How to Get Your Thanksgiving Cactus to Rebloom
As Thanksgiving approaches, you may look at your Thanksgiving cactus with no blooms, wondering whether it will flower again. Houseplant expert Madison Moulton explains the tricks to getting your Thanksgiving cactus to rebloom year after year.
The Thanksgiving cactus is one of few flowering houseplants that reliably flower indoors, turning your houseplant collection into living Thanksgiving décor. If you’ve purchased your cactus around Thanksgiving time, it’s probably flowering already. But once this initial flowering period is over, there are a few steps to complete to ensure your Thanksgiving cactus will flower again at the right time the next year.
The first few steps are completed at the start of fall to encourage flowering at Thanksgiving. The others must be monitored throughout the year to keep your plants healthy, happy, and primed for flowering.
Keep Them In The Dark
The native conditions of a Thanksgiving cactus influence how it blooms, and recreating these conditions is crucial in getting your cactus to rebloom.
One essential component of these conditions is lighting, or more specifically, darkness. In their native habitats, the Thanksgiving cactus experiences much shorter days and longer nights at the start of fall. Similar to poinsettia plants, long nights trigger the plant to slow overall growth and start producing flower buds.
Unfortunately, it’s tricky to find completely dark spots when growing indoors. Artificial lights can interfere with this cycle, even if there’s plenty of darkness outside your home. And those in warmer areas may have too much daylight for bud production, even in fall.
These short-day plants will need at least 12 hours of darkness (preferably closer to 14) to produce flower buds. To achieve this total darkness, you can place your plant in a dark room like a basement or a closet each night – as long as you don’t frequently open the doors. This process requires some shuffling, as you must bring it back out in the light for 8-10 hours every day.
If you don’t have a spot, you can also create a dark chamber by covering the plant in dark fabric that blocks the light (curtains work well). To avoid damaging the plant, prop the fabric around the container and off the stems, ensuring it reaches the floor for total darkness at night. This can make it easier to move from dark to light each day.
Maintain this routine for a few weeks until plenty of buds have formed. You can then bring your plant back into its regular lighting to enjoy.
There is another vital environmental change that signals the start of fall to your plant – cooler temperatures. Nighttime temperature dips encourage the plant to produce buds, and keeping these temperatures consistent will help maximize blooming potential.
To get a Thanksgiving cactus to rebloom by the end of November, the surrounding temperature should drop to 50°F for several weeks, starting around September. That means keeping a close eye on your heating and potentially moving the plant to the coolest room in your home.
Consistency is key here. Rapid temperature fluctuations will stress the plant and cause any existing buds to drop off the plant. Watch out for drafts from open windows or vents, as this can impact temperatures around the plant without you even realizing it.
Watering correctly is always crucial, but it becomes even more important to watch around blooming time.
Watering too much when the plant is trying to flower will limit the amount of buds being formed, potentially causing them to drop off the plant altogether. In severe cases, it can lead to root damage that will only be resolved by repotting, if it can be resolved at all.
Cooler temperatures and slower growth around fall mean your cactus will draw less moisture than usual. On top of that, a little bit of drought stress can actually improve flowering. As long as you don’t stop watering altogether, it’s better to underwater than overwater at this time.
Reduce your watering schedule in September while still checking the soil regularly. Wait until it is completely dry before adding more water to the soil. After flowering, you can return to your standard watering routine to boost root and stem growth.
Feed In Spring
The previous three points are vital to consider at the start of fall, but they aren’t the only things that impact flowering. Your care throughout the rest of the year will also determine whether your plant has all the resources it needs to flower.
Flowering uses up plenty of energy and nutrients. In containers where nutrients often leech from the soil, it is up to you to replace them so the plant can flower again the following year. This isn’t necessary in fall (and may actually hinder flowering), but it does improve growth in spring and summer to give it that extra boost.
A balanced fertilizer or succulent and cactus fertilizer works well for Thanksgiving cacti, giving them all the nutrients they need to grow and flower. Liquid fertilizers usually work best, applied around once a month during the warmer seasons.
Ensure you don’t overfertilize by following the instructions on the packaging and keeping track of your fertilizing schedule. Overfeeding, especially around September, will negatively impact your chances of flowering around Thanksgiving time.
Repot Only When Necessary
Spring is an excellent time to repot if your plant needs extra room. Unfortunately, if it doesn’t need the extra room or if you repot incorrectly, you may be jeopardizing your flowering in the fall.
Thanksgiving cacti prefer to be a little root-bound, especially if you want plenty of flowers. If you repot too early when the plant doesn’t need it, it will need time to adjust to its new conditions, focusing on root establishment and survival rather than flowering.
Similarly, repotting into a container much larger than the current one or repotting into the wrong soil mix will create problems around flowering time. Choose a container around one or two sizes up at most, planting into a well-draining succulent and orchid or cactus soil mix for improved root health.
That’s not to say you should never repot at all – it is still an essential component of long-term care. However, only repot when the plants really need it, and make sure you keep conditions (particularly soil) as consistent as possible.
Humidity is the final component in flowering and is the one that people often forget about. Although the cactus classification may make you think of dry and sandy deserts, these cacti actually originate from the jungle, where humidity is high throughout the year.
Maintaining high humidity won’t only improve growth but also greatly improve flowering and limit your chances of bud drop. Keeping humidity around 50% or above is preferred, but they can manage slightly lower humidity levels if all other conditions are met.
If your indoor air is much drier (around 30% or lower), you must raise humidity to get the plants to flower. A pebble tray, grouping plants close together, or choosing a high-humidity room can raise humidity slightly. However, I would opt for a humidifier to help all your tropical houseplants thrive for the best results.
The stems are nice to look at, but if we’re honest, the flowers are the real stars of the show. Follow these steps to ensure you can enjoy Thanksgiving cactus blooms year after year.