Home Tree Quality Planting Pruning Cue Cards Select Trees Membership Contact

Sub-standard pruning - stripping out the interior

Why prune | Tree structure | Pruning cuts | Prune at planting | Structural pruning | Sub-standard pruning | Is pruning needed
Raising the crown | Thinning the crown | Reducing the crown | Pruning home page

Unfortunately, many people (not professional arborists) misunderstand thinning and subscribe to the practice of only removing branches from the interior of the crown (left photograph). This is often referred to as lions-tailing, over-lifting, over-thinning, or cleaning out. Little or nothing is removed from the ends of the limbs, and this is a mistake. Maybe it is done because it is easy and generates large piles of brush on the ground (see bottom of left photograph). It sometimes seems like people that perform this are charging the unaware customer by the pound because of the huge amount of brush on the ground.

Lions-tailing unbalances the crown by distributing foliage and future growth uncharacteristically toward branch ends. This can cause limbs to over-elongate. Lions-tailing shifts the center of gravity higher where wind speed is greater and creates substantially weakened branches which may break easily in storms or under their own weight. Limbs on trees pruned in this manner can become sunburned on top, crack, and generate many water sprouts. Trees look odd. Branches are forced to sag and droop closer to the ground due to excess end weight. Look carefully at the right photograph to see several branches that drooped over the two year period. With foliage only at the periphery of the crown, sugars must be translocated great distances (perhaps 30 feet or more) down the phloem to aid the tree in compartmentalizing the pruning wounds and other injury. Trees pruned in this manner are also extremely difficult to restore following storm damage.

Removing interior foliage Two years later

Sub-standard pruning home

Copyright © 2011-2016  Urban Tree Foundation  All rights reserved.
This site funded by a grant from
California Department of Forestry and Fire Protection
Urban and Community Forestry Program

CAL FIRE www.fire.ca.gov
Report problems with this web site to

Home  |  Tree Quality  |  Planting  |  Pruning  ]
Cue Cards  |  Tree Lists  |  Membership  |  Contact  ]