Summary Sessile oak 1 + 1 transplants were grown for 4 years in a weed-free environment at 1 X 1 m spacing on a fertile sheltered site. Four experiment treatments were imposed: control with no treeshelter and treeshelters of heights 0.6 m, 1.2 m and 1.8 m. Treatments had no significant effect on tree survival. Taller shelters produced taller, lower diameter trees of increasingly low dry root weight. The root:shoot ratio was 0.675 in control trees but declined to 0.291 in 1.8-m shelters. Trees from 0.6-m and 1.2-m shelters (mean heights 152 m and 206 m respectively) supported themselves unaided after removal of the stake and treeshelter. The trees from 1.8-m shelters of mean height 234 cm at age four collapsed completely when support was removed.