Columnar or Fastigiate trees
To the botanist, the word fastigiate means ‘with parallel, erect, clustered branches’. It has become more widely used in a more generalized sense for trees with narrow crowns. All those mentioned are derived from natural sports and do not come true from seed (if that is produced). They are propagated as cultivars. They generally need careful pruning when young to ensure the necessary erect growth.
Their placing needs great care, as they inevitably have an unnatural look. Fastigiate conifers accord well when planted in the regular pattern of formal gardens-the use of the true cypress in the great Italian gardens of the Renaissance. Fastigiate trees can be skilfully used, too, for adding a steadying vertical element to a steeply sloping site. The planting of a ‘pair one on either side of the introduction to a vista can be very effective. Some of the less erect-growing are excellent for planting in narrow roads, or, for example, at thecentere of a lawn where space is limited.
ACER SACCHARINUM PYRAMIDALE An upright form of the silver maple, useful for street planting.
BETULA PENDULA FASTIGIATA This is an erect, slow-growing form of the common birch, resembling an erect besom.
CARPINUS BETULUS FASTIGIATA This is a valuable pyramidal rather than truly fastigiate cultivar of the hornbeam.
CRATAEGUS MONOGYNA STRICTA This has a narrow, erect-growing crown.
FAGUS SYLVATICA FASTIGIATA
The Dawyck beech is a good erect tree.
LABURNUM ANAGYROIDES PYRAMIDALIS This is an upright laburnum.
LIRIODENDRON TULIPIFERA FASTIGIATUM
A narrow-growing form of the tulip tree.
MALUS HUPEHENSIS ROBUSTA This has large white flowers and fairly erect growth. M. prunifolia fastigiata,the fastigiate Siberian crab.
POPULUSRead more on backyardgardener.com