Does My Tree Need Fertilizer?

Trees growing in their natural habitat should have access to all of the minerals they need to survive and grow. Anything you can do to mimic that habitat can reduce the need for fertilizer. This may include letting leaves remain on the ground in the fall instead of raking them up. Chances are, though, that despite your best efforts, the need for fertilizer will not be entirely eliminated.

When Should I Fertilize My Tree?
A good time to fertilize trees in most Northern temperate climates is from fall to mid-spring. At these times the tree's roots take the nutrients from the soil and apply them to important health-promoting functions such as root development and disease resistance, rather than simply putting out new growth.

During the growing season, fertilizing can help a tree overcome mineral deficiencies and fight off infections. If you are fertilizing in mid- to late summer, avoid formulations high in nitrogen as this will just promote weak, new growth that may be easily damaged in the winter.

How to Fertilize a Tree

The main reason to fertilize trees and shrubs is to bolster their health so they are better prepared to fight off pests, disease, and environmental stresses. While fertilizer can't solve all of a tree's problems, it will go a long way to give it a fighting chance.
Does My Tree Need Fertilizer?
Trees growing in their natural habitat should have access to all of the minerals they need to survive and grow. Anything you can do to mimic that habitat can reduce the need for fertilizer. This may include letting leaves remain on the ground in the fall instead of raking them up. Chances are, though, that despite your best efforts, the need for fertilizer will not be entirely eliminated.
When Should I Fertilize My Tree?
A good time to fertilize trees in most Northern temperate climates is from fall to mid-spring. At these times the tree's roots take the nutrients from the soil and apply them to important health-promoting functions such as root development and disease resistance, rather than simply putting out new growth.
During the growing season, fertilizing can help a tree overcome mineral deficiencies and fight off infections. If you are fertilizing in mid- to late summer, avoid formulations high in nitrogen as this will just promote weak, new growth that may be easily damaged in the winter.
Where Do I Put The Fertilizer?
The objective of fertilization is to put the nutrients where they will best be taken up by the tree's roots. Therefore, it is necessary to fertilize throughout the entire root system. In general, the roots extend well beyond the outer reach of a tree's branches.
The fertilizer must also be placed underneath the roots of any competing plants such as grass or other ground cover. Spreading granular fertilizer on the lawn might make your grass greener, but it will likely not help your tree.
What Type of Fertilizer Do I Need?
Fertilizers are made up of macronutrients (Nitrogen, Phosphorus, and Potassium) and micronutrients (such as Iron, Magnesium and Manganese). These minerals all have different effects on the growth of a tree and different trees need different formulations. It is important to ensure that you use the right fertilizer for your tree. To find out how to obtain the correct fertilizer for your trees or shrubs

Planting Bare-Rooted Trees

Planting bare-rooted trees is a little different as there is no soil surrounding the roots. Most importantly, the time between purchase and planting is a more critical issue. Plant as soon as possible. When purchasing bare-rooted trees, inspect the roots to ensure that they are moist and have numerous lengths of fine root hairs (healthy). Care should be taken to ensure that the roots are kept moist in the period between purchase and planting. Prune broken or damaged roots but save as much of the root structure as you can.
To plant, first build a cone of earth in the centre of the hole around which to splay the roots. Make sure that when properly seated on this cone the tree is planted so that the ‘trunk flare’ is clearly visible and the ‘crown’, where the roots and top meet, is about two inches above the soil level. This is to allow for natural settling.

Planting Container Trees

Container trees (though subject to greater heat and drying conditions than B and B) can also be stored for a brief period of time after purchase as long as the soil in the container is kept moist and the tree stored in a shady spot. The procedure for planting container trees is similar to that for B & B trees. In the case of metal or plastic containers, remove the container completely. In the case of fibre containers, tear the sides away.
Once carefully removed from the container, check the roots. If they are tightly compressed or ‘potbound’, use your fingers or a blunt instrument (to minimize root tearing) to carefully tease the fine roots away from the tight mass and then spread the roots prior to planting. In the case of extremely woody compacted roots, it may be necessary to use a spade to open up the bottom half of the root system. The root system is then pulled apart or ‘butterflied’ prior to planting. Loosening the root structure in this way is extremely important in the case of container plants. Failure to do so may result in the roots ‘girdling’ and killing the tree. At the very least, the roots will have difficulty expanding beyond the dimensions of the original container. To further assist this, lightly break up even the soil outside the planting zone. This allows roots that quickly move out of the planting zone to be more resilient as they anchor into existing surrounding soil conditions.
Once the tree is seated in the hole, the original soil is then back-filled into the hole to the soil level of the container. Again, remember not to overly compress the back-filled soil especially by tramping it with your feet. Compress gently using your hands instead.

Fast Growing Trees

Planting Balled and Burlapped Trees

Balled and burlapped (B & B) trees, although best planted as soon as possible, can be stored for some time after purchase as long as the ball is kept moist and the tree stored in a shady area. B & B trees should always be lifted by the ball, never by the trunk.

The burlap surrounding the ball of earth and roots should either be cut away completely (mandatory, in the case of synthetic or plastic burlap) or at least pulled back from the top third of the ball (in the case of natural burlap). Any string or twine should also be removed.

Backfill soil (combinations of peat moss, composted manure, topsoil, etc.) is then placed in the hole surrounding the tree just to the height of the ball or slightly lower to allow for some settling.

Be careful not to compress the back fill soil as this may prevent water from reaching the roots and the roots from expanding beyond the ball.

How To Plant Trees

While planting different types of trees differs in the details, all trees eventually end up in a hole. But not any old hole will do.
The most common mistake when planting a tree is a digging hole, which is both too deep and too narrow. Too deep and the roots don’t have access to sufficient oxygen to ensure proper growth. Too narrow and the root structure can’t expand sufficiently to nourish and properly anchor the tree.

As a general rule, trees should be transplanted no deeper than the soil in which they were originally grown. The width of the hole should be at least 3 times the diameter of the root ball or container or the spread of the roots in the case of bare root trees. This will provide the tree with enough worked earth for its root structure to establish itself.

When digging in poorly drained clay soil, it is important to avoid ‘glazing’. Glazing occurs when the sides and bottom of a hole become smoothed forming a barrier, through which water has difficulty passing. To break up the glaze, use a fork to work the bottom and drag the points along the sides of the completed hole. Also, raising the bottom of the hole slightly higher than the surrounding area. This allows water to disperse, reducing the possibility of water pooling in the planting zone.