well as far north as zone 3 or as far south as zone 9. Generally, this plant does not like the hot and humid summers of the deep south. A thick mulch can help the plant at both climate extremes—cooling the soil in hot climates and providing winter protection in the far north.

Fertilizer

No feeding is recommended for these plants if the soil is suitably rich. In poor soils, a yearly application of balanced fertilizer might be helpful.

Types of Meadow Rue

Choosing a type of meadow rue is more about selecting one of the many species than choosing among named cultivars. In many cases, you will need to shop at specialty native plant nurseries or online retailers, as many of these species are not available at standard nurseries. Where named cultivars exist, they are usually the result of efforts to improve on native species by making the flowers more plentiful or colorful.

• Low meadow rue (T. minus) has greenish-yellow flowers on green/gray-green foliage. It grows 12 to 24 inches tall and is hardy in USDA zones 3 to 7.
• Kyoshu meadow rue (T. kiusianum) is a classic lavender variety native to Japan. It reaches a modest four to six inches in height and is hardy in zones 6 to 8.
• Columbine meadow rue (T. aquilegifolium) has mauve blooms. It grows two to three feet tall and is hardy in zones 5 to 7. 'Album' is a popular white-flowering cultivar. 'Black Stockings' is a variety with blue-purple flowers and black flower stalks.
• Yellow meadow rue (T. flavum) is native to Europe and the eastern Mediterranean. It grows three feet tall and is hardy in zones 5 to 8.
• Yunnan meadow rue (T. delavayi) is native to China. It grows up to five feet tall and is hardy in zones 4 to 7. 'Splendide' is a very popular hybrid cultivar with unusually profuse lavender-pink flowers on burgundy stems.
• Dusty meadow rue (T. speciosissimum) grows four to six feet tall, with buttery-yellow flowers that grow in dense clusters in summer. Native to Spain and Northwest Africa, it is more heat tolerant than other varieties.
• Lavender mist meadow rue (T. rochebrunianum) is native to Japan. The plant reaches an unusual height of 6 to 8 feet. It displays lots of lavender violet flowers with yellow stamens and is hardy in zones 4 to 7.
• Early meadow rue (A. dioicum) grows 8 to 30 inches tall and blooms with small whitish-green flowers in spring. It is hardy in zones 3 to 7.
• Tall meadow rue (A. pubescens) is another spring bloomer. It is a tall plant that can tower as tall as eight feet. It blooms in early summer with whitish-yellow flowers and is hardy in zones 3 to 7.

Pruning

Flower stems can be cut back after the blossoms fade to clean up the look of the plant and allow the foliage to take front stage. Deadheading might slightly extend the bloom period somewhat, but don't expect a months-long bloom period.

The plant can be cut back to ground level if it begins to turn yellow due to the heat of summer. This kind of pruning doesn't harm the plant; it will return with vigor the following year.

Propagating Meadow Rue

Meadow rue can be propagated by division or seeds. Like many shade-tolerant flowers, it does not like to be moved. If a division is deemed necessary, either to rejuvenate the clump or produce new plants, wait until the plant is established after about five years. Here's how:

1. In early spring as new growth is just beginning, dig up the entire root clump with a shovel.
2. Brush or wash off loose soil, then divide the root clump into sections, each section with a healthy clump of roots as well as a section of crown.
3. Immediately replant the pieces in the desired locations. If planting in groups, space the pieces well apart, as they will become large plants.
   

How to Grow Meadow Rue From Seed

These plants are easy to grow from seed, though they will take some time to germinate and produce mature plants. It's actually best to plant seeds collected from flower heads, as commercially sold seeds often have a lower germination rate. Patience is key. When direct-sown in the garden, seeds can take a full year to germinate, and two to three years until they reach flowering maturity. Seeds can simply be broadcast over an area where you want the plants to naturalize or planted at a shallow depth in the precise locations you choose.

Potting and Repotting Meadow Rue

As a perennial plant with a somewhat undisciplined shape and usually large size, meadow rue is not often used in container culture. Should you want to try it, use a large, well-draining pot filled with standard potting mix. You will need to water container-grown plants more frequently. These slow-growing plants don't need repotting very often; every few years will suffice.

Container-grown plants should be shifted to sheltered outdoor locations for the winter months, but don't be surprised if you lose them in climate zones with frigid winters. Exposed above ground in containers, the roots are more susceptible to cold.

Overwintering

Cut foliage and flower stalks back to just above ground level as winter approaches. This can also be done earlier if the foliage succumbs to summer heat. If you are growing a borderline-hardy species in a northern climate, a thick layer of winter mulch can help to moderate winter freeze-thaw cycles and help ensure survival.

How to Get Meadow Rue to Bloom

Meadow rue usually blooms readily if its basic needs are met—consistent moisture, a partial shade location, and rich soil. If you find that your plant doesn't bloom well, increase the watering frequency and feed it modestly with organic fertilizer, such as compost applied as a mulch over the root zone. Deadheading spent blossoms might extend the overall bloom period into early summer.