Planted trees average 2.9m intertree distance, but GoatGuy's right, they overdo it the first time so they don't have to go back and spend more money. They usually only need a tree every 3.4m to achieve freegrowing, even 3.8m in the IDF. However, there are lots of different issues affecting trees that can prevent them from achieving freegrowing; diseases, injuries, weather, poor planting, brush competition... It's wise to plant more than you need.