Christmas Cactus Buds Falling Off – Reasons & What to do Next

It takes great commitment to get the Christmas cactus to bloom. That’s not all if you want to enjoy the beautiful blooms ahead. You must provide proper care to the plant to prevent buds from falling off or wilting.

Christmas cactus buds drop is a common problem due to lack of moisture in the air or soil, too much light or heat, and pests or diseases. Moving or disturbing the plant when blooming may also interfere with bud formation.

Christmas cactus buds falling off – Reasons

There are several reasons why buds may fall off a Christmas cactus. They include the following:

1. Extreme temperature changes

A Christmas cactus requires very cool temperatures when blooming compared to other house plants. Generally, they thrive at 60- 70 degrees F, but the temperature should be reduced to around 55 degrees F to encourage blooming.

However, Christmas cactus buds cannot tolerate temperatures below 50 or above 80 degrees F. If you have been heating your house, it might be a reason the buds are falling off.

2. Low humidity

Christmas cacti love environments with high humidity because they draw moisture from the atmosphere. Dry air in a home typically causes buds to drop and wilting leaves.

During the cold season, indoor humidity is usually very low. Also, excessive use of air conditioning or a dehumidifier will lower humidity. You can think of other ways to increase your plants’ humidity without a humidifier.

3. Water issues

All plants require water to survive. However, the Christmas cactus does not need as much water as other house plants. The plant prefers drawing moisture from the air; if you keep adding water, you will ruin the buds.

Overwatering the plant causes root rot because the air does not reach the roots as required. On the other hand, under-watering will put your plant in a drought mood and drop the buds in survival mode. So, know when to water your Christmas cactus for healthy growth.

4. Fertilizers at the wrong time

Although giving the plant fertilizer provides the required nutrients, timing is also important. Typically, Christmas cactus fertilizer requirements are high during the growth season. Fertilizing during the blooming season will cause the buds to fall off.

However, failure to fertilize will kill the plant due to nutrient deficiency. The plant will use all the available nutrients in the soil, and some will be lost through the draining water.

Fertilize the Christmas cactus during spring and summer to strengthen it before forming buds in fall. Ensure to use magnesium and phosphorous fertilizer. Also, Epsom salts are a good source of magnesium for the cactus.

5. Repotting while buds are forming

You might have wanted to repot your Christmas cactus for a while and finally got a chance, even though they are forming buds. Repotting at this point is a mistake, and you might lose all the buds. 

A Christmas cactus loves to be pot-bound. Therefore when you move it to a bigger pot, it will forget everything else, even flowering, and concentrate on growing roots to fill up the pot. You should not repot a Christmas cactus when it forms buds, but wait until it has finished flowering.

6. Diseases

A Christmas cactus can be affected by several diseases, including basal stem and root rot. Basal stem rot appears by forming brown, water-soaked spots at the bottom of the stem. If not treated early, the disease will spread to other stem parts.

Root rot is hard to spot because the roots are covered by soil. The roots will become soggy and black or reddish. Christmas cactus root rot is caused by bacteria and fungi, which grow when oxygen does not reach the roots because of too much water.

The diseases will cause the Christmas cactus to drop buds, and if not treated, it will cause the plant to die.

7. Pests

Pests such as mealybugs are notorious for attacking Christmas cacti. The pests will suck the plant juice, causing it to be weak with wrinkled leaves. If the plant is developing buds, they will all drop.

Failure to intervene the bugs will damage the plant severely, causing it to die. Apart from sucking the plant juice, the mealybug will make the plant more vulnerable to bacterial and fungal infections.

8. Direct Sunlight

Keeping a Christmas cactus outside on a sunny day is disastrous. Like other house plants, Christmas cacti cannot handle direct sunlight and will go into survival mode. The plant will drop all the buds or flowers, and its leaves will turn red.

How to stop buds from dropping

You can do several things to salvage a Christmas cactus that is dropping buds. They include the following:

1.  Keep the temperature within the required range

Ensure to keep the temperature between 60 – 70 degrees F. While using a heater in your house, ensure the temperature does not increase above 70 degrees F, and they do not fall below 50 degrees F during winter.

Keeping the plant in the kitchen could help with humidity but not temperature. The fluctuating temperature caused by the fire while cooking can cause the buds to fall off.

2.  Increase humidity

If you suspect that the buds of your Christmas cactus are falling because of low humidity, the first thing you need to do is a humidity test. To increase humidity levels, you can use natural methods like letting open the lid of boiling water pots or letting the bathroom door open while bathing.

However, you can use a humidifier if the humidity levels are very low. Misting your plant or placing an open container filled with water near the plant can also help provide humidity.

3.  Provide sufficient water

A Christmas cactus should be watered only once a week. The most effective way to know whether to add more water is by checking the moisture content in the soil. Poke a hole in the soil and use your finger to check.

Water only if one inch of the topsoil is dry. Depending on temperature and humidity, you can spray the leaves with water once or twice a week.

4.  Control pests and diseases

To control pests, use systemic insecticide ideal for house plants. For mealybugs, you can use a soft toothbrush to remove them. You can also use a cotton swab dipped in alcohol, but be careful, as too much alcohol will damage the plant.

Treating diseases using fungicides can be tricky because each pathogen requires a specific fungicide. However, you can remove the affected part to treat the basal stem rot.

For root rot treatment, remove the Christmas cactus from the pot and rinse the roots with water. Trim the rotten roots and put the plant in a new pot with new potting soil.

Conclusion

During winter, a Christmas cactus will form buds that will sprout into lovely flowers. The buds are formed after keeping the plant in the dark for twelve to sixteen hours at night and in bright indirect sunlight for ten to twelve hours for six to eight weeks.

For the buds to grow into flowers, you must continue giving the plant sufficient water and humid and cool temperatures. You should control pests and diseases because they will cause the Christmas cactus to lose buds. Also, avoid repotting or feeding the plant with fertilizer after it has started forming buds.

References:

“Holiday Cacti,” University of Minnesota Extension

“Getting Christmas Cactus to Rebloom,” PURDUE University