Robinia pseudoacacia 'Umbraculifera'
Mop head acacia, Common acacia, False acacia, Black locust, Locust
Also known as Robinia pseudoacacia 'Inermis'
- Height × spread
- 12m × 8m
- Position
- Full sun
- Hardiness
- Very cold to -20C (RHS H6)
- Flowers
- Autumn
Availability
Please ask in store about availability
Many plants are seasonal. Call 01234 567890 to check current stock.
About this plant
This acacia makes a distinctive round headed tree. It gives a strong, dignified shape and is an excellent focal point. The pinnate leaves are quite long, a shiny dark green. This variant has spineless branches and seldom flowers. This needs a sheltered spot as the branches can break in exposed or windy situations. Give it a loamy soil that is well drained, and a sunny, sheltered site. It reaches around 12m (40ft) height with 8m (26ft) spread.
- Foliage colour
- Green
- Autumn foliage
- Yellow
- Stem colour
- Brown, Grey
- Variegated
- No
- Scent
- Yes, sweet-vanilla
- Shape
- Round
- Height
- 12m
- Spread
- 8m
- Height in 10 years
- 5m
- Spread in 10 years
- 4m
- Season of interest
- Summer
- Flowers in
- Autumn
- Evergreen
- Deciduous
- Garden style
- Seaside garden, Scented garden, Mediterranean garden
- Sun or shade
- Likes full sun
- Soil type
- Chalk, Gravelly soil, Loam (normal), Poor soil, Sandy soil
- Soil pH
- Acid (ericaceous)
- Drainage
- Well drained soil, Dry soil, Drought resistant
- Hardiness
- Very cold to -20C (RHS H6)
- Borders & containers
- Borders
- Use for
- Architectural, Bee attraction, Bird attraction
- Deer
- Protect from deer when young if in vulnerable area
- Maintenance
- Easycare – low/no maintenance
- Hazards
- Yes, stems are prickly/thorny and potentially harmful; Humans: Harmful if eaten; skin irritant
AutumnNow
Autumn · Planting
Remove suckers
Remove any suckers that have appeared round the base of the plant. They can often be pulled up, but it may be necessary to use secateurs or loppers to detach them from the parent plant.
Spring
Spring - late · Outdoors
Feed young plants with slow release fertiliser
Spread a slow release fertiliser around the base of the plant to the edge of the foliage spread, so that it can feed the roots. It is helpful for this to be applied for several years.
This is a simple way to provide a nutrient boost until the plant becomes well established.
Spring-Autumn · Outdoors
Water in dry periods
Established plants in the ground can cope with 7-10 days of dryness, and shrubs often manage 2 to 3 weeks. Water one section of the garden thoroughly each day rather than a little everywhere. Check plants in pots more often, especially in hot weather.
Summer
Summer - late · Planting
Prune to maintain the tree
Keep the plant looking attractive and healthy by removing dead branches, branches that cross or rub each other, and those which spoil its appearance.
Prune in late summer as the tree is less likely to be damaged, or to begin to bleed from the wood that has been cut.
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.
Outdoor planting · Planting
Add root growth stimulant to the planting hole
Mycorrhizal fungi helps roots establish quickly, so they absorb water and nutrients more efficiently. It comes as a powder, granule or gel. Add to the planting hole or container, and to the plant's rootball before planting in the hole. For "bareroot" plants use a gel.
Planting
Protect & support young trees
Attach a newly planted tree or tall shrub over 1m to a tree stake to give support and prevent windrock. Use a tree guard to stop tree bark being eaten by animals, especially in areas with deer - removing bark injures a tree and in worst case can kill it.
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.
Found in
More Robinia
Robinia
False acacia
Robinia pseudoacacia
Common acacia, False acacia, Black locust, Locust
Robinia pseudoacacia 'Frisia'
Golden acacia, Golden locust, Common acacia, False acacia, Black locust, Locust
Robinia pseudoacacia
Common acacia, False acacia, Black locust, Locust
Robinia pseudoacacia 'Lace Lady'
False acacia
Robinia pseudoacacia 'Tortuosa'
Common acacia, False acacia, Black locust, Tortured locust