ovoid to oval acorn, 1.5 - 2.5 cm, groups of 2 to 6
narrow avenues and streets
nutritious and moist
NAKB selection, Boskoop, The Netherlands, late 1970’s
A clone produced vegetatively from Q. robur 'Fastigiata', with rough ascending branches that do not droop. This creates a closed columnar shape that later becomes narrow pyramidal but still remains well closed. Height approx. 10 - 15 m, breadth 3 - 6 m. The trunk usually branches low down and the bark is dark grey and, in old specimens, deeply grooved. Young twigs are reddish-brown. The variable leaves are obovate to elongated oval and a little larger than those of the species. They have 3 to 6 pairs of blunt lobes and emerge brownish-red in the spring. The ovoid acorns are grouped in twos to sixes and are a maximum of one-third enclosed in the cupule. 'Fastigiate Koster' is one of the best columnar oaks. 'Fastigiata Koster' stands up well to hard surfaces, making it an ideal tree for narrow avenues and streets.