7 Signs It’s Time to Prune Your Christmas Cactus
Schlumbergera russelliana, more commonly known as the Christmas cactus, is an epiphytic cactus that’s become a much-loved houseplant, blooming just in time for the holiday season. They make cheerful gifts, and because they’re so simple to care for, many families have an heirloom plant that they have appreciated for decades.
Beyond their festive colors, their unusual growth habit stands out, as they don’t actually have leaves. Instead, they have green, leafless stems that form in segments. The scalloped edges of these segments is an easy identifier when comparing S. russelliana to the Thanksgiving cactus (Schlumbergera truncata), which has segments with toothed, crab-claw-like edges.
If you already have a thriving Thanksgiving cactus, note that their care is nearly identical. Reasons and methods for pruning both cacti are pretty much the same, too. It’s really only the edges of their stem segments that differ.
As low-maintenance as they are, there are quite a few reasons why you may want to prune your Christmas cactus as it gets larger. If you’re worried about harming a family plant or a precious gift, fret not. We’ve assembled a list of signs that it’s time to prune and some basic tips on how the process works.
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End Of Blooming
These epiphytes tend to offer their signature blooms as early as late October and well into January, depending on your region and growing conditions. If you enjoyed the spectacular blooms all season long and hope for even more next year, this is a great time to consider pruning.
Unless necessary, houseplant collectors prefer not to prune these plants before or during the blooming season. Doing so can inhibit the total amount of flowers. In late summer and early fall, these cacti are starting to put all their energy into red, white, and pink flowers.
If you cut pieces off during this time, it interrupts that process. You could end up with seriously lackluster flowers around the holidays. And of course, if possible, you’d rather not prune away the segments that have active flowers attached.
However, once those flowers are spent, they’re not coming back for quite some time. This is a safe time to remove portions of the plant without minimizing any upcoming flowers.
In fact, pruning at this time will encourage the Christmas cactus to start putting energy towards vegetative growth in the form of more segments. You may have noticed that the flowers emerge from the stems. Encouraging the cactus to produce more stems over winter, spring, and fall will give it more real estate to send out more flowers next fall and winter.
Whether you have good reason to prune and have been waiting for the right time, or perhaps you just want to incite the most bountiful growth possible to maximize next year’s display, doing so once your Christmas cactus has finished blooming is the best time.
Leggy Growth
Anyone with a holiday cactus knows that these plants have a unique shape. Each segment seems to grow one or two more segments, and before you know it, the string of segments can become quite long. Overtime, this can sometimes lead to leggy growth, especially in the absence of great lighting.
While these cacti don’t need tons of light—bright, indirect light; dappled sunlight; and partial sun in the morning or evening will all work—they aren’t low light plants. Christmas cacti just won’t thrive in dark corners or low light offices, though we often try to force them to.
You can often keep a Schlumbergera alive in low light conditions for a pretty long time. However, instead of producing multiple segments off each stem, they’ll be more likely to grow long strings of just one segment over and over again, also referred to as “leggy growth.”
If your Christmas cactus has become leggy, there are two major steps towards resolving the problem. One, try to move the plant into a location with more light. Even if you remove the leggy growth now, it will just return if you keep the cactus in the same conditions.
Two, you can prune down the leggy parts. This will inspire the plant to produce more growth lower to the base, resulting in a bushier appearance—as long as it gets enough light. If you simply can’t move it to a brighter spot, consider adding a small grow light. You’ll end up with more blooms, too.
Toppling Over
Whether a Christmas cactus’s growth is leggy, bushy, or anywhere in between, sometimes these plants can become very lopsided, depending on where they’re placed and the angle of their light source.
Your plant may look lovely tucked into a bookshelf, with its tendrils sprawling out. There’s nothing wrong with keeping it there, as long as it’s healthy. With time, you may notice that the portion of the plant hanging off the shelf gets bigger and heavier, causing the pot to fall right over.
If this is the case, there are two ways to resolve the issue. One is to prune, removing its excessive growth until it no longer outweighs its pot. Determine which stems are longest, and remove them close to the base. This should result in improved balance for your plant.
Another way to approach the issue is to repot the plant into a heavier pot. While a plastic nursery pot is easily outweighed, a heavy ceramic pot will not be so quick to fall over.
What’s important to note here is that you shouldn’t repot your plant into a bigger pot, unless it’s outgrown the previous container. If you’re merely repotting to pursue a heavier vessel, choose one of the same size.
A quick houseplant hack is to take the plant—in its current pot—and pop the whole thing into a much larger or heavier pot. No pruning or repotting required. Just be careful not to let the plant sit in water for long after watering if the exterior pot doesn’t have a drainage hole.
Weird Shape
It’s not exactly a pressing issue, as it has nothing to do with the health of the plant or its ability to flower, but sometimes, these epiphytes just develop a weird shape. If you’re displeased with the form your cactus has taken over time, there’s absolutely nothing wrong with pruning to meet your aesthetic desire.
Perhaps the growth has become largely one-sided due to an angled light source, but you want your plant to be round and bushy. Conversely, maybe your cactus has perfectly even growth on all sides, but you want it pressed against a wall, with all growth facing out.
