The Art and Science of Pruning

by Donna Porter

Pruning a plant has been defined as a cross between an art and a science. Understanding the physiological aspects of the plant makes it the science while having an eye for balance and a sense of design and beauty makes it the art.

Ok, so I can already hear you locals laughing at this. Pruning here is simply a cross between the machete or chainsaw and the plant. Both shrubs and trees benefit greatly from pruning – proper pruning that is – but for ease of explanation this article will focus on trees. If you have a tree(s) that you desire to keep in your landscape then some basic knowledge on this subject may be helpful to you. If possible, conveying this knowledge to your gardener would be the most advantageous, since they are in charge of the machete. Knowing a few simple facts, and applying them, will result in healthier, longer lasting trees in your landscape or garden and less damage to your property by falling tree limbs.

Properly pruning a tree, especially when young, is a smart thing to do. Obviously, these are its “formative” years, and what happens in this stage of its development will determine its mature shape. Wise placement of plants and trees when planting is even smarter and reduces maintenance needs, including pruning. In other words, think futuristically, before you plant.

There are many reasons why to prune, but controlling or decreasing the size of the plant is probably the most common. Proper pruning also reduces the risk of insect and disease problems (rots), eliminates dead wood (AND ants), shapes and balances the plant, makes for easier grounds maintenance, increases flower and fruit production (if so desired), and prevents hazards. Correct pruning not only can prolong the life of the tree, but it is equal to giving it a “shot” of fertilizer. Removal of a portion of the above ground vegetative growth, while maintaining the same amount of roots, reduces the top growth : root ratio and this is desirable. There is then a greater amount of nutrients and water being delivered to less amount of top growth plus there are more roots anchoring a lighter (in weight) above ground portion. Incorrect pruning can be more detrimental to the health and the longevity of the tree and to the safety of what lies below or around it.

Here in Manuel Antonio/Quepos trees grow quickly and within no time at all can obstruct what was once a clear vista. If that is your case, you live here in Costa Rica and the tree is on your property, you are faced with a challenge of how to best deal with that. Being that professional tree pruning services or Arborists are basically non-existent here, you will more than likely have received recommendations by friends of men that they have hired to perform such “acrobatic stunts”. I must admit, I have been truly amazed and awed to witness how this is done here. To watch this strengthens my belief in evolution; that man did indeed descend from apes. A man with a chainsaw/machete, rope and perhaps another helper will arrive (no ladder is necessary) to shimmy up the tree trunk, sometimes barefoot or wearing shorts, and proceed to “top/butcher” the tree. No doubt they will be removing whatever they can, as easily and as quickly as they can, without giving one iota of thought about the health or form of the tree. With the lack of alternatives you have little choice but to use these primitive and daring services.

With a little knowledge on this subject, you can offer a little salvation to the tree with your two cents worth of assistance. First, it is recommended, if possible, to wait until our summer months, when trees tend to drop some of their leaves. This is helpful for a better examination of the tree’s interior structure and branching. Then, step way back to get a full view of the entire form of the tree. If you see sizeable branches that are obviously jetting high above, or outside of, the rest of the upper canopy, suggest the removal of that entire branch (if it does not totally disfigure the tree) all the way to the main trunk or a secondary branch. Cuts made in the middle of a large limb will produce a flush of undesirable growth from undesirable places. With too many of these types of cuts you will create what I refer to as the “lollipopped” look. This not only looks ridiculous, but it creates denser growth and inhibits good air circulation within the canopy, which is the cause of fungal diseases, which causes rotting.

Also, try to insist (at least give it your best shot) on “clean” cuts. One of my gardeners was determined to demonstrate to me how he can, with a very sharp machete, make a one or two-swipe “clean” cut on limbs 2-3 inches in diameter. Although he was successful on a few cuts, I was still not totally convinced – you still cannot get consistently close cuts as you can with a saw. A small pruning saw (the folding-type Japanese saws are the best or at least a slightly arched saw), can get into more tight places and does not require as much room for use as a machete. Machete cuts require room for the “swing”. Rough, chopped, jagged pruning cuts do not heal correctly (if at all) and therefore allow insects and diseases to enter into the inner wood of the tree. My biggest pruning pet peeve is “stubs”. Do not leave “stubs”. When removing a branch, no matter what size, always cut it as close as possible its point of attachment to the tree, without cutting into the bark at its point of attachment.

Nothing makes me quiver and shiver more than to see a lovely specimen of a tree, in an open location, providing shade, greenery and beauty, swaying in the breeze, minding its own business and not encroaching on any structure, utilities or view, being uselessly massacred, especially with a machete. Once upon a time, there were two beautiful and majestic Ficus benjaminas in a very public spot in Quepos, proudly reaching ten meters or so in height. These trees were so horribly mutilated that I was tempted to get a chainsaw, myself, and cut the poor trees down to the ground to save them (the trees) the embarrassment of living the rest of their days as mangled and stunted freaks of nature (lollipop trees) and to die the inevitable death that would result from this horrendous, so called pruning. This happened about a year ago, and one of the “lollipops” has since died.

I know that we cannot control the way that things are done here in our “adopted” culture. But, possibly, by setting good examples and politely and humbly sharing our knowledge to whomever appropriately can utilize it, we can heighten awareness on certain subjects that perhaps, in time, will change. This probably applies to numerous other subjects and issues in our adopted culture, more important than pruning. But perhaps, by sharing knowledge, we can make a difference in the long run.

Donna is a Horticulturist and has been living and working in Manuel Antonio for 6 years. She consults, designs, installs and maintains gardens for private homes and hotels and also develops botanical trails. Donna is the founder and first Director of the Botanical Garden of the Ozarks and is pursuing the development of a botanical garden in, and for, the Quepos area. [email protected]