Watering newly planted trees, shrubs and perennials

New planting needs more water while roots leave the pot-shaped ball. Johgee raises demand for newly planted stock.

Generated 2026-08-23T10:00:00.000Z. Valid until 2027-02-23T10:00:00.000Z. Ruleset facts below must match the Johgee core.

Locked facts

New-planting landscape coefficient is 0.95.
Newly planted stock uses a 1.25 establishment multiplier; establishing stock uses 1.1; established stock uses 1.0.
1 mm over 1 m² equals 1 litre

A plant that went in this season still drinks from a small rootball. The surrounding soil can be moist while the ball is dry. That is why establishment is a separate question on the calculator, and why new planting uses a 0.95 landscape coefficient with a 1.25 multiplier when you mark it newly planted.

RHS advice is to water the rootball slowly, then mulch, rather than damping the leaves. Keep checking for the first growing season, especially in containers or against a south wall.

The numbers are a starting plan. If the rootball is still dry after the suggested litres, give more in a second slow pass. If it is wet, wait. This remains a decision aid.

Sources

RHS watering guidance

This is a decision aid, not a guarantee.