Trimming the bottom branches of a cedar tree, known as “limbing up,” is a structural pruning method used to reshape the lower canopy. This practice transforms a dense, shrub-like cedar into a conventional tree form with an exposed trunk. Limbing up creates clearance beneath the tree, allowing for easier pedestrian access or the use of lawn mowers. It also achieves a cleaner, more manicured look in a landscape setting.
Defining the Purpose and Optimal Timing
Removing the lower limbs serves practical purposes beyond aesthetics, including enhancing the tree’s health. Raising the canopy improves air circulation, which helps reduce habitat for pests and minimizes the risk of fungal infections. The removal of these branches also allows more light to reach the ground, encouraging the growth of grass or understory plantings.
The optimal time for structural pruning is during the dormant season, specifically in late winter or early spring before new growth begins. Pruning during this period minimizes stress because the tree’s metabolic processes are slowed down. This timing allows the tree to begin its natural healing process, known as compartmentalization, as soon as the growing season starts.
Pruning should be avoided in late summer and fall (August to November). Making cuts then can stimulate new, tender growth that lacks time to harden before winter frosts, making the tree vulnerable to cold damage. Pruning during warmer seasons also increases the risk of pest and disease infestations attracted to fresh cuts.
Essential Tools and Safety Preparation
Successful pruning requires sharp, clean tools appropriate for the size of the branches being removed. Hand pruners with a bypass action are effective for small twigs up to about a third of an inch in diameter. Long-handled loppers handle branches up to 1.5 inches, providing increased leverage for a clean cut. Any branches exceeding 1.5 inches require a sharp pruning saw for smooth, precise removal.
Before starting, all cutting blades should be sanitized, often with rubbing alcohol, to prevent the transmission of pathogens between trees. Safety is a major consideration, so wearing sturdy gloves and eye protection is necessary to guard against sharp debris.
When removing branches high off the ground, work from a stable, level surface whenever possible. Avoid using ladders or working above shoulder height when cutting large limbs, as this increases the risk of an accident. Focus only on branches that can be safely reached from the ground or a secure, low platform.
Step-by-Step Limbing Technique
The first step in limbing up is determining the final height, remembering that cedar trees do not regenerate growth on old wood, making the cuts permanent. Remove only a few lower branches at a time to maintain the tree’s overall health and structure. The goal is to remove the branches back to the main trunk without damaging the branch collar, the slightly swollen ring of tissue at the branch base.
For any branch larger than one inch in diameter, use the three-cut method to prevent the falling branch’s weight from stripping bark down the trunk.
- The first cut is an undercut, made from the bottom of the branch 6 to 12 inches away from the trunk, cutting about one-third of the way through.
- The second cut is a top cut, made a few inches further out from the undercut, allowing the branch weight to break away cleanly.
- The final cut is made on the remaining stub, just outside the branch collar and the branch bark ridge.
Cutting into the branch collar damages the tree’s natural defense tissues, hindering its ability to seal the wound through compartmentalization. The final cut must be made cleanly and should not leave a long stub, but it must not be flush with the trunk.
Post-Pruning Care and Avoiding Common Mistakes
After removing the branches, clear all cut debris from around the base of the cedar to reduce hiding spots for pests and allow for visual inspection. Avoid using wound sealants or tree paint on cedar cuts. These products can trap moisture and pathogens against the tree’s surface, slowing down the natural healing process.
A common mistake is removing too many lower branches too quickly, which severely stresses the tree and inhibits photosynthesis. As a guideline, remove no more than 20 to 25% of the total live foliage in a single year. Another frequent error is cutting too close to the trunk, which removes the branch collar tissue needed for proper wound closure.
Making cuts that are too far from the trunk, leaving a long stub, is incorrect because the tree cannot effectively seal off the excess wood, inviting decay. Proper pruning techniques ensure the tree’s long-term health by allowing it to naturally compartmentalize the wound.