Trillium

( TRILL - ee - um )

At-A-Glance Information

This genus of flowering perennials needs partial to full shade conditions and regular water to perform well. Species are commonly called Wakerobin, Toadshade, Tri Flower, Trinity Flower, Birthroot, Birthwort, and Wood Lily. They bloom in early springtime, sending out three-petaled flowers that appear in the center of a whorl of leaves. They are great in shady, wooded areas and like to be left undisturbed to form colonies via rhizomes. In summer, these plants will die to the ground. Take care when planting these flowers in the garden, as some species are toxic to humans and pets if ingested.

Trillium Species and Varietals

The genus Trillium is a member of the plant family Melanthiaceae and includes about 50 distinct species. The best growing zones for Trillium vary depending on the species. For more information, see the descriptions below. To find your zone, click here: Zone Map.

Trillium albidum (Giant White Wakerobin, White Toadshade)
These plants are endemic to the western United States, from central California through Oregon to southwestern Washington. Leaves are green to deep green, and flowering stems are topped with solitary white flowers (that are sometimes pink or purple-tinged).

Trillium cernuum (Nodding Trillium, Nodding Wakerobin, Northern Nodding Trillium, Whip-Poor-Will Flower)
These perennial herbaceous plants spreads by underground rhizomes, and produces above-ground foliage and flowers that reach up to 16 inches tall. Flowers bloom between April and June, and are white to pale pink.

Trillium chloropetalum (Trillium sessile californicum)
Native to California, this species grows best in zones 4-9 and 14-17. It reacches 1-1.5 feet tall and 1 foot wide. Leaves are marked with maroon spots, and stalkless flowers bloom in early spring. Blossoms are greenish white to yellowish. Trillium chloropetalum giganteum (pictured) has maroon flowers.

Trillium decumbens (Decumbent Trillium, Trailing Wakerobin)
These perennial herbaceous plants are native to the states of Tennessee, Georgia, and Alabama. It prefers to grow in mature deciduous woodlands and open rocky wooded slopes. Flowers appear from March through April, and are held upright at full bloom. Blossoms are dark maroon, and emit an unpleasant odor.

Trillium erectum (Red Trillium, Wake Robin, Purple Trillium, Bethroot, Stinking Benjamin)
Plants in this species are native to North America, and produce red flowers with white anthers. Individual plants reach 16 inches. Varieties have flowers that are dark reddish-brown, maroon, purple, pale yellow, or white.

Trillium grandiflorum (White Trillium, Large-Flowered Trillium, Great White Trillium, White Wake-Robin, Trille Blanc)
Native to rich, mixed upland forests in eastern North America, these plants produce white flowers that bloom from late springtime through early summer. Leaves are green and have deep veins. Flowering stems reach up to between 8 and 16 inches tall.

Trillium luteum (Yellow Trillium, Yellow Wakerobin)
These plants produce yellow flowers, unlike most other species in the genus, which produce red or white blooms. These plants are endemic to the southeastern United States, and has green leaves with grey-green marbling. Flowers appear between the months of April and May, and after flowering and setting seed, plants go dormant in summertime.

Trillium ovatum (Trillium californicum) (Western Trillium, Western White Trillium)
This species is best in zones 4-9 and 14-17 and is native to the western United States. It reaches 1.5 feet tall and a little less wide, with white flowers topping stalks. Blooms age to a rose color.

Caring for trillium

Trillium can be purchased as bare root rhizomes, seed, or as starts from a reputable nursery. They should be planted about 6 to 12 inches apart and 2-4 inches deep. Allow room around them so that they can form clumps. Plant Trillium in a space in the garden that receives partial shade. They are naturally woodland plants, and grow along wet forested areas. The more heat they experience, the more shade they will need. They do well in fertile, well-draining soil that has a lot of added organic matter and a pH of between 5.5 and 7.0 (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, they appreciate a consistently moist substrate but do not like to have soggy soil around their roots. Withhold waterings when plants are dormant in wintertime.

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. After all flowering stems and foliage have died back to the ground, it can be removed. Mulch over the tops of roots for added insulation over the cool winter months. Make sure to weed regularly around Trilliums, as they do not compete well for nutrients and moisture. Although it is not necessary, Trilliums can be divided if they seem to be struggling. For instructions on how to successfully divide Trillium plants, see the Propagation section below.

Propagation

Trillium, or Birthroot, can be propagated by division or 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, especially if you are propagating a hybrid cultivar. To propagate your Birthroot flowers, follow the instructions below:

Propagating Trillium 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) moss peat 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 on plants 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 continue 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.
Trillium seeds will need a period of cold-stratification in order to germinate. To complete this process, first place seeds in a bag or other sealable container filled with moistened sand or peat moss. Then, place the container in the refrigerator (or similarly cool, dark space) for 2-3 months. The ideal temperature for cold-stratification is around 40 degrees Fahrenheit. After this period has passed, remove seeds from the container.
Get your container prepared. 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 2-6 weeks 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 65 and 72 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 Trillium 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 very early spring (after the plant has entered dormancy, but before it has begun its new spring growth), and needs to be done every few years regardless of whether you have the goal of propagating the plants for best performance. To propagate by division, follow these steps:

Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the root(s). 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 attached.
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 thoroughly.
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 in the next growing season.

Trillium seed pods will form where flowers once bloomed.

Trillium seeds are very small, and are typically reddish-brown to dark brown in color..

Problems and Pests

Trillium plants, although typically considered resilient, can be susceptible to developing issues with the following pests and diseases in the landscape: