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Northern Gardening: More tips for growing trees

Many mistakes are made when the tree is planted, but often the problems do not appear until later. It is important to know that tree roots grow outward, like the spokes of a wheel, rather than down.
Northern Gardening
A diagram showing proper tree-girdling techniques.

Many mistakes are made when the tree is planted, but often the problems do not appear until later.

It is important to know that tree roots grow outward, like the spokes of a wheel, rather than down. This allows the roots to gather water and nutrients from a larger area, and anchors the tree In all directions.

Tree roots also need air to thrive. Most of a tree’s roots grow no deeper than 18 inches.

When planting a potted tree the hole should be no deeper than the pot, but at least twice as wide as the diametre of the pot. If the roots are wound around they must be freed from the root ball and spread outward.

The tree should be planted no deeper than the level it was at in the pot – planted too deep, the roots will not get enough air. Remember that the soil will settle and you do not want the trunk of the tree in a depression where water can collect and cause the bark at the soil level to rot.

Plant the tree where the soil has not been compacted by heavy equipment. If the soil is amended in the planting hole, mix the amended soil with the soil from the hole and rough up the sides of the planting hole. This will encourage the roots to grow outward beyond the planting hole.

Remove any ropes, tags or tape. As the trunk and branches grow in diameter any restricting attachments can prevent water and nutrients from flowing beyond the restriction, killing that part of the tree.

Any supporting sticks attached to the tree should be removed. They are not stakes. If the tree is large or in a windy location, stake on the windward side with the stake beyond the root ball.

Otherwise both the stake and the tree will rock the root ball in a wind. Attach the trunk to the stake using a soft material on the trunk and allowing some movement of the tree in a wind.

Once planted do not expect the tree to fend for itself. It will need a deep watering every seven to ten days for the first two years. Do not allow grass to grow up to the trunk.

Grass can deprive the tree roots of water and nutrients, and grass trimmers can damage the bark, allowing disease and insects to enter the tree.

Use lawn edging and mulch, or a tree matt to keep grass away, but do not allow mulch against the trunk. That can encourage rot. In winter protect the trunk with tree wrap to prevent sun scald as well as rodents eating the bark
and girdling the tree, thus killing it.

Horticulturalist Mary Wright has lived in Denare Beach for over 20 years.