Bald cypress

Identification and origin

Taxodium distichum belongs to the Cupressaceae family. Its native range covers the eastern and southeastern United States, from Delaware and Maryland down to Florida and Texas, reaching up the Mississippi Valley as far as Illinois and Indiana, as well as much of Mexico and Guatemala. There it fills swamps, bayous and riverbanks, especially on the coastal plains. It is planted as an ornamental tree in Europe, where it has sometimes naturalized.

It is a large tree, 49–69 ft tall and 19.5–29.5 ft wide, but its growth rate is moderate: it takes several decades to reach its mature size. Young trees are pyramidal; with age, the crown spreads out and flattens irregularly, while the base of the trunk flares into fluted buttresses. It ranks among the longest-lived trees in the world.

In summer, you could mistake it for an evergreen conifer. Its flat, soft needles, 0–1 in long, are arranged in two rows along slender twigs, which gives the foliage a feathery look. The foliage is yellow-green when the buds break, fairly late in spring, then soft green through the summer, and it turns russet, orange or cinnamon brown in fall. The small twigs then drop along with their needles, and the tree spends the winter bare.

The fibrous bark, reddish brown to light gray, peels off in long, narrow strips. Male and female flowers grow on the same tree: the male flowers hang in clusters in spring, and the female cones are wrinkled balls 1–1 in across, green at first and brown when ripe. In waterlogged soil or at the water’s edge, the roots produce the famous “knees,” cone-shaped woody growths that rise out of the soil or water and are thought to help the roots get air.

It is often confused with the dawn redwood (Metasequoia glyptostroboides), another deciduous conifer, whose needles are opposite rather than alternate. Among the cultivars: ‘Pévé Minaret’, a dwarf shrub about 8 ft tall with fine foliage; ‘Cascade Falls’, compact and weeping; and ‘Shawnee Brave’, narrowly pyramidal.

Light

Bald cypress thrives in full sun, with at least six hours of direct sunlight a day, and it tolerates partial shade. The more light it gets, the denser its foliage and the stronger its fall color. It stands up well to wind, which makes it a good specimen tree for large, exposed gardens.

Watering

Few conifers are as tolerant of excess water: it handles standing water and long periods of flooding, and it thrives at the edge of ponds. Even so, it does perfectly well in moist, well-drained soil. Its drought tolerance is only moderate, though: water a young tree deeply as soon as the soil dries out further down, especially in hot weather.

In a tub or pot, it gets very thirsty in summer: check the potting mix every day and water as soon as the surface dries, until water runs out of the bottom. If a pot dries out too fast, a shallow saucer filled with water makes a handy reservoir. In winter, the bare tree drinks much less, but the root ball should never dry out completely.

Potting mix

In the ground, it accepts clay, silt, sand and soils rich in organic matter. It clearly prefers acidic soil, though: in alkaline, chalky ground with a high pH, its needles turn yellow from chlorosis. In a container, use a lime-free mix that holds moisture while still letting air through.

Temperature

Bald cypress is very hardy in the ground: it withstands the harshest continental winters, below -4 °F, and does well from the northern edge of cold temperate regions down to mild climates. It also enjoys the hot summers of its native range.

In a pot, things are different: the roots are poorly protected and barely tolerate frost. In regions with cold winters, shelter the container, bury it in the ground or move it to a cold, bright shelter, while still letting the tree stay dormant.

Repotting

It transplants easily, whether container-grown or balled. In the ground, plant it in moist soil, preferably acidic, and water regularly during the first year.

In a pot, its roots grow vigorously and thicken quickly: repot a young tree about every two years, pruning the roots as you go, and do it right away if the root ball starts lifting out of the container. An older tree can wait three to five years. The roots stay soft enough to be pruned without any trouble.

Pruning

In the ground, no pruning is needed: the tree develops its conical shape on its own, then its flattened crown with age. Just remove any dead or damaged wood.

Grown as bonsai, it responds very well to pruning, producing plenty of buds on the trunk and branches. The techniques specific to this kind of growing are covered in detail in the bald cypress bonsai guide.

Propagation

Seed is the usual method for the species, and it succeeds fairly easily. Cultivars are propagated from cuttings so they keep their traits. Cuttings actually work fairly well for the species itself, too.

Common problems

Bald cypress is generally tough and rarely attacked, especially when it is growing vigorously: weakened trees are the most vulnerable. A single symptom can have several causes, so look over the whole tree before you act.

• Yellow needles in summer: often chlorosis caused by soil that is too alkaline; a long lack of water can also be to blame.
• Dull, speckled needles with fine webbing: mites, including the two-spotted spider mite, the main enemy in hot, dry weather; gall mites can also distort the twigs.
• Twigs drying out: a twig disease (dieback) sometimes shows up.
• Small hanging cases: bagworms; caterpillars of moths specific to cypress also turn up.
• General decline: armillaria root rot can attack the tree wherever this fungus is present.

Keep in mind that needles and small twigs dropping in fall is normal; it is not a sign of decline.

The tree is also quite resistant to fire, pollution and wind, moderately tolerant of salt, and deer tend to leave it alone for the most part.

Toxicity

No toxicity has been reported: bald cypress does not appear among the plants that veterinary references list as toxic to dogs and cats. Still, keep children and pets from chewing on its needles or cones.