The bald cypress prefers very wet, swampy soils. Riverbanks, lake floodplains, wet depressions. They often grow in pure, almost circular, stands; viewed on the horizon, these stands have a peculiar dome shape, with shorter, almost stunted trees growing around the edges and trees gradually growing taller toward the center. As a landscape tree it grows well in relatively dry soils.
The leaves of the bald cypress are tiny needles, grown in 2 rows along slender greenish twigs:
It is deciduous, although the dried, brown leaves often cling to the tree well into the winter.
A close relative is Pond Cypress (T. ascendans). Similar to Baldcypress in that the trunk is perfectly straight 50 to 60 feet tall, Pond cypress has a narrower crown, is smaller, and has a more open habit. It is found along the edges of streams and around the edge of swampy ground where water is standing; whereas Bald cypress is usually found along stream banks. The bright green, awl-shaped leaves are arranged in an upright row formation along the branches when young, giving a somewhat stiffer and more upright appearance than Bald cypress. The leaves turn an attractive light brown in fall before dropping but the bare branches and light brown, ridged bark provide much landscape interest during the winter. The trunk grows unusually thick toward the base, even on young trees. This is thought to provide support for the tree in its wet habitat. The small seeds are used by some birds and squirrels.
Lighting: Full sun.
Temperature: Zone 5B through 9. The range of the bald cypress includes southern Delaware to south Florida, west to Texas and north to southeast Oklahoma, southwest Indiana, and southern Illinois.
Watering: Watering must be done daily, year round, in the south. The pots may be kept submerged almost to the rim during the summer.
Feeding: Use a fertilizer that is well balanced such as Peters 10-10-10 at near full strength. Weekly in spring and early summer, every 2 weeks in late summer and fall until leaves start to turn brown. None over winter.
Pruning and wiring: The bald cypress lends itself to formal upright, informal upright, slanting, literati, twin-trunk and group styles.
In nature, a mature bald cypress growing in the open will have a long, limbless trunk, capped with a cluster of horizontal-to-drooping limbs and a very flat top.
The formal upright probably should take this shape. A younger tree in nature will have limbs growing lower on the trunk, and most will be angling upward. The informal upright might consider this aspect.
In far south Florida, Everglades cypress (most of them "pond cypress") are shorter, and more scraggly; the literati style would suite these admirably. Branches tend to grow the entire length of the trunk -- starting almost at the ground.
Groups of more than 5 or 7 trees might want to emulate the cypress dome habitat that is so natural to them in the Southeast.
That's not a good representation, but the idea is a rounded dome rising out of a flat horizon. The trees along the edges are usually squat and with many leafless branches. The ones toward the center are the flat-topped mature trees that are so typical of the cypress.
These trees are fast growing, and wires will damage the bark if they are not watched closely. Alternatively branches may be tied town using a soft raffia twine, tied near the end of the branch to be pulled down, then tie the other end to the base of the tree trunk, to the pot, or to something else (sometimes the base of the branch immediately below). If the branch to be pulled down is thick, you can make a V-shaped incision at the underside of the limb where it joins the trunk. The V will close when the branch is pulled down, and the wound soon knits.
Shape the foliage by pinching back new growth. Let a branch grow for a season if you want to thicken it, then cut it back the following spring. New growth will sprout at the site of your most recent pruning. Twigs sprout at sharp, acute angles, so it is not difficult to develop a gnarled-looking branch (e.g. /\/\/\/\/\/). You can prune throughout the summer, then shape in the fall just before dormancy. Leaves tend to sprout right out from the trunk. Some will develop into a branch if you let them; others are just leaves. In most cases, these should be plucked off.
Developing cypress "knees." There's still considerable debate over what these knees are "for" in nature, but they are a distinctive feature of bald cypress. You should try to develop at least one "knee" in your mature trees. They are easily developed by going up to 3 years without repotting or root pruning. By then, roots will be jammed into the pot; many will have bent almost double. If you carefully bring one of these doubled bends (one that occurs quite near the base of the tree, or can be brought in closer) to the surface and let it protrude through the moss cover, you will have what is to all intents a knee. These should thicken and develop well over subsequent years.
Propagation: Cuttings or air layer are easiest.
Repotting: Potting and root pruning should be done in spring, just as little green nubs are showing up on the branches and trunk. If the tree is kept in standing water (see below) root pruning is advised every year -- every 2 years at least. In N. Florida, roots have grown 3 feet in a single year (all in a shallow 12-inch diameter pot).
A heavy soil is best such as a compact mushroom compost. If the tree is not kept in water, a heavy soil is a must since it needs to retain as much moisture as possible. You cannot rot cypress roots!
Since bald cypress' preferred habitat is low, swampy terrain, flat shallow, earth-colored pots are recommended. The outside glaze should be a dull earth-tone. Smooth surfaces are recommended for pots that are kept in water, since it is easier to clean the pot when you bring the tree inside for a brief display.
Pests and diseaes: Pests: None of significance.
Diseases: Twig blight is caused by a weak pathogen and is usually present on dead or dying tissue. When the tree is stressed the fungus can kill branch tips. Dead tips can be pruned off. Do not let dead or diseased branches remain on the tree. Keep trees healthy with regular fertilization.
General information: There are trees 800 to 1000 years old in the Cache River basin in Illinois. Bald cypress has been planted far north of its natural range. There are specimens in Minnesota, Southern Canada, and some 75-year-old trees in New York.