The Story
Plant Bio
Schizostylis coccinea, the crimson flag or river lily, is a clump-forming member of the iris family from damp meadows and stream banks in South Africa, Lesotho and Eswatini. It grows from a rhizome rather than a corm, sending up narrow sword-shaped leaves and spikes of scarlet star-shaped flowers one to two feet high from August into October.
It flowers when almost nothing else does, right through October, and that late display depends entirely on the soil staying moist through the growing season; a dry August means no flowers in October. It is also a rhizome rather than a corm, so unlike most South African bulbs it never wants a dry dormant rest.
Uses & Benefits:
Essentials
At a Glance
Plant Type
Perennial
Height
18 inches
Width
12 inches
Light
Full Sun, Partial Sun
Zones
7, 8, 9, 10
Water
Medium to high
Humidity
Average to high
Lifespan
Perennial
Native To
South Africa, Lesotho and Eswatini
Toxicity
Non-toxic
Planting
How to Grow
- Plant in spring in consistently moist soil.
- Site in full sun to light shade.
- Keep the soil damp throughout the growing season.
- Water reliably in August, when next month's flowers are forming.
- Divide clumps every two or three years to keep them flowering.
- Mulch the crown for winter at the cold end of its range.
Pro Tip
Water through August without fail; a dry late summer is the usual reason a healthy-looking clump produces no October flowers.
Keep It Thriving
Care Guide
Do
- Keep the soil consistently moist 💧
- Divide clumps every two or three years ✂️
- Water reliably through late summer 🌊
- Mulch the crown in cold gardens 🍂
Don't
- Let the soil dry out in summer ❌
- Treat it like a corm needing a dry rest ❌
- Leave clumps undivided for many years ❌
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Divide | ||||||||||||
| Water |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Multiply
Propagation Methods
Good to Know
Common Questions
River Lily questions
What zones can River Lily grow in?
River Lily is hardy in USDA Zones 7–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is River Lily deer resistant?
Not reliably. Deer may browse River Lily, especially tender spring growth — plan on repellents or fencing where pressure is high.
When does River Lily bloom?
River Lily typically blooms in late summer to mid-fall through late summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does River Lily need full sun?
River Lily does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
More Schizostylis to compare
Keep exploring
Explore the genus
Hardy in your zone?
Grow River Lily with confidence
See it in a design of your actual yard, get zone-matched care reminders, and track it season by season in your garden journal.