Christmas cactus care: how to get it to flower every year

By Sophie Sparkes · October 2026 · 6 min read

A Christmas cactus can live for decades and flower every winter, but plenty of them sit green and flowerless year after year. The secret is that it is not really a desert cactus at all, and that what you do in October decides whether it flowers in December.

Short answer: keep a Christmas cactus in bright, indirect light and water it when the top couple of centimetres of compost feel dry. To get flowers for Christmas, give it about six weeks of long nights and cool temperatures from early October: a spare room or porch at 10-15°C, with no lamps on in the evening. Once buds form, do not move it, because changes in light and temperature make the buds drop.

It is a forest cactus, not a desert one

The Christmas cactus (Schlumbergera) comes from the mountain forests of south-east Brazil, where it grows on tree branches in dappled shade and humid air. That explains almost every care instruction: it wants more water than a desert cactus, less direct sun, and a free-draining compost because its roots are used to clinging to bark, not sitting in wet soil.

Light

Bright, indirect light is ideal: near an east or west window, or a little back from a south-facing one. Strong summer sun through glass can scorch the stems and turn them reddish. In summer it is happy outside in a sheltered, shady spot, but bring it in before night temperatures fall below about 10°C.

Watering

Water thoroughly when the top 2-3cm of compost feels dry, then let the excess drain away. Do not let it sit in water. In practice that is roughly once a week in spring and summer, and less in winter once it has finished flowering. Limp, wrinkled stems can mean either too little water or, confusingly, too much: if the compost is wet and the stems are soft at the base, the roots may be rotting.

How to get it to flower for Christmas

Christmas cacti set flower buds in response to long nights and cool temperatures. In a warm living room with lights on every evening, they often never get the signal. Starting in early October:

1. Give it long nights. It needs around 12-14 hours of uninterrupted darkness every night for about six weeks. A spare bedroom, landing or porch that is not lit in the evening is perfect.
2. Keep it cool, ideally 10-15°C. Cool temperatures alone can trigger buds even without strict darkness.
3. Water a little less than usual, just enough to stop the stems shrivelling.
4. Once you see buds at the tips of the stems, move it to where you want it to flower, then leave it there.

Why are the buds dropping off?

Bud drop is the most common Christmas cactus complaint, and it is almost always caused by change. The plant has set its buds for one set of conditions and reacts badly when they shift. The usual triggers:

• Moving or turning the pot once buds have formed.
• Sudden temperature changes: a hot radiator, a cold draught from a door, or a chilly windowsill at night.
• Watering extremes: letting it dry out completely, or keeping it soggy.

Pick its flowering spot before the buds open and leave it alone until the flowers finish.

Christmas, Thanksgiving or Easter cactus?

Many plants sold as Christmas cacti in UK shops are actually Thanksgiving cacti (Schlumbergera truncata), which naturally flower a little earlier, often in November. You can tell them apart by the stem segments:

• Thanksgiving cactus: pointed, claw-like teeth along the edges of each segment.
• Christmas cactus: rounded, scalloped edges with no sharp points.
• Easter cactus: rounder segments, often with fine bristles, and star-shaped flowers in spring.

Care for all three is essentially the same; only the flowering time differs.

Feeding, repotting and the rest of the year

After flowering, give it a rest for about six weeks with less water. From spring to late summer, feed every few weeks with a balanced houseplant feed while it is growing. Christmas cacti flower best when slightly pot-bound, so repot only every few years, in spring, into a free-draining mix such as cactus compost blended with multi-purpose compost.

Taking cuttings

They are one of the easiest plants to propagate, which is why so many families have one passed down. Twist off a piece with two or three segments, leave it on a windowsill for a day or two so the end dries and seals, then push the bottom segment upright into a small pot of gritty compost. Keep it barely moist and it should root within a few weeks.

Christmas cactus questions

How often should I water a Christmas cactus?

When the top 2-3cm of compost feels dry, which is roughly once a week in spring and summer and less often in winter after flowering. Water thoroughly, let it drain, and never leave it standing in a saucer of water. It needs more water than a desert cactus, but soggy compost will rot the roots.

Why is my Christmas cactus not flowering?

Usually because it never gets long enough nights or cool enough temperatures in autumn. In a warm room with the lights on every evening, it does not get the signal to set buds. Move it somewhere cool (10-15°C) and unlit in the evening from early October for about six weeks.

Is a Christmas cactus poisonous to cats and dogs?

No. The Christmas cactus is generally listed as non-toxic to cats and dogs, which makes it one of the safer flowering houseplants to have at Christmas. Eating a lot of it may still cause a mild stomach upset, as with most plants, so it is best kept out of reach of a pet that chews.

Why are my Christmas cactus leaves turning red or purple?

Reddish or purple stems are a stress response, most often to too much direct sun, cold, or the plant being very pot-bound and short of nutrients. Move it out of strong direct light, keep it away from cold windows at night, and feed it during the growing season.

How do I make my Christmas cactus bushier?

After flowering, twist off the end one or two segments of each stem. Each break point usually branches into two, so the plant fills out over the following year. Pot up the pieces you remove as cuttings.