was taught the Five C’s of Arizona when attending Elementary school in Tempe, AZ. These were: Cattle, Copper, Citrus, Climate, and Cotton. This article focuses on the fourth factor in the list, climate. While the climate in Arizona is great for citrus tree growing, not everyone understands how to properly care for these trees. One of the largest and most common mistakes made, is knowing when and how to prune a citrus tree. While many stress over ‘when’ to prune a citrus tree, this is not the most significant question. There are some citrus trees that may never need trimmed. The real question may be ‘why should citrus trees not be trimmed?”
Why Citrus Trees Should NOT Be Trimmed
A garden expert with The Arizona Republic was asked by a Valley resident at what time her citrus trees should be trimmed, part of the response included “Homeowners often trim for appearance, but do not realize citrus trees are actually a bush with naturally low growing branches. This is the natural method for protecting bark and fruit…”.
People that drive by the old groves in East Mesa may see old citrus trees and consider them to be overgrown shrubs. It is a common misconception that trimming citrus trees is the same as another tree type, and can cause a shorter citrus tree lifespan in Phoenix.
For this reason, I prefer readers to begin asking ‘why’. What is the reason for trimming the citrus tree? This should be asked prior to ‘when’ citrus trees should be pruned. The overall health of the citrus tree should be considered whether the goal is fruit production optimizing, or just making it appealing to the landscape.
How to Trim a Citrus Tree
When trimming/pruning citrus trees, even at the optimal periods, it should be minimal. It was stated by ‘The Garden Guy’, Dave Owens that “Citrus trees prefer to grow naturally without trimming. The more deadwood and foliage, the better protection from the sun.”
Also, John Begeman, also an Arizona garden expert indicated “The more leaves a citrus tree has, the more fruit and better taste.” In addition, he recommended only pruning “If you must, and only with correct technique”.
A 1987 article from Lowell F. True outlined that while some trimming could be required, but the best approach is to leave low hanging branches, referred to as a ‘skirt’. If trimmed, it should only be enough to provide easier fertilizing and watering. Trimming of errant branches can be done, especially when rubbing against other branches. Meanwhile, the tree’s silhouette created by outer foliage can be ‘shaped’ for appearances, but proper techniques and care should be taken to avoid allowing too much bark to be exposed to sunlight.
There is a single pruning technique that should be used, no matter the time of year, even more important if citrus trees are maintained for fruit. This technique is known as removal of sucker growth. Also referred to as ‘water sprouts’, these suckers sprout out the tree trunk and sometimes the roots. While a layman might find it necessary from desire or intuition towards making the citrus tree more appealing, there are good reasons behind this. It was said by True to “Ensure all suckers are eliminated when developing under the bud union (site of grafting). These are rootstock variety which do not bear an edible fruit. If allowed to develop, suckers take control it will cause your edible fruit to revert into an undesired variety.”
A significant ‘when’ associated with pruning includes limbs which were killed by frost. These should not be removed until after the spring growth has begun, this way you’re sure how bad damage is.
When to Trim Citrus Trees in Arizona
Spring is the optimal time for trimming citrus trees. If they are trimmed between the middle of March to early May, it reduces the risk of the tree being damaged by extreme temperatures. The citrus fruit is ripened during late fall, with most varieties coming in between November to February. It is acceptable to do minimal pruning through this period.
During summer there is risk of heat damage, while winter can cause danger from frost. Citrus trees a very sensitive when it comes to sun damage, especially in the hottest months and days in Arizona heat. If your citrus tree is not properly shaded through the afternoon, any bare branches or trunks will need wrapping or painted (aka. Whitewashed) to add protection from the sun. The areas exposed to direct sunlight in the afternoon are the most vulnerable, these will be on the Southwestern sides. This is the reason over pruning your citrus trees should be avoided. Any branches in direct sun will be burnt, while direct sunlight exposure to the trunk can fully kill the tree.
These are the reasons I emphasize the importance of knowing how and why to trim citrus trees, instead of when you should trim citrus trees. The key factor for when to trim, is the sunlight. The key factor for how to trim a citrus tree is keep it minimal. After all, they are all simply large bushes.