Mimosa tree (Acacia dealbata) is a fast-growing, evergreen tree, with fern-like leaves and bright yellow flowers that resemble fluffy balls, and have a strong fragrance. In the UK it grows to a maximum height of around 12m, so makes an excellent garden tree, where its spring flowers provide a burst of colour without casting shade.


Also known as blue wattle or silver wattle, mimosa tree is native to Australia, and therefore isn't fully hardy in the UK. It does best in southern and coastal regions, where winters are milder.

Is mimosa the same as Albizia?

Several plants are known as mimosa. These include the sensitive plant, Mimosa pudica, as well as Albizia julibrissin, which is most often called Persian silk tree in the UK, but is known as mimosa in the United States. All three plants have similar leaves.

How to grow mimosa tree

Grow mimosa tree in a sheltered, sunny spot in well drained, neutral to acidic soil. There's usually no need to prune although it does respond well to pruning: cut back after flowering only, the following year's flowers are formed in autumn, so it's important not to prune after late summer.

Where to grow mimosa tree

Mimosa tree in flower. Getty Images
Mimosa tree in flower. Getty Images

Mimosa trees do best in a southerly or coastal region of the UK. Choose a sheltered spot, such as in front of a south-facing wall, out of prevailing winds. Mimosa grows as a street tree in some parts of London – a sunny courtyard is ideal.

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How to plant mimosa

Because it's not fully hardy, mimosa tree is best planted in late spring, so is available as a potted plant only (not bare-root). Dig a square hole that's wider, but no deeper than the pot, and use a garden fork to lightly release soil from the sides of the hole to enable roots to penetrate them easily. Take the rootball out of the pot and place it in the hole to check it sits well and is at the right depth – it should sit no deeper than it was in its original pot. Once you're happy with its position, backfill with soil and firm gently. Water generously and add a stake to prevent wind rock.

How to care for a mimosa tree

Mimosa tree in flower. Getty Images
Mimosa tree in flower. Getty Images

Water your mimosa tree regularly for the first couple of weeks after planting. After that, your tree will require very little care. If you want to trim your mimosa or keep its growth in check, cut back after flowering but no later than late summer, as the following year's flowers develop in autumn. You may also find frost-damaged growth in winter, lightly trim this back to living wood.

As soon as they appear, pinch out any suckers that develop from the base.

Are mimosa trees invasive?

Acacia dealbata is a vigorous grower and can become invasive in some countries, including New Zealand, south-west Europe and parts of South Africa. However, in the UK, mimosa is not invasive.


Growing mimosa: pests and diseases

Mimosa trees are not susceptible to any pests or diseases. They can be susceptible to frost damage in winter – simply cut out damaged wood back to living wood.

Advice on buying mimosa trees

  • Mimosa trees are hardy only to -5ºC-1ºC, so need a sheltered, sunny spot in a southerly or coastal region of the UK
  • Mimosa trees are available from garden centres and nurseries, but you may find a greater variety of sizes by shopping online
  • Always check plants for signs of disease or damage before planting

Where to buy mimosa trees