The Japanese maple (or Acer) is a popular ornamental tree grown for its pretty spring flowers, glorious autumn foliage and graceful lines.  Japanese maples are perfect for small gardens, and many of the varieties available at your local wholesale nursery can be grown in containers and thrive in sheltered sites like patios. 

Here’s how to grow and care for an ornamental Japanese maple in a container.

How to plant your Japanese maple

What you’ll need

  • Japanese maple sapling
  • large clay plant pot or urn and clay ‘feet’
  • loam-based compost (available from the nursery)
  • decorative mulch
  • broken crocks (old clay plant pots are fine for this)

How to do it

  1. Start by placing a layer of crocks in the bottom of the pot.  The crocks help the compost to drain so that it doesn’t become waterlogged around the tree’s roots.  
  2. Stand the container on clay ‘feet’ to help with drainage.  
  3. Fill the pot to half-way with compost.  Remove the maple from its container and place it in the centre of the pot.  
  4. Keeping the tree upright, infill around it with compost, firming down gently until the tree is stable.  
  5. Top-off the compost with a layer of mulch.  
  6. Water the maple thoroughly.

Care of your Japanese maple

Site your maple in a sheltered, semi-shaded spot.  Direct sunlight can be rather harsh and will cause leaf scorch, as can dry winds.  It’s important to keep your maple well-watered but not absolutely soaked.  The tree’s roots are vulnerable to frost damage, so wrap the container in bubble-wrap during the winter months.

Over time, compost loses its nutrients and you’ll need to bolster what it offers by feeding your tree.  Give the tree a feed with a slow-release fertiliser in the spring or early summer as the growing season begins. 

Maples are slow-growing, but you will need to re-pot your tree into a larger container every couple of years to keep it healthy.  Choose either the autumn or very early spring for this job, when the plant is ‘resting’.  Disturbance during the growing season can harm the plant.

You’ll need to prune your Japanese maple annually to keep it healthy and to encourage it to grow into a nice shape.  The best time of year for this job is during the winter months when the plant is dormant.  If you prune the tree during the growing season, it will ‘bleed’ sap, and this can damage it or allow disease to enter.

Maples naturally grow into a graceful, attractive shape, so keep pruning to a minimum.  All you really need to do is remove any crossing shoots or dead branches at the base where they join the trunk.

In conclusion

Japanese maples make lovely ornamental trees to grow in containers.  Follow the guidelines above to care for your tree, and contact your local wholesale nursery if you need any further advice.