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Tree pit gardening advice

Guidance and advice for residents who would like to grow plants around the trees in Westminster’s streets.

Tree pit preparation

Before planting can start, read the information below about the different surfaces used around tree pits and what to look out for. We've also compiled some tips about the best plant species for a successful project.

Soil surface tree pits

Some tree pits are not covered with surface materials, so are easier to cultivate. Residents are encouraged to use the existing soil in these tree pits, rather than remove it.

Removal of any weeds and carefully tilling the soil will loosen the top surface. If the level of the tree pit is lower than the pavement level, new clean topsoil could be added, carefully working the new soil into the tree pit with hand tools to avoid damage to tree roots.

The final tree pit surface should be at the same height as the surrounding pavement.

Self-binding gravel tree pits

Many tree pits are surfaced with self-binding gravel. If this is removed, it should be disposed of in domestic waste, and backfilled with clean topsoil to match the level of the pavement. Again carefully working the new soil into the tree pit with hand tools, avoiding damage to tree roots.

Asphalt or resin-bound tree pits

Tree pit surfaces such as asphalt or resin-bound gravel are sometimes installed for highway safety reasons, so should not be removed.

Please contact Westminster's Tree Team if community gardening activities are being considered where the tree pits are hard surfaced.

Planting tips

It is important to retain the soil level in the tree pit at the same height as the pavement.  Raising soil levels can lead to stress to or death of trees, and a drop in levels can create a trip hazard.

Raised edging should not be installed around tree pits, as it is also a trip hazard and can cause accidents for pedestrians.

Planting around existing trees which have been in the ground for at least 4 years is not likely to be harmful to them, but planting around new trees is not encouraged, as competition for water and nutrients from other plants can prevent the successful establishment of new trees, and there is also a higher risk of physical damage to their roots.

Landscaping materials such as pots, stones, pebbles, or figurines should not be added into tree pits as they can be used in anti-social behaviour activities.

Published: 10 May 2023

Last updated: 10 May 2023