Thalictrum

( thal - LIK - trum )

At-A-Glance Information

Thalictrum, or Meadow Rue, is a genus of perennial flowering plants that need light shade and regular water to perform well. Meadow Rue forms clumps of foliage that are attractive in cut flower arrangements. Blooms appear in late spring to summertime, and have prominent stamens. Many species have puffy blooms, giving the plant an overall airy effect in garden beds. Use Thalictrum in mixed beds and borders, as members of cut flower gardens, or as accents in woodland, rock, or meadow gardens. Take care when planting these flowers in the garden, as some species are toxic to humans and pets.

Thalictrum Species and Varietals

The genus Thalictrum is a member of the plant family Ranunculaceae and includes between 100 and 120 distinct species. The best growing zones for Meadow Rue are 2-10 and 14-17. To find your zone, click here: Zone Map.

Thalictrum aquilegiifolium (Greater Meadow Rue, Columbine Meadow Rue, French Meadow-Rue, Siberian Columbine Meadow Rue)
Native to Europe and northern Asia, this plant grows 2-3 feet tall and a foot wide. Foliage is blue-green and greenish-white flowers lose their sepals quickly, leaving behind rosey stamens. They bloom for just a few weeks in mid to late springtime. They are followed by seed heads that will last for a long while. This species is heat-tolerant.

Thalictrum cooleyi (Cooley's Meadow Rue)
These plants are native to the southeastern United States, and produce white to yellowish flowers in June through July. This species is considered threatened with extinction due to habitat destruction and degradation.

Thalictrum delavayi (Thalictrum dipterocarpum) (Chinese Meadow Rue)
This species is native to western China and grows to 3-4 feet tall and 2 feet wide, with dark purple stems. Foliage is green and sepals are lavender to violet. Stamens are yellow. This plant will need some support for its flowering stems to stay upright. Bloom lasts for over two months in the springtime. Variety 'Hewitt's Double' (pictured) has double lilac-colored flowers.

Thalictrum flavum glaucum (Thalictrum speciosissimum) (Dusty Meadow Rue, Common Meadow-Rue, Poor Man's Rhubarb, Yellow Meadow Rue)
This species is native to Spain, Portugal, and northwestern Africa. It has an upright habit and reaches 3-5 feet tall and 2 feet wide. Younger stems are tinged mauve. Leaves are blue-green and summertime flowers are tiny, fragrant and yellow. This species may need staking in order to stay upright.

Thalictrum rochebruniamum (Lavender Mist Meadow-Rue)
This species is native to Japan and reaches 4-6 feet tall and 2 feet wide, and stems are sturdy (they do not need to be staked like other species to stay upright). Flowers are white or lavender and have pale yellow stamens. Variety 'Lavender Mist' is a great selection with violet sepals.

Thalictrum thalictroides (Rue-Anemone, Windflower)
These plants are native to woodland areas in eastern North America, and produce white to pink flowers which bloom in springtime. Plants reach about 12 inches tall when in bloom. They are great when used as a woodland groundcover, and will naturalize under trees.

Caring for Thalictrum

Thalictrum, or Meadow Rue, is typically purchased as seed and sown in fall or as a specimen from a reputable nursery planted out in springtime. These plants need winter chill to perform well, and thrive in partial shade at the edges of woodland areas. They can tolerate full sun in cooler climates, though they do appreciate shade during the warmest hours of the day (typically between 2 and 3 PM). These delicate plants also need protection from wind, so make sure to choose a spot that has some shelter or a windbreak nearby. Ensure that soil is rich in nutrients, well-draining, and has a pH of between 6.0 and 7.0 (slightly acidic to neutral). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water new plantings regularly as they establish a strong root system in their new home. At maturity, these plants perform well in consistently moist soils.

Fertilize yearly in early springtime with an application of 2 inches of compost around the base of plants. Pull mulch back before applying, work the compost gently into the soil a bit, water it in, and then replace mulch. These plants are not heavy feeders, and this should be sufficient to provide the necessary nutrients for the active growing and flowering seasons. Pruning is simple; remove any damaged, diseased, or dead foliage at any time during the growing season, and remove spent flower spikes to neaten up the appearance of plants and encourage reblooms. Meadow Rue can be cut back to the ground in summertime if foliage begins to yellow and die back in summer heat. Thalictrum plants will need to be divided every four to five years to ensure ongoing plant health. For instructions on how to successfully divide Meadow Rue plants, see the Propagation section below.

Harvesting Thalictrum Cut Flowers and Foliage
Thalictrum, or Meadow Rue, is commonly used in cut flower arrangements due to its delicate, airy blooms and attractive, fern-like foliage. The species most commonly cultivated in cut flower gardens are Thalictrum delavayi and Thalictrum rochebrunianum. Plants flower in the summer months, typically in July through September, and the best time of day to collect cut stems is in the morning a day after the plant as been watered. To maximize their vase life, make sure to harvest flowering stems just before flowers fully open, cutting stems back to the base of the plant with clean, sharp shears. Thalictrum flowers typically have a vase life of around 7 days if harvested correctly.

Propagation

thalictrum, or Meadow Rue, can be propagated either by using division or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the division method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your Meadow Rue plant, follow the instructions below:

Propagating Thalictrum by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) peat moss and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
Harvest your seeds. The seed heads are pretty easy to spot, they're left behind after flowers have faded. Once they have dried out and begun to split open, you can harvest the seeds inside. Cut them off of the plant, placing them in a paper bag. Harvest as many as you can, and place the paper bag in a dry, cool, dark area. They will begin to split open and release the seeds contained inside. Once they have been released, take them out of the bag and put them in a container so you can work with them.
Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 14-21 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Propagating Thalictrum by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil (any kind will do, though it does need to be well-draining), compost, and pots (only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in spring, and needs to be done every three to five years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:

Gather your materials. Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the roots. Once you have worked it up out of the ground, lay it out.
Start to tease apart the roots with your gloved fingers. Once the roots are untangled, separate your plant into segments, ensuring that each one has at least one thick root section.
Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divisions and water them in thoroughly, ensuring that good drainage is occurring.
Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout the following growing season.