NATSPEC

National Building Specification

• Natspec is a system that has been implemented to provide an industry standard for the growing and purchasing of trees which ultimately benefits the end user.
• Whether using trees for a domestic garden or a major commercial project the trees that you purchase must have been grown to a standard which will make a positive long lasting contribution to their environment.
• Natspec trees establish rapidly and continue to grow as a dominant long term part of any landscape.

All of these points will aid in enhancing any design & ensure the integrity of that design.

Natspec defines important characteristics so that the end user who wishes to can measure the quality of what they are buying. These characteristics have been divided into several categories the main two are above ground and below ground.

ABOVE GROUND

Health & vigour

- eg healthy at time of delivery to be able to grow on successfully

Crown balance

- indicator of the structural integrity of the tree/s

- adequate spacing is essential to produce a quality tree

- it is critical to produce a well branched, well balanced tree with good stem taper.

Uniformity of growth

Trees should be grown at a steady rate.

- growth surges associated with over fertilizing or ‘pushing’ a tree on, this can result in leggy growth, poor crown formation & reduced taper.

- stem taper is a measure of a trees ability to support itself above ground. Largely a trees response to physical movement while the tree is growing.

- Trees with unsufficient stem taper will need artificial support.

Pruning history

Ensures Trees are not simply hacked into saleable shape before shipment. For example it is important that the tree has been grown with a clean stem from early in its life rather than the wholesale removal of branches – which can lead to secondary infection due to large wounds, and root and shoot damage and can also detract from the appearance of the tree at planting.

Apical Dominance

Many species best grown with a defined central leader – this helps reduce the risk of splitting later in life, and improves the appearance of the tree at planting and as a mature specimen.

North indicator

Correct orientation of a tree can be important to the success of a tree in its new location. Ensures that the cambium sheltered from the sun in the nursery is not exposed on planting.

BELOW GROUND

The root system of a landscaped tree should have sufficient surface area to be able to take up water and nutrients and be well structured and support the tree indefinitely. There are two key elements that define a quality root system – division and direction.

Division

To achieve a structured division of roots good potting or root pruning is necessary. At Winter Hill we as a grower see root development as part of the growing process and root prune at every stage of potting up.

The ability of a root system to take up nutrients is dependent upon their surface area, which is directly affected by root division. Root division must be progressive to ensure that root development has a strong base.

Direction

Roots grow by extensions from the roots. Therefore if trees are not root pruned at every stage of the growing process and there is confusion as to the direction in which the roots should be growing this will cause problems in years to come. For example a tree can grow well for a few years then die; a young tree with spiraling roots that may only be as thick as hairs at planting, can, if left untreated, eventually strangle the developing root system and cause the tree to fail in the long term.

Taken from Specifying Trees – a guide to assessment of tree quality by Ross Clark (1996)