Why are my Christmas cactus buds falling off? 5 probable causes

If you’re a fan of festive plants but have noticed your Christmas cactus buds are drooping, it’s imperative that you get the necessary information quickly, to give your blooms the best chance of flourishing throughout the period holidays and beyond.

As one of the best Christmas houseplants, we all want our Christmas cacti to do well. But as the best Christmas cactus care tips will tell you, these plants are delicate, and poor conditions – such as changes in temperature and humidity – can cause their buds to drop.

So if bud drop is one of the Christmas cactus problems you’ve been experiencing lately, you’ve come to the right place. We asked the experts what causes Christmas cactus buds to drop and what can be done about it.

(Image credit: Getty Images)

Why are my Christmas cactus buds falling off?

When we asked the experts why your Christmas cactus buds might drop, they explained that these plants are very sensitive to changes in their environment.

“Most often, Christmas cacti are purchased from garden centers or other places where they have been placed in a greenhouse with controlled temperature, humidity level and lighting,” says gardening expert Graham Smith at LBS Horticulture. “Sometimes just moving a cactus into your home after it has lived in that climate can cause the buds to drop, as this is their response to a change in their environment.”

But if there was a delay between your Christmas cactus arriving in the house and its buds dropping, there could be a number of other factors to blame.

1. Watering Problems

Knowing how often to water a Christmas cactus is essential if you want to prevent buds from dropping. These plants need to be watered every two to three weeks, and an inconsistent watering schedule can lead to shedding.

“Fluctuations in humidity levels can cause stress in plants, which will affect bud formation,” says Graham. “To avoid this, maintain a consistent watering schedule and allow the soil to dry out completely between waterings.”

If you water your Christmas cactus more than once a fortnight, it could cause the buds to drop.

2. Lack of humidity

(Image credit: Getty Images)

Increasing humidity levels is a good method for revitalizing a Christmas cactus, and it turns out that lack of humidity can also be to blame for bud drop.

“As they are tropical plants, Christmas cacti thrive in 50 to 60 percent humidity, which is higher than the humidity in the average home,” says Graham. “They can survive at levels slightly lower than that, but if the air is too dry it can cause the buds to drop.”

Use a mister to mist your Christmas cactus regularly to mimic the humid environment in which it thrives. “Or try placing the plant pot on a shallow tray of pebbles filled with water,” suggests Graham. “But don’t let the roots or soil sit in water.”

Eidoct Glass Plant Mister Spray

3. Temperature

Another common cause of Christmas cactus bud drop is poor weather. For optimal bud production, the plant needs temperatures of around 18°C, which is why getting Christmas cacti to flower in winter can be tricky.

The recent drop in temperature could therefore be a probable cause of the dropping of the buds of your plant. “Avoid keeping your Christmas cactus in drafty areas,” advises Kate Turner, gardening expert at Miracle-Gro. “But also, keep it away from radiators and other direct heat sources like an open fire.”

4. Light Levels

The amount of light a Christmas cactus receives can also have a big influence on the health of its buds.

“As it approaches its flowering period, the cactus will need long periods of darkness to start flowering,” explains Graham. “From September to October, the plant should be placed in a room where it will benefit from at least 13 to 14 hours of darkness per night.”

Ideally, Christmas cacti will naturally benefit from this darkness as the days shorten in winter, but any interruption can affect the plant. As such, moving your Christmas cactus in an attempt to find the best location may cause the buds to drop, as can keeping it in full sun – indirect sunlight is best.

(Image credit: Getty Images)

5. Soil fertility

Finally, if soil fertility is poor, this can also cause buds to drop. ‘If The soil the Christmas cactus is in is not very fertile, which may mean it won’t flower,” says Graham. “Depleted soils can lead to several nutrient deficiencies, such as nitrogen and magnesium, which are essential for plant growth.”

Use peat-free compost and a well-draining pot to house your plant, and it may help to add fertilizer to the soil if it’s really struggling. You may want to repot your Christmas cactus if you think the soil conditions are not good.

Miracle-Gro Compost for cactus/bonsai without peat – 10l

Pink cactus and Christmas pot

Organic Cactus baby food, 175 ml – Concentrated liquid fertilizer

FAQs

How do you know if a Christmas cactus is overwatered?

Gardening expert Kate Turner says overwatered Christmas cacti show a few telltale signs, including:

Bud drop – if the plant’s buds continue to drop even though it is in an optimal position, check the humidity level.
Soft, mushy leaves – caused by the plant beginning to rot from overwatering.
Yellowed or shriveled stems/leaves – this may be a sign of overwatering or underwatering.
Wilting of plants – if the plant does not drain water, the roots suffocate, unable to absorb oxygen and begin to rot.

It is important to have the correct watering schedule to avoid any of these problems. You can save an overwatered plant by immediately reducing the frequency of watering (Christmas cacti only need a drink every 2-3 weeks).

What does a stressed Christmas cactus look like?

“The main signs of a stressed Christmas cactus will be wilted leaves, drooping buds and leaf discoloration,” explains former royal gardener Jack Stooks on behalf of Spin Genie. “This is usually caused by poor temperature or direct sunlight.”

Jack explains that Christmas cacti don’t like extreme temperatures and it’s best to keep them in a room where the temperature is fairly constant.

“If buds are falling off your Christmas cactus, the most common reason is that you moved it from a regulated temperature to a cold zone. Let’s say you bought the plant and put it in a cold car for a while before bringing it inside, this will stress the plant, so the buds will fall off over the next few days.