Field Guide for Watering Newly-Planted Trees
Our Urban Trees are incredibly important to us, they provide shade, lower temperatures, intercept airborne pollutants, reduce runoff, improve our mental health, increase our property values, and more. They also represent a significant investment, when you add the costs of planning and design, public consultation, civil works, tree costs etc. together. However, all our expectations, and all the potential benefits, come to nothing, along with a significant waste of money, if we don’t look after our new Urban Trees, properly, throughout establishment: and the single most important thing, during establishment, is correct watering.
If you are not committed to looking after your newly planted trees well, throughout their establishment phase, there is little point planting them.
The following (downloadable) table gives suggested water application rates, frequency, and duration based on the best information available. Actual water needs will vary according to time of year the trees are planted, site conditions, species etc. These suggested rates are a guide only. Monitor the trees in your projects and vary as needed.
All recommendations assume that the water is applied slowly, directly, and effectively to the rootball (see our articles on Watering Newly Planted Trees and Make Sure Your New Trees Thrive).
Suggested rates are less than ideal. They are intended to be achievable while, hopefully, still effective. Please use them as a base rate, rather than something to strive for.
These recommendations are ‘general’. Less water may be required for drought tolerant species, more for species with high water demands.
Watering timeframes have been broken down into two parts, “Required” and “Recommended”. Treat the Required timeframes as being non-negotiable and strive to continue watering for the Recommended periods shown.
To encourage lateral root development, when watering larger stock for extended periods of time, make sure that the frequency of watering decreases, the amount per application increases, as does the diameter of the area watered, over time. (See “Watering Newly Planted Trees Part 2”)
Monitor the irrigation regularly – especially in heavy clay soils where poor drainage can lead to waterlogging.
For more information and explanation that informed the preparation of this table see ‘Watering Newly Planted Trees’.