Overview
Trillium undulatum is a perennial herbaceous in the genus Trillium, part of the Melanthiaceae family. It typically grows around 0.2 m tall. Trillium undulatum grows best in full sun and full shade, and tolerates most soils and acidic to neutral pH. Its UK hardiness is rated H7. Suggested uses include woodland gardens and shade gardens. It is native to Eastern North America.
About
Trillium undulatum is a perennial herbaceous member of the Melanthiaceae, growing to about 0.2 m and flowering in April to May. Native to eastern North America, it suits shaded or semi-shaded sites and is recommended for woodland and shade gardens. Plant in moist but well-drained soils that are acidic to neutral; it tolerates sandy, loamy or clay textures. With an H7 hardiness rating it is fully hardy across the UK.
Wikipedia contributors, CC BY-SA 4.0 — Trillium undulatum
About the genus
Trillium is a genus of about fifty flowering plant species in the family Melanthiaceae. Trillium species are native to temperate regions of North America and Asia, with the greatest diversity of species found in the southern Appalachian Mountains in the southeastern United States.
Wikipedia contributors, "Trillium", CC BY-SA 4.0 — Trillium
In the garden
A native of eastern North America, Trillium undulatum is a short-lived perennial herbaceous plant that reaches roughly 0.2 m and flowers in April to May. It belongs to the Melanthiaceae and is most often used where a low, spring-flowering element is wanted beneath taller plants or trees. Select a site with some protection from midday sun: the plant is listed as tolerating full sun through to full shade but performs best in shaded or semi-shaded aspects and with partial shade exposure. Soils should be moist but well drained, with an acidic to neutral pH; the species will grow in sandy, loamy or clay soils provided drainage is reasonable. Its hardiness is H7 (fully hardy) and corresponds to USDA zones 4–8, so it withstands typical UK winters without winter protection. Use Trillium undulatum in woodland garden schemes, under deciduous canopy or at the front of a shaded border where its low height is an advantage. Plant with a mulch of leaf litter to retain moisture and help maintain soil structure. Expect the plant to carry interest into the garden during its April–May flowering window before the summer canopy fully develops.
Growing conditions
Best soil and position for Trillium
- Sunlight
- Full sun, Full shade
- Soil type
- Sandy, Loamy, Clay
- Soil pH
- Acidic to neutral
- Soil moisture
- Moist but well-drained
- Aspect
- Shaded or semi-shaded
- Exposure
- Partial shade
- UK hardiness
- H7
Plant details
Trillium undulatum size, habit and characteristics
- Plant type
- Perennial herbaceous
- Height
- 0.2 m
- Suggested uses
- Woodland gardens, shade gardens
- Native to
- Eastern North America
Care notes
Pruning and caring for Trillium undulatum
- Cultivation
- Prefers cool, moist, well-drained acidic soils; avoid disturbance
- Propagation
- By seed or division
Frequently asked questions
How do I grow Trillium undulatum?
Prefers cool, moist, well-drained acidic soils; avoid disturbance.
Where is the best place to plant Trillium undulatum?
Trillium undulatum prefers full sun and full shade. It suits partial shade positions.
What soil does Trillium undulatum need?
Trillium undulatum is adaptable and grows happily in most soil types, including sandy, loamy and clay. It prefers acidic to neutral soil. Aim for soil that stays moist but well-drained.
How big does Trillium undulatum grow?
Trillium undulatum reaches a height of 0.2 m.
Is Trillium undulatum hardy in the UK?
Trillium undulatum has an RHS hardiness rating of H7, meaning it is fully hardy throughout the UK, tolerating temperatures below -20°C.
How do I propagate Trillium undulatum?
By seed or division.
