The Story
Plant Bio
Crinum americanum, commonly known as Southern Swamp Lily or String Lily, is a bulbous perennial native to the southeastern U.S. It produces strap-like leaves and umbels of large, fragrant, spidery, trumpet-shaped white flowers.
This cultivar is distinguished by its robust growth and large, showy flowers that bloom in late summer, making it a striking addition to water gardens and tropical-themed landscapes.
Uses & Benefits:
Essentials
At a Glance
Plant Type
Perennial
Height
30 inches
Width
18 inches
Light
Full Sun, Partial Sun
Zones
7, 8, 9, 10
Water
Moist to wet
Humidity
Moderate to high
Lifespan
Perennial
Native To
Southeastern USA
Toxicity
All parts are toxic if ingested
Bloom period
Late summer – Late fall
In flower about 4 months of the year
Planting
How to Grow
- Tuck bulbs 4 inches deep in moist, well-draining soil.
- Water regularly to keep soil consistently moist.
- Place in full sun or partial shade for best blooms.
- Fertilize with a balanced fertilizer in spring.
- Mulch to retain moisture and suppress weeds.
- Divide clumps every 3-4 years in early spring.
Pro Tip
Ensure soil remains moist for optimal flowering and growth.
Keep It Thriving
Care Guide
Do
- Water regularly during growing season 💧
- Apply fertilizer in spring 🌱
- Mulch to conserve moisture
Don't
- Avoid waterlogging ❌
- Do not let soil dry out completely ❌
- Skip fertilizing in late fall ❌
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Fertilize | ||||||||||||
| Plant | ||||||||||||
| Winter Prep |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Companion Plants
Multiply
Propagation Methods
Good to Know
Common Questions
St. Marks Swamp Lily questions
What zones can St. Marks Swamp Lily grow in?
St. Marks Swamp 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 St. Marks Swamp Lily deer resistant?
Yes — St. Marks Swamp Lily is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.
When does St. Marks Swamp Lily bloom?
St. Marks Swamp Lily typically blooms in late summer through late fall. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does St. Marks Swamp Lily need full sun?
St. Marks Swamp Lily does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
More Crinum to compare
Crinum Lily Ollene
Crinum x hybrida 'Ollene'
Crinum x augustum Spider Lily
Crinum x augustum
Crinum Lily Mystery
Crinum x hybrida 'Mystery'
Stars and Stripes Crinum Lily
Crinum x digweedii 'Stars and Stripes'
Sangria Crinum Lily
Crinum x hybrida 'Sangria'
Crinum Moorei Album
Crinum moorei 'Album'
Keep exploring
Explore the genus
Hardy in your zone?
Grow St. Marks Swamp 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.