Bald Cypress on Riverfront Property
Bald cypress hold the banks of Hill Country rivers together, and on riverfront property the best care is usually the least: leave healthy cypress and their roots alone, keep heavy equipment off the bank, trim only what threatens a house or deck, and watch older flood-damaged trees for slow decline.
Why They Matter So Much Here
Along the Blanco River, Cypress Creek and the San Marcos River, bald cypress are the trees that make the landscape. Their wide, spreading roots grip the banks like reinforcement. They shade the water, which keeps it cooler for fish and other river life. Some are very old: in 2011, the Guadalupe–Blanco River Authority dated one cypress on the Blanco back to at least 1426.
They're built for water. Bald cypress tolerate flooding and wet soil, and near the water they often grow "knees," woody bumps that rise up from the roots.
What the 2015 Flood Showed
On Memorial Day weekend in 2015, the Blanco River rose to a crest of just over 41 feet in Wimberley, far above its 13-foot flood stage. The Texas A&M Forest Service estimated close to 12,000 trees between Blanco and San Marcos were damaged or destroyed, with bald cypress the most common. Some of those trees were centuries old.
Several lessons from the cleanup still apply to anyone with riverfront trees:
Don't rush the cleanup. Forest Service experts warned that hurried removal of downed and damaged cypress caused more harm, since roots of trees that looked dead could still be alive and push new growth.
Keep heavy equipment off soaked banks. Machinery on waterlogged riverbank soil crushes and tears the roots of surviving trees.
Leave downed wood below the bank. Local master naturalists advised leaving fallen trees along the river where they landed. They hold soil in place and give young plants shelter while the bank recovers.
Replanting is slow. Many young cypress were planted after the flood, but the Forest Service expected only around half to survive, which means decades before the banks look the way they did.
Flood Damage Shows Up Late
A cypress that survived a big flood can look fine for a while, then decline. Signs worth watching in older riverside trees:
- Thinning crown, or dead branches at the top
- Bark torn away low on the trunk where debris hit it
- Roots exposed and undercut on the river side
- A new lean toward the water
- Fungal growth or soft wood at the base
A tree showing these signs that stands over a house, cabin, deck or drive needs a closer look. One leaning over open riverbank, away from anything it could hit, is often best left standing or allowed to fall and stay where it lands.
Brown in November Isn't Dead
Bald cypress is a conifer, but it drops its needles every fall. The needles turn rusty orange or brown, then fall, and the tree stands bare through winter. New owners sometimes panic. If the tree leafs out again in spring, it's fine.
Trimming Cypress Near Structures
Cypress limbs over decks, roofs and docks can be reduced cleanly. A few guidelines:
- Trim in late fall or winter, during dormancy.
- Take only what's needed to clear the structure; don't strip the lower trunk or thin heavily.
- Don't top cypress. It ruins the tree's form and invites decay.
- Leave the knees. Cutting them can damage the root system and open it to rot.
Removing a Cypress
Removal is reasonable when a cypress is dead or failing over a structure, or has been damaged beyond recovery near where people gather. Even then, cutting the trunk and leaving the stump and roots in place is usually better for the bank than pulling or grinding the root system. Check with any river authority or local rules that apply to your stretch before major work along the water.
Other Trees Along the Water
Bald cypress share the banks with American sycamore, pecan, cedar elm and black willow. Sycamores and willows grow fast and break more easily in floods and wind, so they tend to need more attention near structures. Pecans on river bottoms grow very large and drop limbs as they age. The same rule applies to all of them: work near the house, leave the bank alone where you can.
Living With Riverfront Trees
The banks that held best in past floods were the ones with native trees, shrubs and grasses, not mowed lawn to the water's edge. Leaving a buffer of native plants along the bank, along with the cypress, sycamores and pecans that grow there, protects both the river and your property.
More about which parts of town are covered is on the San Marcos service area page.