Dicksonia squarrosa
Wheki, New Zealand tree fern, Rough tree fern, Harsh tree fern
Also known as Trichomanes squarrosum
- Height × spread
- 6m × 6m
- Position
- Tolerates full sun, likes part shade, likes light shade
- Hardiness
- Mild winter to -5C (RHS H3)
- Flowers
- Autumn
Availability
Please ask in store about availability
Many plants are seasonal. Call 01234 567890 to check current stock.
About this plant
This tree fern has long dark green arching fronds that are yellowish on their underside. They are harsh on the hands, so gloves may be advisable when handling. The brown trunk gradually ascends as the old foliage dies. The dead leaves remain hanging and can be cut away. This has rhizomatous roots and its children can emerge some distance from the parent. Fortunately the plant can do this even in our climate. This, the most wind tolerant of the Dicksonia tree ferns, still needs to be placed with care in a warm and sheltered spot. It looks best when grown in a group. It is faster growing than the other tree ferns and will reach a height of around 6m (20ft) with an equivalent spread, perhaps making 1.5m (5ft) height after 10 years.
- Foliage colour
- Green
- Autumn foliage
- Yellow
- Stem colour
- Brown
- Variegated
- No
- Scent
- No
- Shape
- Fan
- Height
- 6m
- Spread
- 6m
- Height in 10 years
- 1.5m
- Spread in 10 years
- 3m
- Flowers in
- Autumn
- Evergreen
- Evergreen
- Garden style
- Exotic garden
- Sun or shade
- Tolerates full sun, likes part shade, likes light shade
- Soil type
- Clay, Loam (normal)
- Soil pH
- Acid (ericaceous)
- Drainage
- Moisture retentive soil
- Hardiness
- Mild winter to -5C (RHS H3)
- Borders & containers
- Borders and containers
- Use for
- Architectural
- Deer
- May be damaged by deer when very young
- Hazards
- No
Spring
Spring · Outdoors
Apply acidic mulch
Where soil is only just acidic, apply mulch with a high acidic content such as leaf mould, or mulch for ericaceous plants. Alternatively the plant can benefit from a feed of iron supplement (iron chelate) such as sequestrol.
Spring-Autumn · Outdoors
Water during dry periods
For plants in the ground, when there has been little or no rain for a period of 7-10 days and the soil is dry, give it a deep watering and repeat weekly until there is a downpour of rain. Check plants in pots more frequently, especially in hot weather.
Spring · Planting
Repot yearly
Repot yearly if grown in a pot. Move it to a slightly larger pot with drainage holes. Some of the old compost can be shaken away, but don't disturb the roots too much.
Be careful to ensure the roots are spread out in the new pot, and that the plant is sitting on compost and not an air pocket. Firm the soil gently, and make sure that the plant sits at the same level above the soil as it did previously.
Summer
Summer-Autumn · Outdoors
Mist the plant in warm weather
Revive plants in warm or hot weather by misting the foliage, preferably using soft or rain water which doesn't mark the foliage. Don't mist when the plant is in full sun. The plant can be misted twice daily if you notice the process revives it.
If leaves are covered in water drops when sun is on them, the droplets can act as little magnifying glasses and cause foliage scorch.
Winter
Winter-Spring · Planting
Protect from winter cold
Bring the plant into a frost-free area before frosts occur, and do not put them outside until all danger of frost is past. Follow watering instructions, or allow the plant a period of dormancy during the winter.
Plants need to be brought inside in cold areas, i.e. colder than zone 8.
Planting & general
Outdoors
Water with rain water
This plant needs rain water or soft water (the minerals in alkaline or "hard" water are harmful). This is especially important for plants in pots.
Outdoors
Mist plant during hot weather
In hot dry weather, if the plant becomes warm give it a regular hose down to provide beneficial humidity and cooling.
Outdoor planting · Outdoors
Tree fern feed
After the first year, apply liquid feed to the crown and trunk regularly during the growing season. Follow the manufacturer's guidance for application rates.
Applies to tree ferns which you need to water and feed from above
Compost · Planting
Ericaceous compost
This plant requires acidic (ericaceous) soil. Where the soil is not acidic, or when planting in pots, use an ericaceous compost.