Thalia dealbata
Water canna, Powdery alligator flag
- Height × spread
- 2m × 1m
- Position
- Full sun
- Hardiness
- Cold to -15C (RHS H5)
- Flowers
- Summer
Availability
Please ask in store about availability
Many plants are seasonal. Call 01234 567890 to check current stock.
About this plant
A distinguished foliage plant when well grown that adds style to any planting. It sends up long sturdy stems that carry large rigid lance-shaped leaves with curved sizes that spear the air. There are small purple flowers held on long stems in late summer that are not greatly ornamental. This is grown in boggy or very moist soil, or water to a depth of 15cm. It dies down in winter and may survive quite severe weather if far enough beneath the surface. It can be lifted and over-wintered in a frost free environment.
- Flower colour
- Violet
- Foliage colour
- Black, Green
- Variegated
- No
- Scent
- No
- Shape
- Column
- Height
- 2m
- Spread
- 1m
- Season of interest
- Spring, Summer, Autumn
- Flowers in
- Summer
- Evergreen
- Deciduous
- Garden style
- Water garden
- Sun or shade
- Likes full sun, tolerates part shade
- Soil type
- Loam (normal)
- Soil pH
- All types
- Drainage
- Moisture retentive soil
- Hardiness
- Cold to -15C (RHS H5)
- Borders & containers
- Borders
- Water depth
- Up to 15cm
- Hazards
- No
Spring
Spring · Outdoors
Feed with aquatic plant food
As the plant is grown in water, feed with an aquatic feed as directed on the packet. Do not exceed the amounts given as this can affect the water.
Spring-Autumn · Outdoors
Water frequently to keep the soil moist
The plant thrives in moist or boggy soil, doesn't tolerate dryness and should be watered frequently, not only after a period of drought, but if the soil begins to dry out spring to autumn. Check plants in pots more frequently, especially in hot weather.
Summer
Summer · Planting
Prune after flowering
When the plant has finished flowering, remove old leaves.
Planting & general
Planting
Deadhead blooms during flowering season
Remove flowers as they turn brown and fade. Snip the stem just below the bloom. This will keep the plant tidy and encourage more flowers.
The removal of spent flowers encourages the plant to produce fresh ones, rather than spend its energy on the development of seeds.
Compost · Planting
Compost for aquatic plants
Use aquatic plant compost for pond plants (other composts contain nitrates that cause problems in ponds). Pond plants are generally planted in baskets and weighted to keep in position.