Think of it like trimming hedges to form a certain shape. You can do this with houseplants, too. A good rule of thumb is to never trim more than ⅓ of a healthy plant’s total mass at a time, which can stunt growth or hurt the plant.
Beyond this rule, and as long as you’re using clean, sharp pruners to avoid the spread of pathogens, feel free to just go for it. Snip away.
Since this reason for pruning isn’t time-sensitive, you may want to time it carefully. Fall is not the time to decide you want to reshape your Christmas cactus, because doing so in autumn will inhibit blooming.
Winter is a safe time, but note that the cactus won’t bounce back too quickly, as the days are short. The best time to prune if you want to see quick re-growth is in spring and summer, when the plant is in its most vigorous growing period.
Fungal Disease
Most fungal diseases are most often spread in areas of high humidity and with minimal air circulation. Unfortunately, Schlumbergera aren’t immune to these diseases, and they can spread indoors. These houseplants also prefer slightly above average humidity, 50 to 60 percent, making matters more difficult.
Botrytis blight is a fungal disease often seen on Christmas cacti. Its common name is gray mold, and that’s what it will look like: moldy, gray growth. It’s more often seen on the flowers than the stems, but it will spread to foliage if left unchecked or in extremely high humidity.
This disease spreads via spores and thrives on dead or dying plant matter. Be extra careful when watering infected plants so that you don’t splash the spores around. Removing or pruning away the infected foliage can stop the disease from taking over.
One of the best ways to prevent the spread of fungal disease in general is to improve air circulation. While you can certainly decrease humidity, you don’t want to decrease it outside of the plant’s preferred range. Instead, increase air circulation by pruning away excess foliage.
Use your clean pruners or scissors to remove segments from layers of foliage that overlap or trap each other. Depending on the fungus, you may be able to tell where the air circulation is weakest (where the fungus is most prominent).
Additionally, you may want to consider applying a fungicide to the plant, following the manufacturer’s instructions.
Signs of Rotting
Though Schlumbergera species make low-maintenance houseplants, some of us still struggle with watering too much or too often, which can lead to multiple types of root rot. Basal stem rot can also be a problem, when fungi enters the stem via wounds.
If your Christmas cactus is rotting, pruning will not save it. However, in pruning the houseplant, you will then have new cuttings to start genetic clones as new plants. Whether you’re determined to do your best to save the plant or just want to give up and start over, you’ll be happy that you have healthy backup cuttings.
Root rot tends to start with the roots and make its way up. Depending on how far the disease has progressed, you may discover that the central stem of your cactus is rotting. The stem segments closest to the base may be rotting as well.
When taking backup cuttings of a rotting plant, make sure the cuttings themselves aren’t beginning to rot. Select cuttings that are as far from the base as possible, but refrain from taking the newest growth as single segments. These newer stem segments won’t be very strong.
Once you have your cuttings, leave them on a windowsill or table top for at least a few days, if not a week. If they are infected with rot, you’ll see them decay. If they’re healthy, they’ll be just fine out of soil or water for a little bit.
Sometimes it may seem like cuttings are not infected with rot, even when they are. The test of leaving the cuttings alone for a little bit to see if they decay or not will stop you from wasting time with plant matter that was secretly already rotting.
Taking Cuttings
Finally, you may want to prune simply because you want to take cuttings. These easy-going plants are rewarding and fun, so if you’ve got the right conditions in your home, you really can’t have too many.
You may want to propagate multiple Christmas cacti for your own collection, share with friends, or even stock up on more of this plant for the sake of trading with other hobbyists.
Perhaps your cactus is a family heirloom or holds some type of sentimental value. If so, propagating it is a good idea, just in case something goes wrong with the original host plant.
There are a couple of ways to propagate these epiphytes from cuttings. First off, you can put the cuttings directly in soil and hope that they root. While waiting, make sure that the soil stays moist but not wet. This method involves the least amount of steps, but the cuttings may be more likely to rot before producing roots.
The second method is to put your cuttings in water first, allowing them to establish water roots. Wait until these roots are a couple of inches long, and then plant the cuttings in soil. This method involves more steps but has a slightly higher success rate.
If you are able to obtain a lot of cuttings from your plant, you can try both methods. See which works best for you. To take a cutting, identify a section of stem that has three or four segments. Remove it by twisting where two segments connect.
Pruning Basics
Now that you’re familiar with a wide variety of reasons why you may want or need to prune a Christmas cactus, let’s go over some basic pruning principles.
For example, when you’re pruning your Schlumbergera, where exactly do you cut? Ideally, you cut right at the spot where two segments connect. You can also twist the segments at this location, which causes them to simply separate.
Sometimes it is challenging to cut exactly at the intersection, and instead, you accidentally slice into the segment above or below the connection. This is okay. Either the segment will heal with a calloused wound, or the segment will die and fall off. The segment below it will be healthy and unaffected.
The same thing may happen if you twist off the foliage. You may intend to make a clean twist, but sometimes we pull too hard and accidentally tear a segment of stem. It will either heal or fall off, and that’s okay.
Maintaining good hygiene throughout this process is important. Either sanitize your tools, or wash your hands. This is absolutely crucial if you’re dealing with a plant that has a disease or if you know that nearby houseplants in your collection have been suffering from pests.
