At the elementary school I attended in Tempe, Arizona, I was taught the Arizona Five Cs. They are: Copper, Bovines, Cotton, Citrus and Climate. For this article, I will focus on the fourth C on this list. Arizona’s climate is perfect for growing citrus trees, but not all Arizonans know how to care for them. The biggest mistakes commonly made involve how and when to prune citrus trees. Many people are concerned about WHEN they should prune their citrus trees, although that is not the most important question. For some, the answer might be: NEVER! Perhaps a more appropriate question is: why should I no prune my citrus trees?
Why NOT prune citrus trees
When a Valley resident asked The Arizona Republic landscaping expert when they should prune their citrus trees, this was part of the answer: “Homeowners like to prune their citrus trees to show them off. Did you know? Citrus trees are actually shrubs and their branches grow naturally? Low to the ground? That’s how Mother Nature protects the fruit and bark … “Those who have driven through the ancient groves that still exist in parts of East Mesa can understand this idea of citrus trees as overgrown shrubs. The misconception that citrus trees should be pruned the same way as any other type of tree means a shorter lifespan for many citrus trees in the Phoenix area. That is why I would like readers to ask why They want to cut them out before they wonder when to prune your citrus trees. Whether the goal is to optimize citrus production or simply to make your citrus trees aesthetically add to your garden, you need to consider your overall health when pruning.
How to prune citrus trees
Even if it is done during the most optimal time of year, any pruning should be minimal. As Dave Owens, aka ‘The Garden Guy’ puts it, “Citrus trees like not to prune them. The more foliage and dead wood there is on the tree, the more sun protection the tree trunk will get.” John Begeman, another Arizona gardening expert, notes that “more leaves equals more and better fruit,” and also recommends pruning “only if necessary and only with proper techniques.” As described in a 1987 article by Lowell F. True, there are some cuts that may be necessary. Although it is best to leave a ‘skirt’ (branches that almost touch the ground), it is fine to trim it back enough to facilitate watering and fertilization. Wandering branches can also be cut, especially if they rub against other branches. As for the outer foliage, the silhouette of the tree, this can be “modeled” for aesthetic purposes, as long as great care is taken not to expose too much bark of the tree to sunlight. There is only one type of pruning regardless of the time of year that can and should be done, especially if citrus trees are maintained for their fruit: the elimination of sucker growth. These suckers are also called ‘water buds’ and will sprout from the trunk or even the roots of the tree. A layman may feel this necessary by intuition or by a desire to make the tree look nice, but in fact there is a good reason behind it. True says: “Make sure to remove all suckers that arise below the bud junction [which is the site of grafting]. They are of the rootstock variety and will not bear edible fruit. When allowed to develop, they will take over the top, causing the named citrus variety to become an unwanted variety again. An important pruning ‘when’ involves branches that have died from frost, do not remove this dead wood until after the spring growth has begun, so you can be sure of the extent of the damage.
When to prune citrus trees in Arizona
The best time of year to prune citrus trees is spring. If you prune them between mid-March and early May, the trees are less likely to be damaged by extreme temperatures. Citrus ripens in late fall, roughly November through February for most varieties. Minimal pruning is also acceptable during this harvest time. During the winter there is danger of frost, and during the summer there is the opposite problem. Citrus trees are very sensitive to sun damage, especially during the hottest months of the year and during the hottest hours of the day. If the tree is not shaded in the afternoon, any bare trunks or branches should be wrapped or painted (whitewashed) to protect from the sun. The tree is most vulnerable where it receives direct sunlight in the afternoon – the southwest exposure. This is why it is so important not to over-prune citrus trees: branches exposed to direct sun burn, and full exposure to the trunk can kill the tree completely.
In conclusion, I would like to re-emphasize that knowing when to prune citrus trees is not as important as understanding how to prune citrus trees. The number one rule for knowing when to prune citrus trees is the sun. The number one rule for how to prune citrus trees is minimalism. Remember, they are really just big bushes.
SOURCES (in order of citation within the article): The Republic of Arizona: Gardens of the Southwest, Diana Balazs. The Garden Guy: “Citrus Trees” by Dave Owens. Arid Southwest Gardening Information: John Begeman [http://www.ag.arizona.edu/gardening/news/articles/3.30.html], University of Arizona College of Agriculture and Life Sciences. “To prune or not to prune, that is, citrus”. Lowell F. True, University of Arizona College of Agriculture “Citrus in the Home and Garden”