Cardinal Flower 'Black Truffle'
Lobelia cardinalis 'Black Truffle'
Essentials
At a Glance
Plant Type
Perennial
Height
40 inches
Width
18 inches
Light
Full Sun, Partial Sun
Zones
4, 5, 6, 7, 8, 9
Water
Consistently moist to wet
Humidity
Moderate to high
Lifespan
Short-lived Perennial
Native To
North America
Toxicity
Toxic if ingested
The Story
Plant Bio
Lobelia cardinalis 'Black Truffle' is a stunning perennial with very dark, near-black foliage and vibrant scarlet-red flowers that attract hummingbirds and other pollinators. The foliage is notably dark, adding contrast and interest even when not in bloom.
Uses & Benefits:
Marketplace
Where to Buy
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Planting
How to Grow
- Tuck seeds into moist soil in early spring for best germination.
- Mist cuttings regularly to maintain humidity and encourage rooting.
- Transplant seedlings when they have 2-3 sets of true leaves, around 6 weeks.
- Water consistently to keep soil moist but not waterlogged.
- Fertilize monthly with a balanced liquid fertilizer during the growing season.
- Mulch around plants to retain moisture and suppress weeds.
Pro Tip
Use rich, well-draining soil and avoid overwatering to prevent root rot.
Keep It Thriving
Care Guide
Do
- Water regularly to keep soil moist 🌱
- Provide partial shade in hot climates
- Feed with a balanced fertilizer monthly
Don't
- Allow soil to dry out completely ❌
- Expose to harsh, direct afternoon sun in hot regions ❌
- Overcrowd plants, reducing airflow ❌
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Deadhead | ||||||||||||
| Divide | ||||||||||||
| Fertilize | ||||||||||||
| Mulch | ||||||||||||
| Pest Check | ||||||||||||
| Spring Cleanup |
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
Cardinal Flower 'Black Truffle' questions
What zones can Cardinal Flower 'Black Truffle' grow in?
Cardinal Flower 'Black Truffle' is hardy in USDA Zones 4–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is Cardinal Flower 'Black Truffle' deer resistant?
Yes — Cardinal Flower 'Black Truffle' is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.
When does Cardinal Flower 'Black Truffle' bloom?
Cardinal Flower 'Black Truffle' typically blooms in mid-summer to fall through late summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Cardinal Flower 'Black Truffle' need full sun?
Cardinal Flower 'Black Truffle' does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
More Lobelia to compare
Cardinal Flower
Lobelia cardinalis
Fan Cinnabar Rose Lobelia
Lobelia x speciosa 'Fan Cinnabar Rose'
Hybrid Cardinal Flower
Lobelia x speciosa 'Compliment Violet'
Lilac Candles Great Blue Lobelia
Lobelia siphilitica 'Lilac Candles'
Cardinal Flower Deep Rose
Lobelia cardinalis 'Deep Rose'
Laguna Dark Blue Lobelia
Lobelia erinus 'Laguna Dark Blue'
Keep exploring
Explore the genus
Collections featuring this plant
Grow Cardinal Flower 'Black Truffle' 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.
