The Thanksgiving cactus is a wonderful addition to any houseplant collection, especially in November, when it welcomes the holiday season with a flush of stunning blooms. Gardeners wait months in anticipation for this captivating display. Unfortunately, it doesn’t always come.
Getting your plant to bloom or rebloom is not difficult if you understand its environment. But a few common mistakes or potential issues can cause your Thanksgiving cactus to stop blooming, ruining your living Thanksgiving décor.
Look out for these eight reasons why your Thanksgiving cactus isn’t blooming and how you can fix it to encourage flowering next year.
Unlike typical cacti, this species requires regular moisture.
The first potential cause is a problem that plagues many plants – overwatering.
Thanksgiving cactus is an epiphytic cactus native to jungle environments. That means it needs far more regular moisture than you may expect from a traditional ‘cactus.’ However, as with any cactus (or any houseplant, for that matter), it’s still possible to give them more than they need.
Excess moisture around the epiphytic roots limits airflow and eventually leads to fungal growth and rot. Not only does this cause stress that negatively impacts flowering, but it can also kill the plant if not controlled early. Epiphytes prefer quick showers and well-draining soil rather than waterlogged conditions.
How To Fix
If you’re worried you’ve overwatered, allow the soil to dry out a little and check the health of the roots by moving some soil to the side or carefully removing the plant from its container. A little less moisture than usual can help induce flowering. However, don’t go to the extreme of completely underwatering, as this can also lead to a lack of blooms or bud drop.
After checking the roots, you may need to replace the soil and repot the plant if you notice signs of fungus or soft and mushy roots. If you discover any fungal issues, remove all the soil and trim the damaged roots back to healthy growth to remove the problematic fungus and stop it from spreading. Repot into fresh soil and keep up with care to ensure flowering the following year.
Incorrect Light Levels
To encourage this plant to bloom annually, mimic its natural habitat with shorter days and longer nights.
Most indoor flowering plants need plenty of bright light, and often some limited direct sun, to produce blooms. As a fall-flowering species (hopefully right around Thanksgiving), this plant is slightly different.
To push your plant to bloom again year after year, you need to replicate the flowering conditions of its native habitat. This means short days and long nights – at least 12 hours of darkness per day can push them to produce buds. This should start around six to eight weeks before Thanksgiving if you want them to flower at the right time.
Depending on the conditions in your area and where this plant is placed, this can require some planning. You may need to move your plant around and ensure it is in complete darkness for large parts of the day, up to 14 hours. Even artificial lights can get in the way of bud formation, leaving you incredibly disappointed around Thanksgiving.
How To Fix
Unfortunately, if you’ve only noticed your cactus is not flowering at Thanksgiving, there isn’t much you can do about dark hours this season. Putting them in the dark now won’t help them flower within a few days. The preparation needs to start around September each year for the best results.
Prune the stems back and set a reminder on your calendar to monitor light levels the following year. You can still enjoy these plants for their interesting cascading stems even if they don’t bloom right now!
Temperature plays a crucial role in ensuring timely bloom, even with proper care and plant health.
Sticking with environmental considerations, another essential condition for bud formation is a slight drop in temperature. In their native habitats, temperatures drop to around 55°F, which signals to the plant that it’s time to produce flowers.
If your home is too warm around September (around 65 to 70°F), this temperature will take away the plant’s cue that it’s time to flower. This could be due to the use of temperature controls indoors, or for those that live in much warmer regions, the usual temperatures around late summer and early fall.
Even if there is nothing wrong with your care routine or plant health, you still won’t see flowers at the right time if you don’t consider temperature.
How To Fix
Much like lighting changes, this issue can’t be resolved at Thanksgiving with a quick fix. Managing the temperature from the start of fall is required to allow buds to form at the right time.
Keep the plants in a cooler room in your home (but not too cold), and avoid keeping any heating sources nearby. You can also move them away from brighter areas and relocate to a north-facing window, which will help with lighting levels simultaneously.
Open windows that allow the cool air in can also help trigger flowering, as long as the plants aren’t right in the path of strong drafts that may lead to stress.
Upgrading pot size is essential for houseplant care, but timing is crucial.
Repotting is an important part of houseplant care, as long as you repot at the right time. If you repot around the time the plant should be producing buds, or if you repot incorrectly, you’ll risk the potential for flowering that season.
The first mistake is repotting too early. Rootbound conditions help with flowering rather than hindering it. If you repot when the plant doesn’t need it, it will focus on expanding its root system rather than producing flowers.
