Advice
Planting trees at the right level
It
is often assumed that the most vulnerable part of a tree is
the canopy or rootball but the stem collar is highly susceptible
to damage such as physical impact damage from garden machinery
and the slower, less obvious, but often terminal, effects
of planting at the wrong depth.
If the stem collar is submerged in soil the bark is liable to rot (resulting in the gradual death of the tree) and if planted too shallow the roots may become desiccated giving reduced vigour and increased susceptibility to pests and diseases.
Bare-rooted trees should be planted so that the original soil line is slightly above soil level on a slight mound. After the worked soil has settled, the tree should be at the same level it was growing in the nursery field. Avoid forming an inward sloping saucer as the accumulation of excess water and detritus, over time, may result in stem or collar rot.
Check container-grown specimens before planting to ensure that the stem collar is not immersed in deep, damp compost. Remove a couple of centimetres of compost (if necessary) and plant in a slight mound as above.