#TeachingTuesday: Bald Cypress
Bald cypress (Taxodium distichum) is a deciduous gymnosperm tree native to North Carolina and the southeastern US. It naturally grows in swampy areas, and thrives in standing water. Because it can survive in these conditions, it also grows well in other poorly drained soils, like the clay soils around Chapel Hill and Durham. It makes a nice specimen tree in a lawn area or as part of a mixed tree and shrub border.
There are two main unusual features of bald cypress. The first one is that it is a deciduous gymnosperm, meaning it has needle-like leaves and cones similar to pine, spruce, and fir trees which are all evergreen, but it drops its leaves in the winter. The second unusual feature is that bald cypress trees often grow stumpy “knees” in the area surrounding the trunk. These occur most often in the wild, but sometimes grow in the landscape as well. Botanists’ theory is that these growths help with oxygen exchange for the roots.
Bald cypress trees are very low maintenance. They rarely have pest or disease issues. Because they are used to growing in swampy soils with very poor nutrition, they rarely need fertilizer. Pruning is only necessary if a branch becomes diseased or broken, or if some corrective pruning is needed on a very young tree. Bald cypresses should never be “topped” or cut back, as this will ruin the beautiful natural form of the trees. In the fall, the dropped leaves and cones may need to be raked and removed from lawn areas, or they can be left in place to decompose if the tree is in a natural area. Be careful mowing around them if you spot any knees growing!
- The leaves are light green and feathery, with tiny flat leaflets in opposite pairs along the midrib.
- The leaves have a reddish bronze fall color.
- The cones look like green golf balls with a textured pattern on them.
- The trunk of a mature tree flares out at the base.