More than half of New Zealand's radiata plantation forests are pruned three times in the first 10 years of life. That makes them unique, and the resulting clear wood highly prized.

Pruning regimes vary, but in general the first prine, or "lift" is done whe trees are 5~6m high and there are two more prunings before the trees reach 8m - always leaving 3~4m of photosynthesising crown.

Radiata trees are pruned to produce knot-free clearwood and create a higher price. But the process is labour-intensive and increase production costs. Threes grow upwards and outwards. If a nail is hammered in 5m up the tree, it will remain at that height from the ground. But it will be progressively covered by new wood as the tree laydown more rungs with each season.

The same applies to pruned branch stubs - they stay at the same height and clearwood coveres them as the tree grows. The bark will retain the pattern of "whirls" fromwhere the branches were pruned, but don't be deceived: there is excellent clearwood firectly below.

The defect "core" in the centre of the pruned is narrow and well covered with high-value clearwood.