Staking mature trees: systems, aims and common mistakes

Staking keeps the rootball stable while the roots expand into the surrounding soil. The aim is not to prevent all movement of the crown. It is to stop the base from rotating, lifting or shifting with every spell of wind.

The system depends on the size, the form of the crown, the species, whether the foliage is evergreen and the exposure. There is no rigid limit that suits every tree.

In Diaplant’s practice, double staking is common up to a girth of 20–25 cm, triple staking may be used for larger sizes and, as a guide, trees from 40–50 cm upwards may require oblique anchoring with steel cables. These values are references and not absolute rules.

A newly planted tree does not yet have roots in the new soil. When the crown moves, the forces reach the rootball.

Slight movement of the branches is part of adaptation. The problem arises when the root mass opens up space in the soil, breaks new roots or changes the level.

Staking should control the base with the smallest system able to do that job.

Two treated pine stakes can be placed on opposite sides and linked by a crossbar or straps.

The system suits trees of moderate size when the wind and the crown do not call for greater restraint.

The stakes sit outside the rootball so as not to damage roots. The position is defined before backfilling is complete.

The ties should be wide, flexible and kept off the bark by suitable protection.

Three stakes distribute forces in several directions and are useful for larger trees or exposed sites.

The system takes up more space and has a greater visual presence. Its position needs to respect circulation and maintenance.

Badly aligned triple staking can still allow rotation. The geometry and the tension of the ties matter more than the number of parts.

On large specimens, steel cables or equivalent systems can link the tree to anchors in the ground.

The layout takes account of wind direction and the crown’s centre of force. Cables need marking and protection so that they do not create a trip hazard.

Contact with the trunk is made through straps and materials that spread the pressure. Cable is never wound directly round the bark.

The tension is reviewed after settlement and after spells of wind.

Underground kits stabilise the rootball with no visible elements above the ground.

They are useful in projects with an immediate finish, in circulation areas and on trees or multi-stems where stakes interfere with the form.

The system requires a base able to take the anchors and an installation compatible with the mesh of the rootball.

It can be used on its own in suitable conditions or to reinforce above-ground staking.

An evergreen tree presents leaf area to the wind during winter, precisely when many plantings are carried out.

The force can be greater than on a leafless deciduous tree of the same size. Crown density and form should be assessed.

Multi-stems and leaning trees also create different centres of force and may require specific anchoring.

Placing the strap very high reduces movement, but increases dependence and can prevent the tree from responding mechanically.

A tie that is too low may not control the base on large crowns.

The height is chosen to stabilise the rootball without immobilising the whole trunk. There is no single measurement.

Narrow straps cut into the bark as the trunk thickens. Hard materials cause friction.

The ties should be visible and accessible for inspection. Closed protections that hide damage are not suitable.

On thin bark, checks are more frequent.

Staking is reviewed after the first watering, because the soil settles. It is also inspected after strong wind and during growth.

The things to look for are excessive slack, constriction, a broken stake, a loose anchor and friction.

Maintenance needs someone responsible. Installing without planning for inspection turns a temporary protection into a risk.

The system is taken away when the roots can stabilise the tree. The time depends on the size, the soil and the growth.

Leaving stakes in place indefinitely limits movement, marks the trunk and can create dependence.

Removal should be decided by checking, and not just by a date, although the plan gives a window for review.

Stakes driven into the rootball, tight straps, unmarked cables and forgotten ties are common problems.

Another mistake is to try to use staking to correct a planting hole that is too loose, a rootball that has broken up or a tree unsuited to the exposure.

Stability begins with preparation and placing. Staking completes that work during the phase when the roots cannot yet do it.

• The technical planting sequence
• How to monitor adaptation
• Planting mature trees

1. European Arboricultural Standards. European Tree Planting Standard.
2. Staking and anchoring procedures used by Diaplant.