How to Prune Lemon Trees in Southern California

Eureka, Lisbon and Meyer lemons thrive in southern California.

According to the Master Gardeners of San Diego, three types of lemon trees are grown in southern California: Eureka, Lisbon and Meyer. Each type should be regularly pruned. Pruning provides moderate protection from ant infestation and ensures lemon production continues. Generally, pruning improves tree health. The University of Minnesota recommends you begin pruning when lemon trees are very young to prevent deformity. You can still prune a lemon tree if it is mature. You should always begin pruning at the bottom of the lemon tree and work your way up.

Things You'll Need

• Gardening gloves
• Pruning shears
• Stepladder (if your lemon tree's branches are too high to reach)

Instructions

Preparation

1. 

   Well-fitting gardening gloves will protect your hands against thorns and sharp edges.

   Don your gardening gloves. Lisbon lemon trees generally grow more thorns than other varieties, but each type can cause injury to unprotected hands.

2. 

   Branches touching the ground should be pruned immediately.

   Measure each branch's proximity to the ground. If your lemon tree's branches are not touching the ground but will with some growth, you should prune them as soon as possible. Branches that touch the ground can attract Argentine ants, the most common type of ant in southern California, which may infest your lemon tree.

3. 

   Tying ribbon around the branches of your lemon tree will ensure you prune the correct branches.

   Mark branches you intend to prune by tying string or ribbon around the ideal pruning location. Marking branches ensures you do not accidentally trim the wrong branches.

Pruning Small Branches

1. 

   Sharp pruning tools make tree trimming easier.

   Clip the smallest branch of your lemon tree that needs pruning. According to the University of Minnesota, you should cut the branch to 1/4-inch above the bud. If there is no bud, or you wish to trim it further, prune it back to the side branch nearest the end.

2. Prune the remaining small, low-hanging branches by cutting 1/4-inch above the bud or to the nearest side branch.

3. Ensure each small branch within your reach has been pruned.

Pruning Large Branches

1. Cut the underside of your first large branch about 18 inches from the trunk. Cut at least one-third of the way into the branch. Large branches generally require multiple cuts. When cutting large lemon tree branches, it is imperative you do not tear the bark. Cuts must be clean and even.

2. Cut the top of the branch 1 inch (toward the end of the branch) from your original cut. Continue cutting with your pruning shears until the branch breaks free.

3. Cut other large branches in the same manner. It is helpful to periodically stop pruning and look at your lemon tree from a distance to ensure you are achieving the shape you want.

Tips & Warnings

• Watch your tree carefully after pruning.

• Southern California lemon trees are susceptible to infestation and bacterial infection from Asian citrus psyllids. Asian citrus psyllids are tiny insects that feed on the bottoms of leaves and lay eggs in newly sprouted shoots. Asian citrus psyllid infestation is spread through importation and newly sprouted shoots that have been eaten are susceptible to bacterial infection.

• It is against California law to transplant citrus trees from other states.

• Do not cut branches directly above your head. Instead, offset your body so branches fall beside you.

References

• Texas A & M University: Home Fruit Production - Lemons
• Purdue University: Lemon
• Master Gardeners of San Diego : Citrus for the Home Garden
• University of Minnesota: Pruning Trees and Shrubs
• TreeHelp.com: How to Prune a Tree

Resources

• The San Diego Union-Tribune: When to Plant Citrus
• Palomar College: Argentine Ants
• University of California: Asian Citrus Psyllid