Repotting into a container that is too large is another concern. Although you may assume a larger pot translates to quicker growth and a larger plant, the opposite is true. When repotting every few years, choose a pot one size up or two sizes up maximum.
How To Fix
Only repot when absolutely necessary. Roots growing through drainage holes, stunted growth, or disintegrated soil indicate it’s time to repot. If you don’t spot any signs of concern, wait another year to help with flowering.
Whenever you do need to repot, the best time is late winter or early spring, after the plant has finished flowering. Plants need time to adjust to their new conditions and grow new roots after repotting, so repotting when buds are forming will halt the flowering process.
Standard potting soil or regular houseplant mix can hinder flowering.
Even if you do repot at the right time and in the right container, it’s still possible for your Thanksgiving cactus not to flower if you use the wrong soil.
When you hear cactus, you may think of quick-draining and nutrient-poor sandy or gritty soils. But remember, this species is an epiphyte from the jungle rather than the desert, requiring slightly different growing conditions. The epiphytic roots also have specific needs that replicate the airy conditions they experience growing attached to trees.
Repotting into standard potting soil or even regular houseplant mix won’t provide the preferred conditions, negatively impacting flowering. Garden soil is even more risky, as it brings the potential for issues with soil-borne pests and diseases.
How To Fix
Thanksgiving cacti need airy and well-draining soil for optimal root health. These epiphytes, like orchids, prefer soil textures that drain well and give the roots something to cling to.
I use a mix of potting soil, perlite, and orchid bark, but you can also use succulent and cacti mix with extra bark and coconut coir to drain well while retaining enough moisture.
If you’ve repotted into a different mix hindering flowering, it’s best to repot immediately into the right soil. Dense soil mixes not only impact flowering but can also lead to health problems and root rot if you don’t water carefully.
A humidifier is very effective, as it better replicates the jungle-like conditions these houseplants prefer.
Originating from the jungles of Brazil, Schlumbergera truncata is accustomed to high humidity levels in its native habitats. For strong flowering, you need to replicate those same conditions as best you can, limiting stress.
While low humidity is a less common cause of the lack of flowering in this species, excessively dry air can lead to several growth problems. These plants appreciate humidity above 50% in our homes but can handle slightly lower moisture levels and still flower.
However, if your indoor air is very dry (below 30%), your plant is unlikely to flower. Test the humidity in your home and around the plant in particular to determine whether humidity might cause your problems.
How To Fix
There are a few ways to boost humidity, depending on how much of an increase is needed. Grouping several plants together or placing the plant in a higher humidity room within your home (like a bathroom) can marginally improve conditions.
You can also place the pot on a tray filled with pebbles and water, as long as the water does not touch the pot’s base. As the water evaporates, it will slightly improve humidity around the plant.
The best way to control humidity is to use a humidifier. Used correctly, humidifiers can better emulate the jungle-like conditions that these and many other houseplants are used to, improving your chances of flowering.
Sudden Changes In Environment
Once buds develop, avoid moving your plant.
If your Thanksgiving cactus has developed buds on the end of the stems, you’re halfway to a successful flowering season. But there is still one crucial mistake to avoid at this vital time before flowers open – moving the plant.
Sudden environmental changes are one of the main causes of bud drop in Thanksgiving cacti. Differing lighting conditions, humidity, or frequent drafts all disrupt the delicate balance that leads to flowering. The resulting stress will cause the plant to ditch all its flowers to focus on energy preservation and adaption.
How To Fix
Luckily, this fix is simple. If buds have developed, don’t make any changes. The less you do at this time (besides essential watering), the better. Moving the plant now or changing aspects of care like fertilizing may end your flowering season before it has even begun.
If your plant doesn’t bloom on time, you might have a different holiday cactus species.
If you’ve done everything right and still can’t get your plant to bloom in time for its namesake holiday, you may not be dealing with a Thanksgiving cactus at all.
Schlumbergera truncata is one of a few holiday cacti that look remarkably similar, including Christmas cactus and Easter cactus. They are all named after the times of the year they typically flower (in the northern hemisphere).
Later blooms may signal that your plant is a similar but different species of holiday cactus. A closer look at the stems will also tell you what you have. If you do happen to have one of the other species, you’ll need to head out and purchase a true Thanksgiving cactus if you want it to flower this holiday.
While forcing a houseplant to flower may seem complex and problematic, it doesn’t have to be difficult if you know how to replicate the conditions that induce flowering. Look out for any of these potential issues and make sure you rectify them before the blooming season begins.