Christmas cactus buds falling off is usually a sign that something is wrong with your plant, but it can also be a sign that your plant simply has too many buds to handle.
The most common reason for buds to fall off a Christmas cactus is due to the plant receiving too much sunlight during its flowering months. This may sound strange at first, but Christmas cacti require a period of time without much light to promote bud formation.
If you’re still confused don’t worry, I’ll explain everything there is to know about Christmas Cactus buds in this guide.
Why Do Christmas Cactus Buds Fall Off In The First Place?
The list of reasons for the buds falling off can be split into two categories – improper care and too many buds.
Improper care can cause buds to fall off for obvious reasons. If the plant isn’t receiving the right amount of nutrients and sunlight its growth will be affected and as a result so will the buds.
In other cases, you may be providing all the right care and your Christmas cacti may simply grow too many buds to handle. In this case, it will drop a few of the buds to ensure that the remaining buds can flower and thrive.
How Common Is It For Buds To Fall Off A Christmas Cactus?
Since the buds can fall off both when the plant is struggling and also when it is thriving, it’s pretty common for some buds to fall off during the flowering season.
It’s important to understand why the buds fall off to understand if there are any conditions that you can improve to make your plant happier. I’ve listed the 5 most common reasons for buds falling off below so you can quickly identify what is wrong with your plant (if at all) and what to do about it.
5 Reasons Why Christmas Cactus Buds Fall Off
These are the 5 most common reasons why the buds may be falling from your Christmas cacti based on my experience of owning one of these plants for over 4 years.
1. Too Much Sunlight During Flowering Months
As I briefly mentioned before, Christmas cacti require periods with less sunlight to force bud growth. This is because in their natural habitat – jungle environments in Brazil, to be specific – they are conditioned to periods with less sunlight during these months.
You should aim to provide at least 14 hours of darkness a day between September and November, and an interruption to this can quickly cause the buds to stagnate in growth and fall off. Once the buds start to open you can go back to normal sunlight hours, making sure that there isn’t too much direct sunlight each day as this can scorch the leaves and cause the plant to wilt.
(Christmas cactus leaves are actually cladodes, which are leafless photosynthetic units, but for the purpose of this article, I’ll refer to them as leaves as they have a similar function and appearance.)
Overwatering is one of the most common issues for Christmas cacti, and it can cause buds to fall off as it directly affects the number of nutrients that are absorbed by the roots. Christmas cacti are epiphytes, which means the roots are designed to absorb nutrients and moisture both from damp organic material and the air.
If the soil is overwatered and saturated with water the roots will struggle to process water and nutrients, which will cause buds to fall off as they won’t develop properly.
Underwatering causes a similar problem for the buds but due to a lack of moisture in the soil – the roots can’t absorb something that isn’t there.
When I water my Christmas cacti I always check the top couple inches of soil first – if it’s dry then I’ll water the plant, if not I’ll leave it for a few days.
3. Change In Environment
Drastic changes in the environment can shock Christmas cacti and cause them to drop their buds.
This includes drastic changes in quite a few different conditions:
- Temperature – Keep the temperature between 60°F and 80°F (roughly 15°C to 27°C) for optimal growth.
- Sunlight Levels – Sunlight levels are crucial for bud development, especially so during the flowering season. Too much sunlight and you risk sun scorching the leaves and lowering bud development, but if you go too far the other way overall growth will be stunted.
I’ve always kept my Christmas cacti in the same place as they can be very sensitive to changes in the environment.
4. Too Many Buds
Yep, sometimes your Christmas cactus can be so healthy that it produces too many buds to hold onto, and as a result, it will drop some of the buds to ensure that the rest can flower properly.
This will happen if you meet all of the care requirements including the minimum 12 hours of nighttime during the flowering season and can be encouraged by the use of fertilizer as well.
Fertilizers high in phosphorus, such as complete fertilizers, will aid the development of buds. Phosphorus is responsible directly for the growth of flowers, as well as roots and fruits, which is why fertilizers high in phosphorus will help your Christmas cactus to produce more buds (and too many in some cases).
5. Low Humidity
It’s important to get the humidity right for Christmas cacti as they are adapted to the high-humidity conditions in jungles in Brazil.
If the humidity is too low (outside the 50%-60% range) then the overall health of the plant will suffer and it’s likely that some buds will start to fall off. To increase the humidity consider placing your plant next to other houseplants that love humidity such as the spider plant or anthurium to create a mini-climate with higher humidity.
You can also use a humidifier or pebble tray. I avoid misting as it can lead to some problems with repeated use.
How Do I Stop My Christmas Cactus From Dropping Buds?
There isn’t an exact science for completely stopping your Christmas cactus from dropping buds.
You can optimise the conditions so that it won’t drop buds due to improper care, but even under these conditions, it’s likely that a few buds will drop off as your plant starts to grow a lot of them.
The only other thing you could try is to stop adding fertilizer, especially if you use a fertilizer high in phosphorus, as this is responsible for flower growth.