How to Grow Trillium

Woodland large-flowered trillium flowers

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Trillium plants (Trillium spp.) are low-growing woodland flowers. Many trillium species are native to the U.S., and you will often stumble upon a patch of trillium while walking in a forested area. But don't be tempted to take a plant from the wild. Many species are protected, and some are endangered. Different species favor different areas, and some are showier than others. But what they all have in common is that their main plant parts come in threes: three leaves, three petals, and three sepals.

Trillium leaves can be oval, elliptical, lance-shaped, or diamond-shaped in solid green or with mottling and veining of various hues. The leaves meet at one point on the stem and whirl out around it. The flowers can be tubular or cup-shaped and either stemless or held erect on a stem. Trillium plants are usually started by division, as they are slow growers. Starting them from seed is a lengthy process that can take years before you get blooming plants. The best time to divide or plant trillium is in the late summer to early fall.

Botanical Name  Trillium spp.
Common Names  Trillium, wood lily, birthroot, birthwort, wake robin, tri flower
Plant Type  Herbaceous, perennial
Mature Size  1–2 ft. tall and wide (varies by species)
Sun Exposure  Partial, shade
Soil Type  Loamy, moist, well-drained 
Soil pH  Acidic, neutral
Bloom Time  Spring
Flower Color  White, yellow, pink, red, purple, green
Hardiness Zones 4–9 (USDA)
Native Area  North America, Asia
Toxicity  Toxic to people, animals

Trillium Care

Trillium plants belong in a fairly shady settling that mimics their natural woodland conditions. However, don't plant them too close to shallow-rooted trees and shrubs that will compete for moisture. Instead, look for spots under deep-rooted trees, such as magnolias. Moreover, some of the smaller trillium species are suitable for alpine and rock gardens.

These plants are fairly low-maintenance with the right planting site. Make sure to water regularly to prevent them from drying out. And enrich the soil with organic matter to mimic a forest floor. Trillium plants don't typically have issues with pests or diseases. Deer will sometimes munch on them, but they usually won't eat the whole plant.

Light

As woodland flowers, trillium plants do best in partial to full shade. Direct sunlight can burn the foliage.

Soil

Trillium plants prefer a neutral to slightly acidic soil pH. They also need a soil that is rich in organic matter and holds moisture well, much like the conditions they would be growing in on the forest floor.

Water

Maintain lightly moist soil for your trillium plants, but be sure not to overwater. Sitting in soggy soil for too long can result in root rot and other plant diseases. During especially hot weather (along with dry spells), your trillium plants will likely need a little more water than normal, or they will start to wilt.

Temperature and Humidity

In general, trillium plants prefer temperate conditions. The species vary with how much heat and cold they can handle. Humidity typically is not an issue as long as their water needs are being met.

Fertilizer

Fertilizer usually is not necessary for trillium plants unless you have especially nutrient-deficient soil. What these plants do need is lots of organic matter. Mix compost into the soil at the time of planting, and add a fresh layer each year in the spring. You also may add leaf mold, or composted leaves, to further enrich the soil and mimic forest conditions.

Is Trillium Toxic?

While people and wildlife sometimes eat trillium leaves, the roots and berries of trillium plants are toxic both to people and animals when ingested.

Symptoms of Poisoning

Symptoms of toxicity in both people and animals include nausea, vomiting, diarrhea, and stomach pain. If you suspect poisoning, contact a medical professional as soon as possible.

Trillium Varieties

There are dozens of trillium species and even more varieties, including:

  • Trillium grandiflorum: These plants have showy white petals that fade to pink as they age. They are ideal for USDA growing zones 4 through 7.
  • Trillium erectum: The fragrance of this species is not very sweet, but it's also not that strong. This is a tall species with red or white flowers. It's good for growing zones 4 through 7.
  • Trillium vaseyi: This trillium species can reach almost 2 feet tall, and it sports 4-inch maroon flowers. It's a nice choice for growing zones 5 through 8.
  • Trillium chloropetalum: This plant is very showy, with 7-inch long mottled leaves and flower colors ranging from white to mahogany. It's a West Coast native and grows well in zones 6 through 9.
  • Trillium sessile: This trillium species only grow to around a foot tall, and it has long, dark green leaves that are mottled in purple or white. It's ideal for growing zones 4 to 8.