Thoroughly grounded
THE major function of roots is to anchor the plant to the ground and to reach water and nutrients. From the moment a seed germinates or a cutting takes, roots are growing and need care to ensure they remain strong and healthy. When buying container plants check to see they are well established but not rootbound. When planting, create a spacious planting hole to allow the roots to establish well.
Generally going unnoticed and unseen, root health and growth is strongly influenced by soil conditions. To ensure the success of your plants, consider what is going on underground.
Most plants need soil that is moist but well drained. If soil is continuously waterlogged, it becomes anaerobic and roots can literally drown. Some plants, such as New Zealand forest tree kahikatea tolerate varying degrees of waterlogging. However, the feeding roots need access to aerated soils. To achieve this, kahikatea roots grow in the less waterlogged soils at the surface, allowing them to breathe and absorb nutrients.
In a forest community they can be heavily intertwined, which also provides the extra strength needed to keep tall trees upright. The root system of the largest trees must be strong enough to support massive aboveground weight buffeted by winds, rain and even snow. One of the giant redwoods,
Sequioadendron giganteum in Dunedin Botanic Garden, just above the rock garden, is well over 100 years old. The visual result is the tree’s trunk and foliage is enhanced by an incredible display of exposed roots growing on the cutting above the gravel driveway.