atb,
Trees on heathland courses are great, just don't ask me to curve my ball around them! Walton Heath is a great example, they have some beautiful specimen trees but they are all outside the corridors of play, mainly behind greens providing beauty without intruding. When you think about it planting trees within playing corridors is very risky as they tend too grow! At just what stage are they perfect, not too long I would imagine.