Umbraculifera Robinia

Mop Top Robinia (Robinia pseudoacacia 'Umbraculifera') is the tree for a small garden that needs a real canopy and has no room for a real tree. It is grafted as a standard, so a dense rounded head sits on a clear straight trunk and settles at about 5m tall and 3.5m wide. The shape arrives ready made: no clipping, no thorns, no fruit to sweep up.

Why you'll love it

• Canopy on a compact footprint. Around 5m tall and 3.5m across, enough to shade a courtyard or a parking bay without dominating the block.
• Neat by nature. The head grows as a dense sphere, so the form is there from the start and needs no shaping.
• Thornless. Unlike the wild form of the species this selection carries no thorns, which matters beside a path or driveway.
• Genuinely hardy. Frost hardy, heat tolerant, drought tolerant and wind firm, which is why it turns up in exposed carparks and country driveways.
• Clean autumn colour. Fresh green through summer, then clear yellow before the leaves drop.

Where it works best

Driveways and avenues. Space trees 4m to 5m apart for an even row where the crowns just clear each other. A matched pair either side of a gate works equally well.

Small gardens and feature planting. One tree in a lawn or paved courtyard gives shade at head height while leaving the ground beneath usable.

Shade over hard surfaces. Heat and drought tolerance make it dependable over paving, gravel and driveways where reflected heat finishes off softer trees.

Growing Mop Top Robinia in Australia

Position and climate. Full sun and an open position. It suits cool temperate, warm temperate, Mediterranean and arid gardens, and it is not a tree for the tropics or the humid subtropics.

Soil. Almost any soil that drains, including poor and stony ground. It will not tolerate waterlogging, so on heavy clay plant on a raised mound and keep mulch 75mm deep and clear of the trunk.

Water and feed. Deep soak twice a week through the first two summers while the roots go down, after which it is genuinely drought tolerant. One complete slow release fertiliser in early spring is enough.

Pruning and suckers. The head needs no shaping. What it does need is attention below the graft: the rootstock can throw suckers from the trunk and root zone, and those should be rubbed or cut off flush as soon as they appear.

What to expect when it arrives

It is grown in three sizes: 400mm pots, 45L and 100L. A 400mm tree already carries a formed head on a clear trunk and is the practical size for most gardens. The 45L and 100L trees have a heavier head and far more immediate presence.

This is a deciduous tree, so between late autumn and early spring it arrives bare or nearly bare. That is normal, and it is often the best time to plant. Delivered Australia wide, with delivery from $29.95. Advanced and large stock is freighted at cost, and every tree carries our 30 day healthy plant guarantee.

Plant care guides and related reading

• Read about the best trees for lining a driveway.
• Compare more small trees for urban gardens.
• Browse the full deciduous tree range.
• See other plants for autumn colour.

Common questions

Will it get taller than 5m?

Rarely. Because the head is grafted onto a standard trunk, the tree gains width and density rather than height, and 5m is a realistic mature size in a garden.

What are the shoots coming from the base?

Suckers from the rootstock below the graft. Cut them off flush as soon as you see them, because left alone they draw energy from the grafted head and can eventually replace it.

Does it lose its leaves in winter?

Yes. Expect clear yellow before the leaves drop, then a bare, well shaped framework until spring, which is useful if you want winter sun reaching the house.