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Trillium
Trillium
Also comes in pink, purple, red and yellow.
Trillium blooms from April through May.
Months here are Northern Hemisphere months; in the Southern Hemisphere, shift them by six months.
Growing Trillium
Plant it in full shade. It prefers moderate water. It is hardy in USDA zones 4–8. Expect it to reach about 12 in tall and 12 in wide at maturity, in roughly 2 years (a house reading).
Pets
- Not yet checked for pets.
- Listed as poisonous to people by NC State Extension.
Lists differ and none is complete. If a pet eats a plant and seems unwell, call a veterinarian or a pet poison helpline.
What was checked
Nine facts were checked against named botanical sources, each recorded beside the sources that carried it: mature height and spread, hardiness zones, sun, water, bloom months and color, the trait tags, and years to mature size, which rests on a recorded house rule where no publisher states one and is marked so. Soil, diseases, pests, toxicity and the plant's own names have not yet been read for this plant, and its trait tags are the ones a feature uses rather than every word a page prints. Each fact above carries its own mark. The planting, spacing and size sections are derived from these checked facts by a fixed rule, not checked separately, and the plant type is the library's own classification.
When to plant Trillium
Plant Trillium in early spring as soon as the soil is workable, or in early fall at least six weeks before your first frost, so roots establish in cool weather. In zone 6, the middle of its hardy zones 4 to 8, spring means March to May and fall means August or September. Once settled, it blooms from April to May.
Month-by-month timing for your zone is on the planting calendar; if you garden near zone 6, the middle of this plant's hardy range, start with zone 6 in March. Derived from the plant's category, zones and bloom months plus typical zone frost dates, not checked separately.
How big does Trillium get?
12 intall5 ft 7 inan adult12 inwideSee Trillium in a garden plan: the planner shows it in 3D beside everything else you add, growing toward this size over the years.
How far apart to plant Trillium
Derived from the mature spread above by a fixed rule, not checked separately: spacing is the spread, center to center.
Space Trillium about 12 in apart, center to center, so each plant has room to reach its full width.
Add Trillium to a garden plan and the planner draws it at its full width, so you see the spacing before you buy.
Where these facts come from
Trillium's height, spread, hardiness zones, sun, water, bloom months and color and trait tags were checked against 6 published sources on October 24, 2026. Each one is linked below with every fact it carried, which can include a fact this page still marks as not yet checked, because a source carrying a value is not the same as the value being held to the standard. Facts not in that list, and the planting, spacing and size sections, are not covered by these sources.
- acornfarms.comAcorn Farmsheight, spread, hardiness zones, sun, water, bloom months and color and trait tags
- NC State Extensionheight, spread, hardiness zones, sun, water, bloom months and color and trait tags
- University of Illinois Extensionsun, water, bloom months and color and trait tags
- RHSRoyal Horticultural Societyheight, spread, sun and water
- pottertons.co.ukPottertons Nurserybloom months and color
- Plant Delights Nurserysun
How the checking works, and what each standard covers, is on the verified plants page.
Where it grows wild
Native to North America as a group
The 45 wild species sold under this name grow in 44 states and 10 provinces.
United States: Alabama, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Jersey, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming and 32 more
Canada: Alberta, British Columbia, Manitoba, New Brunswick, Newfoundland, Nova Scotia, Ontario, Prince Edward Island, Quebec, Saskatchewan
Range data from the World Checklist of Vascular Plants, Royal Botanic Gardens, Kew (CC BY 4.0, adapted) and USDA PLANTS. How the native range is credited.
Good to know about Trillium
Curated from university extensions, botanic gardens and other primary sources, with the source named on every note. A note reports what its source says; where that differs from a fact above, the fact above is this entry's stored value, and its mark says whether it has been checked.
Safety
The berries and rhizome are mildly toxic if eaten, rich in steroidal saponins that upset the stomach. NC State rates the poison severity low. per NC State and Frontiers in Chemistry
Worth knowing
Ants plant the next generation: each seed carries a fatty treat called an elaiosome, so ants haul it off, eat the treat, and leave the seed to grow. per Illinois Extension and Ecology and Evolution
Never cut the leaves
The three green leaves are its only food-making surface for the whole year. Cut or mow them and you starve the rhizome; let them die back on their own. per NC State
Vanishes by mid-summer
By mid-summer the whole plant yellows and vanishes underground until spring. Mark the spot so you don't dig into the dormant rhizome by mistake. per NC State
Deer browse it heavily
White-tailed deer browse it heavily, stripping both flower and leaves. That prevents seed and starves the rhizome, so fence it or expect local decline. per NC State
Never dig from the wild
Buy only nursery-propagated plants and never dig or pick trilliums from the wild. Such transplants rarely survive, and colonies recover on a timescale of decades. per Illinois Extension and USDA Forest Service
What pairs well with Trillium
Good companions share its growing conditions and add something it lacks: an earlier or later bloom, a lower carpet in front, or structure through winter.
Rosebay Rhododendron
Takes part shade to full shade and moderate water; blooms in early summer as this one finishes; both are strong pollinator plants, and they feed in different months; evergreen, so the bed keeps its shape through winter.
American Wintergreen
Takes part shade to full shade and moderate water; blooms in early summer as this one finishes; both are strong pollinator plants, and they feed in different months; evergreen, so the bed keeps its shape through winter.
Zigzag Goldenrod
Takes part shade to full shade and moderate water; blooms in late summer, extending the bed's season; both are strong pollinator plants, and they feed in different months; its seed heads stand through winter, for structure and the birds.
Northern Sea Oats
Takes part shade to full shade and moderate water; blooms in midsummer, extending the bed's season; both are strong pollinator plants, and they feed in different months; its seed heads stand through winter, for structure and the birds.
Mountain Laurel
Takes part shade to full shade and moderate water; overlaps, then carries the display into early summer; both are strong pollinator plants; evergreen, so the bed keeps its shape through winter.
Blue Wood Aster
Takes part shade to full shade and moderate water; blooms in late summer, extending the bed's season; both are strong pollinator plants, and they feed in different months; its seed heads stand through winter, for structure and the birds.
Black Cohosh
Takes part shade to full shade and moderate water; blooms in early summer as this one finishes; both are strong pollinator plants, and they feed in different months; taller at 5 ft, for the layer behind it.
Snowdrop
Takes part shade to full shade and moderate water; blooms in late winter, before this one opens; both are strong pollinator plants, and they feed in different months; lower at 5 in, for the front of the border.
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Design a garden with this
Drop this plant onto a 3D plan, see how it fills in, and watch your whole garden bloom across the year.