Orchids have a reputation for being high-maintenance and difficult to care for. While some types of orchids certainly live up to this expectation, many others are easy to grow and have surprisingly few needs to be concerned with. Pruning is an area of orchid maintenance that is not entirely clear-cut.
Whether or not to prune your orchid is not a matter of life or death for the plant in most cases. However, how and when it is done can contribute to the overall health of the plant, as well as the plant’s ability to direct water and nutrients in the right direction.
You may have heard that trimming off dead flowers or spent flower stems is helpful after the plant finishes blooming. Let’s explore whether or not this is a good idea and how pruning affects orchid growth and blooming.
The Short Answer
Orchids do not require regular pruning, but there are times when pruning can contribute to a healthier appearance and the overall health of the plant. Pruning off dead flower spikes is a common practice to encourage new, healthy growth.
The Long Answer
Pruning orchids is unnecessary; excessive pruning may hinder nutrient storage and slow growth.
Orchids generally do not require pruning. They do not necessarily produce new growth any faster when they are pruned. In fact, pruning too much from certain orchids can reduce their nutrient storage, which supports the production and support of new growth.
How and when you prune your orchid depends greatly on the plant’s growth habit. Sympodial and monopodial orchids have very different needs in this respect. Identifying the type of orchid and its growth habit is key to knowing what type of pruning will be beneficial or detrimental to your orchid.
How to Identify Your Orchid’s Growth Habit
Identifying your orchid’s growth habit is pretty easy. The two categories below, sympodial and monopodial, can be identified by whether growth is produced horizontally along a rhizome with pseudobulbs or in succession along a vertical rhizome.
Orchids in the sympodial group grow horizontally, forming pseudobulbs along a rhizome.
Sympodial orchids: Cattleya, Dendrobium, Oncidium, Cymbidium, Brassavola, and Laelia are those that grow horizontally, sending up pseudobulbs in succession along a horizontal rhizome. The rhizome is a central stem or root that all orchids have.
The pseudobulbs each produce leaves and a single inflorescence in their lifetime. Once the flower spike is spent, that pseudobulb will not produce another, but it still serves a purpose. The spent pseudobulbs are storehouses for energy that provide nutrients to the whole plant.
Regular watering compensates for the absence of water-storing pseudobulbs.
Monopodial orchids include Phalaenopsis, Vanda, Angreacum, Ascocenda, and Rhynchostylis. These grow continuously upward along a vertical rhizome. Leaves are produced successively along the central rhizome, with no individual pseudobulbs. Flower stems and aerial roots grow between the pairs of leaves.
The lack of pseudobulbs makes monopodial orchids less complicated and more basic regarding when and how they can be pruned.
Trimming Dead Flowers
Prune spent flowers to redirect nutrients for new growth, encouraging future blooming.
Pruning the flowers and flower stems is pretty straightforward. It is a good practice to remove spent flowers and their stems. This helps the plant realize it is time to redirect water and nutrients to new growth. In this way, it prompts the orchid to prepare for blooming again in the future.
This is not to say that if you leave the flower stems intact, the plant will not bloom again. In the wild, these plants drop their own spent flower spikes. In cultivation, we seek to expedite the process and maintain a healthy-looking appearance.
Orchid flower stems will never bloom again. Once spent, they are no longer useful to the plant. You can remove the stem as soon as the flowers fall, or you can wait for it to turn brown.
Trim a brown flower stem all the way down, as close to the base as possible. Make sure to use clean, sharp tools; these plants are highly susceptible to fungal and bacterial disease.
If you choose, instead, to trim off your flower stem as soon as the flowers fall off, you may be helping your plant to conserve energy. Once the stem is gone, the plant knows to redirect energy and water for use in developing new growth.
Trimming the green stem on a Phalaenopsis and some other monopodial orchids can result in the plant sending up a second, smaller inflorescence from the node. A green flower stem should be trimmed off about one inch above the first node on the stem. The node that is closest to the base of the plant is the first node.
If you are dealing with a monopodial orchid with more than one flower spike, trim one stem to just above the node and all other stems as close to the base as possible.
