Trilliums are elegant spring wildflowers that grow from rhizomes and put on a stunning floral display. Their whorls of three leaves and flowers make them stand out in woodland gardens. If you want to add trilliums to your own garden, planting the rhizomes correctly is key to their success. Follow this guide to learn when and how to plant trillium rhizomes for healthy, long-lived plants.
Trilliums are spring ephemerals, meaning they emerge early in spring, bloom, go dormant in summer, and disappear back underground. They grow wild across most of North America and parts of Asia in moist, shady deciduous forests.
There are over 40 different trillium species, with flower colors ranging from white, pink, red, purple, yellow and more. The foliage is generally green but can be mottled purple or silver. They get their name from the whorl of three leaves and three petals on each flower.
In the wild, trilliums can take up to 7 years to mature and flower. But when planting rhizomes, you’ll get flowers much faster.
When to Plant Trillium Rhizomes
The best time for planting trillium rhizomes is early spring or late fall when they are dormant. This gives them time to establish roots before growth starts in spring.
Avoid planting in summer when they are dormant and the soil is dry. Planting in late fall allows roots to develop before the ground freezes.
Spring planting should be done as soon as the soil can be worked. Get them in the ground 4-6 weeks before the last expected frost.
How to Plant Trillium Rhizomes
Follow these steps for successfully planting trillium rhizomes:
Choose a Site
Pick a spot that mimics trillium’s natural habitat – moist, humus-rich soil and partial to full shade. Amend clay soils with compost to improve drainage. Areas under trees or on the north side of buildings are ideal.
Prepare the Soil
Dig a hole or planting bed 12-18 inches deep, loosening the soil. Mix in compost or leaf mold Refill the hole, leaving the top 4-6 inches loose.
Plant the Rhizomes
Place the rhizomes in loose soil 2 inches deep and 12 inches apart. Spread the roots out gently. Cover with soil, water well and mulch with 2 inches of leaves or pine needles.
Provide Care
Keep soil moist, but not saturated, as growth starts in spring. Allow soil to dry out completely during dormancy in summer. Apply leaf mulch annually. Divide clumps every 3-5 years.
Caring for Trilliums After Planting
Proper care after planting will keep your trilliums healthy and flowering.
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Water plants regularly through spring growth and flowering. Allow soil to dry completely in summer dormancy.
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Apply 2-3 inches of leaf mulch around plants annually to retain moisture and mimic forest floor.
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Divide congested clumps every 3-5 years in fall by gently teasing rhizomes apart and replanting.
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Remove spent flowers but allow seed heads to develop for propagation.
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Watch for slugs, snails and hungry wildlife that may chew leaves and flowers.
Troubleshooting Trilliums
Trilliums are not prone to many problems when planted properly. But issues can arise if cultural conditions are not ideal:
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No flowers – Insufficient light, missing dormancy period, or immature plants under 7 years old.
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Poor growth – Improve drainage in heavy soil, ensure adequate moisture in spring, mulch plants.
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Leaves eaten – Protect from slugs, deer, rodents with barriers as needed.
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Brown leaf spots – Treat anthracnose fungus with fungicides. Improve air circulation.
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Failure to emerge – Rodent damage to rhizomes, extreme cold damage, or overly wet soil.
Key Takeaways on Planting Trillium Rhizomes
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Plant trillium rhizomes in early spring or late fall when dormant.
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Choose a shady spot with rich, moist, well-draining soil.
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Dig a 12 inch deep hole, place rhizomes 2 inches deep, 12 inches apart.
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Water during spring growth, allow soil to dry when dormant in summer.
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Mulch plants annually with 2 inches of leaves or pine needles.
With proper planting and care, trilliums will naturalize over time and provide a stunning spring floral display year after year. Their unique foliage and flowers make them stand out as one of the stars of the woodland garden.
What to Know About Trillium
Trilliums grow from rhizomes, which are fleshy, underground stems. It may take more than one growing season for newly planted trillium to settle in and begin flowering. Once established, they are very long-lived and will usually multiply.
Some trillium species are endangered. Always purchase from a reputable source that can guarantee the plants were not collected in the wild. All trillium sold by Longfield Gardens are nursery propagated.
Sun and Shade: In the wild, trilliums are usually found growing in the dappled shade beneath deciduous trees and shrubs. For the plants to thrive, they need plenty of light during the spring. After flowering, the foliage will continue growing for several months and then die back to the ground.
Soil Conditions: Trillium should be planted in soil that’s rich in organic matter. It should be well drained yet consistently moist. Mulching the area with shredded leaves will improve the soil and help retain moisture.
Hardiness: Hardiness varies by species. Some trilliums are winter hardy in growing zones 4-8, while others are more sensitive to cold and only hardy in zones 6-8.
Large-Flowered White Trillium (Trillium grandiflorum). Native to the eastern half of the U.S. and Canada. Snow-white flowers with very large petals. The plants grow 12-20” tall with broadly-oval leaves that display prominent veining. Flowers usually turn pale pink as they age. Plantings can spread over time and cover large areas of the forest floor. Prefers neutral to slightly alkaline soil. Hardy in zones 4-7.
Red Trillium (Trillium erectum). Native to the eastern half of the U.S and Canada. The dark red flowers have an unpleasant odor that attracts pollinating flies. Plants need at least a half day of bright sun in spring. Flowers are followed by berry-like fruits. Established clumps may be divided in mid to late summer. Red trillium prefers neutral to acidic soils. Hardy in zones 3-6.
Your Guide to Planning, Planting, and Growing Trillium
Trilliums are spring-blooming wildflowers that grow naturally in woodlands throughout much of the United States and Canada. These distinctive plants are easy to recognize. They have a whorl of three leaves, topped by a single flower that has three petals and three sepals.
Trillium transplant and division
FAQ
When should you plant trillium bulbs?
You should plant trilliums in late summer soon after their bulbs go dormant. Depending on the region and type of trillium, the bloom time will start in early to mid-spring and end in late spring to early summer.
When to divide trilliums?
… time to divide a Trillium” – reply, “Whenever you are offered a piece!” The next best time is to wait till their growth has died down at the end of the summerSep 28, 2016
Is trillium hard to grow?
However, it’s not easy to germinate trillium seed. It’s best to purchase nursery propagated and grown plants. Seed grown plants can take up to 10 years to bloom. Small trillium plants bought online or at the local garden center should bloom in a few years.