October's plant of the month: swamp cypress

A stand-out conifer with an added bonus of great autumn colour

Taxodium-Sandstone-Path-1.jpgThe name Harlow Carr means ‘bog at the bottom of Harlow Hill’. What better plant to talk about in this context than the swamp cypress, Taxodium distichum? Native to the southeastern United States, swamp cypress is perfectly adapted to having permanently soggy feet.

In the wild it can be seen populating lowland river flood plains and swamps, where it forms extensive forests seasonally inundated with river sediment. To overcome these oxygen-free - anaerobic - conditions, Taxodium has specially adapted pneumatophores (knees). These red-brown knees arise from the roots and radiate out from the base of the tree trunk allowing oxygenated air to enter the plant's root system. When planted on higher ground away from water, these 'knees' do not develop.

In spring and summer this striking conifer certainly stands out against its darker green broadleaf neighbours. It has pleasing feathery light green foliage, the effect created by its millions of delicately curved needles.

The swamp cypress, like any other conifer, forms cones and sprouts needles. However, unlike traditional evergreen conifers, from early October onwards its canopy transitions from light green to a rustic brown, red and orange combination. Despite not possessing the bright and vibrant scarlet reds or rich butter yellows favoured by many other deciduous trees, Taxodium stands out in a more muted way. Soon after, the tree drops all its foliage, carpeting the ground in rusty reddish-brown needles.

Taxodium is one of only of only 20 deciduous conifers species, which include Chinese swamp cypress (Glyptostrobus pensilis), dawn redwood (Metasequoia glyptostroboides), golden larch (Pseudolarix amabilis), two species of swamp cypress (Taxodium) and 15 species of larch (Larix species).

Reaching an impressive 30 metres or more when mature, this tree is best planted in a larger garden or amenity landscape, planted around an ornamental lake or pond. It is very tolerant of a wide range of soil conditions, requires no pruning and is pest and disease free.

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