At this time of the year, many trees are covered with their fruit such as the horse chestnut bearing the ‘conkers’ so loved by children and oak trees with their acorns (the ‘haycorns’ so loved by Piglet!). We thought this might be a good excuse to look at how these acorns do indeed grow into mighty oaks from which one of the best hardwoods in the world is derived.
Acorns are harvested in early autumn and are placed in damp vermiculite or peat mix in a refrigerated environment for around 45 days. Those that sprout are then placed, root-side down, in a small pot filled with soil. After carefully nurturing, the seedlings are transplanted outside when they are around 10-15 centimetres tall. These are then managed until they reach a height of between 75 and 125 centimetres when they are passed on to the forester for planting.
On average, one needs to plant around 1,000 seedlings of this size per acre. Not all of these will survive and it is prudent to protect these from natural predators such as deer. Competing shrubs, trees, ferns and weeds must also be kept under control.
As the trees grow, it will be necessary to thin them out to avoid them becoming stunted through lack of sunlight. There are number of recommended ‘regeneration’ practices. Also, the trees will require pruning to ensure that they grow into the right shape for harvesting. Ideally the lower 7 metres of a tree should be straight and without limbs.
The oak is ready for harvesting once the tree reaches the right size, measured by the diameter of the trunk at around 1.5 metres from the ground. The ‘right size’ varies according to the ultimate use of the wood: ‘saw-log’ oaks need to be straight for 3 metres with a minimum of 30 cm. diameter at the small end of the log but larger logs have an increased value.
White oaks grow to 3 to 5 metres in a span of 10 to 12 years. Southern red oaks grow much faster reaching heights of 20-25 metres in 20 years. Good foresters will carefully select the trees for harvesting, leaving others to mature and seed. This way the forest can be maintained naturally.
DJ Newman Joinery only uses wood from sustainable forests. And whilst these trees are growing, they are absorbing carbon dioxide and generating oxygen to help reduce global warming. All of which shows that the use of wood as a material is environmentally responsible!