As arborists we are very sensitive to how the weather impacts on trees.
The late spring has been very benefical for trees, especially newly planted or transplanted trees.
Whilst we like nothing more that sunny weekends so that we can go out and about with our families and enjoy our gardens, but we really prefer cool, wet summers.
Trees get stressed by hot temperatures, especially when combined with dry winds and prevailing dry weather. This can be multiplied when planted around hard surfaces / buildings (reflected heat) or when there is insufficent rooting area (unable to access moisture in the ground).
Newly planted / transplanted trees have to rely on humans to water them, whilst they establish (extend their root system to that of a normal tree). Often the will, resources and competence are not available to these trees.
This lack of watering can have devasting results to these 'new' trees. When there are drought conditions, especially when the water table drops, even established trees can suffer.
Mulching of both newly planted/transplanted trees can greatly assist trees, by retaining moisture within the soil, reducing competition from weeds and grass (which often have root systems that can extend down as far as trees), slowly adding organic matter to the soil but most importantly increasing Mycorrhizal activity by upto 15 times over grass.