Tree planting scheme: what it is and when it is justified

A tree planting scheme defines where to plant, which species and forms to use, what volume of soil to provide and how to manage the trees after establishment.

It is justified in streets, parks, developments, industrial sites, hotels and properties where trees play a structural role.

Even in a smaller intervention, the same principles help to avoid isolated choices that conflict with services, buildings or maintenance.

The work starts with the existing trees and the spaces without canopy.

Species, size, condition, approximate age, conflicts and value are recorded.

Soil, water, heat, wind, circulation and infrastructure are also analysed.

The absence of trees in a street may be the result of a lack of space and not simply an empty opportunity. The scheme needs to understand what must change to make planting viable.

Shade, comfort, landscape continuity, biodiversity, visual screening or phased replacement are possible objectives.

They should be located and prioritised.

A tree to mark an entrance is chosen differently from an avenue planting for shade or an industrial screening belt.

The objective guides size, crown, leaf persistence and spacing.

The width of the street, façades, balconies, lighting, cables and circulation determine the volume available.

The future crown is shown, and not just the size at planting.

Where space is narrow, a columnar cultivar can help, but it still grows in height and width.

Pruning should not be the permanent mechanism for making a large tree fit.

Roots compete with foundations, paving bases and services.

The scheme defines the volume, continuity and quality of the soil. Isolated tree pits can be linked or supplemented by systems under the paving.

Drainage and irrigation are integrated.

Without soil, the selected species will not reach the crown that justified the scheme.

Climate, microclimate, texture, pH, water, wind, salt and maintenance all enter into the choice.

Fruit, thorns, allergies, invasive potential and structural behaviour are also assessed, depending on the use.

The cultivar can change size and form. The specification should be complete.

Proven species are combined with diversity and, where appropriate, controlled trials of new selections.

Depending on one species or family increases plant-health and climate risk.

Diversity can be organised by streets, stretches or landscape units.

It does not mean losing identity. Forms, rhythms and heights can maintain coherence.

The scheme also considers ages, so that the whole tree stock does not grow old at the same time.

The trees should have a prepared root system and a compatible trunk, crown and form.

Girth and height are not enough.

In large programmes, early selection makes it possible to follow batches, define crown heights and reserve material.

Nursery availability should be known before finalising an impossible specification.

Distances respond to size, function and infrastructure.

Junctions, pedestrian crossings, lighting and accessibility call for set-back distances.

Orientation can matter for asymmetrical specimens.

The plan also defines the planting hole, staking and protection during the works.

Replacing many trees at once can eliminate shade and identity.

A phased plan keeps part of the canopy while new specimens establish.

The phases take account of age, risk and planned works.

In new developments, the trees can go in early to gain growing time.

The scheme includes water for the first years.

A drought-tolerant species does not do without establishment.

Irrigation zones, flow rates, access and responsibility are defined.

Early mortality should be monitored and the causes recorded before replacing.

The crown is guided towards its use without severe cuts.

Temporary branches help the trunk and are removed gradually.

Formative work continues after planting and needs skilled staff and a calendar.

A tree that arrives with a suitable structure requires less correction.

The scheme does not end with planting.

Each tree can be given a code, date, species and history.

Inspections, watering, pruning and replacement update the inventory.

The data make it possible to know which species work in each condition and to improve future decisions.

It is especially important where there are many trees, public space, long-term investment or conflicts with infrastructure.

It is also justified when existing trees are ageing or when the climate is changing performance.

On a small property, a simplified version can guide the structural trees and the phasing.

A tree planting scheme treats each tree as part of a future network, and not as a unit planted with no relation to the others.

• The right tree for the right street
• How much soil does an urban tree need
• Species diversity

1. Plano Municipal de Arborização do Porto.
2. Trees for Life: Master Plan for Barcelona’s Trees 2017–2037.
3. London Urban Forest Plan.
4. European Arboricultural Standards. European Tree Planting Standard.