Most Christmas cactus problems start with watering that doesn’t match the pot, and the rest with a sudden change in light or temperature. Check the soil and the base of the plant first, because that tells you which problem you have.
The Christmas cactus (Schlumbergera) isn’t a desert cactus. It grows on trees in humid Brazilian forests, which is why it likes more water than a typical cactus and reacts badly to weeks of bone-dry soil. Our Christmas cactus care post covers the basics. This one is for when something is wrong.
Limp or wrinkled leaves
Limp, soft segments come from two opposite causes, so the first step is to tell them apart.
Too dry
- The soil is dry well down into the pot, and the pot feels light.
- Segments look wrinkled and slightly flat, but the stems are firm at the base.
- The plant perks up within a day or two of a thorough drink.
Water until it flows from the drainage holes, let it drain, and from then on water when the top 2 to 3 cm are dry.
Too wet (root rot)
- The soil is still damp or soggy, and the pot may smell sour.
- Stems feel soft or mushy near the base, and segments look limp even though you watered.
- The plant looks worse after each watering.
Unpot the plant and look at the roots. Healthy roots are pale and firm. Rotten ones are brown or black and soft. Trim the bad ones with clean scissors and repot into fresh, fast-draining mix in a pot with holes. Our root rot guide has the steps. If most of the roots are gone, take cuttings (see below).
A pot that’s too big, or soil that has broken down into a dense, peaty lump, can also make a plant go limp. A mix with good drainage is the best prevention. Our guide to Christmas cactus soil explains what to look for. Our Succulent & Cactus Mix, made of pumice, coco coir, perlite and charcoal, is one option. It contains no fertilizer.
Leaves turning red or purple
A red or purple tinge on the edges is common, and it isn’t always serious.
- Strong light, such as a summer window or direct sun through glass. The pigment acts as a sunscreen. Move the plant back or add a sheer curtain.
- Cool temperatures. Cold nights near a window, around 10°C or less, can tint the segments.
- Root stress. If rot or dryness has damaged the roots, the plant can’t take up water properly and the leaves can redden.
- Dry spells. Too little water can bring it on as well.
If the plant is firm and otherwise healthy, the tint is cosmetic. Fix the light or temperature, and new growth comes in green.
Leaves or segments falling off
Christmas cactus segments are attached loosely and pop off easily when touched. A couple of dropped segments after you move the plant is no cause for worry. Many falling at once is a sign of a problem.
Possible causes:
- Overwatering or root rot, as above
- Underwatering for a long time
- Sudden temperature changes, such as a cold draft from a door or a hot vent drying the plant
- Pests. Check for mealybugs, which look like small bits of cotton in the joints. See mealybugs, and follow the label of any treatment you choose.
- Handling. Segments detach if the plant is bumped or turned often.
The segments that drop are still useful, because they can be rooted.
Buds dropping
This one hurts, because it happens just as you’re expecting flowers. Buds fall when something changes after they form:
- Moving the plant to a new spot, or turning the pot
- Drafts, or radiator heat
- Soil that’s too wet or too dry
- Not enough light
- Temperatures much above about 24°C or below about 10°C
Once you see buds, pick a bright spot out of drafts and leave the plant there. Keep watering consistent, and don’t fertilize heavily at that point. For what triggers buds in the first place, read how to get a Christmas cactus to bloom.
Other leaf problems
- Pale, yellowish segments mean too much direct sun, or a long gap without fertilizer. A weak, diluted houseplant fertilizer in spring and summer, following the label, usually helps.
- Brown, corky patches at the base are usually normal woody growth in old stems. If the stem is soft, it’s rot.
- Sticky residue or white fluff points to mealybugs or scale insects.
- Black or brown spots that spread suggest a fungal problem from wet conditions. Cut off the affected segments and let the plant dry.
Rescuing a plant with cuttings
If the roots are lost, you can start again from the healthy top growth.
- Twist off Y-shaped pieces of two to four segments that are firm and green.
- Leave them on a counter for one to two days so the ends callus.
- Push the bottom segment about 1 cm into moist, gritty mix. Several in one pot makes a fuller plant.
- Water sparingly and place the pot in bright indirect light.
- Roots form in a few weeks, and new growth shows it worked.
More detail is in propagating a Christmas cactus.
A simple routine that prevents most problems
- Bright indirect light, away from hot direct sun
- Water when the top few centimetres of soil are dry, and empty the saucer
- A pot with drainage and a fast-draining mix
- A steady spot, with no drafts and no sudden moves once buds form
- Room temperatures between roughly 15 and 22°C