If you have a sympodial orchid, be sure not to remove the entire spent pseudobulb, but only the flower stem. For a sympodial orchid with one or more stems, prune them down to the base, as they will not bloom again or produce an additional stem from the node.
Pruning Orchid Foliage
Remove yellowing or compromised leaves for a healthier, attractive appearance.
Orchid foliage lasts for a long time and rarely needs pruning. In fact, pruning a healthy orchid should rarely involve anything but the oldest pseudobulb or set of leaves. Most orchids shed their oldest foliage once a year.
This shedding of foliage commonly happens just before or after the plant blooms. A lot of energy goes into supporting the flowers, and the oldest leaves and pseudobulbs are the first to be drained of their nutrients.
If the bottom leaves on a monopodial orchid turn yellow, the plant is probably just getting ready to drop them. It is perfectly fine to remove them. Removing any leaves compromised by disease or pest damage is also a good idea.
For sympodial orchids, the oldest pseudobulb will be the first to go, as its nutritional stores are depleted. Your plant will eventually drop these dying portions, but it’s okay to speed up the process to maintain a more attractive appearance.
If you notice dying or diseased leaves on your orchid, any time of year is the right time to remove them. Leaving damaged leaves on your orchid can lead to fungal rot, which can quickly move into the rest of the plant, leaving you with a real mess on your hands.
If there is no damaged foliage and you are simply looking at the natural aging process of the plant, it is best to prune these off when the plant is not in bloom. Any pruning while the plant is flowering can drastically shorten the life of your flowers due to stress.
I find that monopodial orchids tend to drop their own leaves before I feel the need to remove them myself. Often, they will fall off while watering and handling the plant. If this happens, you don’t need to worry about it. Just let the plant do its job.
Sympodial orchids take much longer to drop pseudobulbs, and sometimes they won’t fall off at all. They just dry out and turn brown. The ideal time to remove these is when you repot your orchid or divide it, which also involves repotting. While the plant is removed from its container, you can remove any spent pseudobulbs.
Any time you cut into an orchid, the most important thing to do is use a clean tool. A clean, sharp tool makes a clean, neat cut. Clean cuts heal faster and cause less stress to the plant. A razor or small pair of hand shears are good tools to use when pruning an orchid.
What About the Roots?
Inspect orchid roots for damage and remove affected areas to prevent root rot during repotting.
I’d like to briefly discuss the topic of root pruning because the greatest killer of indoor orchids is fungal root rot. You won’t come in contact with your orchid’s roots outside of repotting or dividing the plant, so this is the ideal time to check out those roots and remove any damaged tissue.
Root rot spreads very quickly, so removing affected roots can truly save the life of your plant. When you repot your orchid, take the time to loosen the potting mix from the roots and thoroughly inspect them.
Healthy orchid roots should be somewhat stiff, although pliable, and green, yellow, or white in color. Some orchids, like Phalaenopsis, have very thick, fleshy roots, while others, like Oncidiums, have thinner, more delicate roots.
Before repotting, water your orchid well. This will help give the roots more flexibility so they are not damaged in the process. Remove all potting material from the roots as gently as possible and inspect them for signs of damage.
Rotting roots will appear much darker than healthy root tissue. They will also have a mushy texture and tend to deteriorate when handled. If you see this type of root tissue or roots that have snapped and are dangling, remove these root portions. Don’t leave any rotten tissue attached. It will not recover and may infect other tissue.
Use a sharp tool like a razorblade to remove root tissue as gently and cleanly as possible. The roots of an orchid are sensitive to handling to be gentle. After cleaning up the roots, lightly spray the cuts with a copper-based fungicide. Avoid using cinnamon or hydrogen peroxide as a disinfectant, as these substances will dehydrate the newly trimmed roots and harm the plant.
While routine pruning is not an important part of orchid care, there are occasions when some pruning is helpful or, at least, not harmful to the plant. Always use clean tools when pruning your orchids to avoid transferring detrimental pathogens and interfering with the plant while it is in bloom.