Lime, Linden
Species of ornamental lime trees are growing in popularity as freestanding specimen trees in our parks and gardens and their flowers are especially attractive to bees as anyone visiting the Hampton Court flower show will have seen when sitting under the young lime avenues. The leaf shapes and flowering times of species of limes can be very different and arboretums are trying out new species, some only recently available in the UK, for themselves.
Lime species are all fully hardy and will tolerate both acid and alkaline soils. They have, in the main, silver-grey bark which becomes fissured with age. The flowers are creamy-white or yellow in slender cymes with long stalks. The flower stalks have membranous pale yellow or green bracts on their upper surfaces. These are followed by rounded, dry, nut-like fruits in the autumn.
Many limes produce thickets of shoots from the base of their trunks. Not just from the rootstocks which some of the rarer grafted species will be; but also from the tree itself. These need to be cut off and removed annually to avoid diverting energy to the growing tree and because they are unsightly in a parkland context. Even in full maturity dense basal shoots shorten the life of the tree and obscure the bark.
Before sowing lime seed you should stratify or chill them for three to five months before sowing either in the fridge or, in colder areas, in the cold ground itself.
T. cordata, the small leaved lime, is a columnar tree to 50ft with cymes of up to 10 individual pale-yellow flowers in midsummer.
T. cordata ‘Winter Orange’ is an outstanding ornamental tree with red buds and pronounced orange twigs and shoots in winter which are clearly visible from a considerable distance. It has ivory scented flowers and butter yellow autumn colour. The new growth colours best in immaturity so you may decide to prune and shape young trees to encourage more.
T. x europa, the common lime, grows to around 120ft with a spread of 50, has cymes of pale-yellow flowers in June/July and is commonly grown in avenues.
T. henryana has huge obovate leaves with pronounced bristles or teeth. Unusually, it flowers in August or September, and can make a tremendous show then, when so few other trees are actually flowering. Our tree is around 20ft after as many years.
T. kuisiana is a small tree which, with us, is absolutely plastered with small heavily scented greenish-yellow flowers in August. You can see the pictures of it performing below.
T. mongolica, the Mongolian lime, grows to about 40ft as a rounded small tree in maturity. The undersides of the leaves are blue-green and up to 30 flowers are produced on each cyme.
T. mongolica ‘Harvest Gold’ has startling yellow new leaves which gradually fade to green. The yellow autumn colours are superb too.
T. oliveri grows to around 50ft with pendant branches and a spreading habit. The leaves are a hairy-white underneath, and the hanging cymes have six to ten pale yellow flowers in June to July. This is a little-known species but is looking good at Caerhays as a 10- to 12-year-old young tree.
