Christmas Cactus vs. Thanksgiving Cactus: How to Tell Them Apart and Get Blooms

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Run your finger along the edge of one stem segment. If it has pointed, claw-like teeth, you have a Thanksgiving cactus. If the edge is smooth and scalloped, you have a true Christmas cactus. That one check settles the question for most plants because the plant sold in most stores as a “Christmas cactus” is usually the Thanksgiving type.

The two are close relatives, and they want almost the same care. The main difference is timing. Thanksgiving cactus tends to bloom in November, and Christmas cactus follows a few weeks later, in December or even later. Below we cover how to tell them apart, how to get either one to flower, and what to do if the buds fall off.

How to tell a Christmas cactus from a Thanksgiving cactus

Both plants belong to the genus Schlumbergera, and both grow arching stems made of flat, linked segments. N.C. Cooperative Extension names two main differences: the shape of the segment edges and the time of year the plant flowers.

• Segment edges. Thanksgiving cactus (Schlumbergera truncata) has jagged, pointed teeth on each segment. Christmas cactus has rounded, scalloped edges with no points.
• Bloom time. Thanksgiving cactus usually opens in November. Christmas cactus usually opens in December or later.
• Growth habit. Christmas cactus stems tend to droop and cascade, which looks good in a hanging basket. Thanksgiving cactus stems tend to grow more upright before they arch.
• Pollen tips. If you want a second check, look at the anthers inside an open flower. Clemson Extension notes they are yellow on a Thanksgiving cactus and purplish-brown on a Christmas cactus.

There is also an Easter cactus, which has rounded segments with small bristles and star-shaped flowers that open in spring. The flowers on Thanksgiving and Christmas cacti are tube-shaped, so a star-shaped bloom is a clue you have the Easter type.

Why your “Christmas cactus” is probably a Thanksgiving cactus

Growers can control bloom time with light and temperature, so they can have Thanksgiving cacti in flower right when stores want holiday plants. That is why most plants sold under the Christmas name are Thanksgiving cacti or hybrids, according to Iowa State University Extension. Some hybrids look like one parent, some look like the other, and some land in between.

Don’t worry about the label. Both plants get the same care, and a plant that blooms in late November is not doing anything wrong. If you want to add one to a gift list, our easy plant gifts for beginners list has other forgiving options.

How to get a holiday cactus to bloom

These are short-day plants. They set flower buds when the nights get longer and cooler, and they need both conditions.

• Long, unbroken nights. University of Illinois Extension says the plant needs at least 12 hours of continuous darkness for five to six weeks to set buds, and that interrupting the dark for a couple of hours can stop it. A lamp in the living room that stays on in the evening is a common culprit.
• Cool nights. Iowa State recommends a spot around 55 to 65°F at night in late summer and fall, and says temperatures above 70°F can prevent flowering even when the days are short.
• Bright days, no direct blast. A bright window with indirect light works well. A spare bedroom or an entryway that stays dark at night is ideal during bud setting.

The timing depends on which plant you have. Many growers start the cool, dark routine in late September for a November bloom and in early October for a December bloom. If you are reading this in mid-November, your plant has either set buds already or it will bloom later than you hoped. Either is fine.

What to do once buds form

Leave the plant where it is. Iowa State Extension advises against moving it while buds are developing, and says you can bring it to a showier spot once the first flowers open. Turning the pot, changing the room temperature or letting the soil dry out completely can all trigger bud drop.

Keep the soil lightly moist while the plant is in bloom. University of Illinois Extension notes that a plant that gets too dry during flowering may drop its blooms. Place the pot in a sink, water until it runs out the bottom, and let it drain before it goes back on its saucer.

Everyday care after the flowers fade

Holiday cacti are not desert plants. They are tree-dwelling cacti from Brazilian rainforests, so they like a looser mix than a typical cactus and more humidity than you might expect.

• Water. University of Missouri Extension says these plants tolerate too little water better than too much, so water when the top of the mix feels dry. Overwatering is the fastest way to cause root rot. Our guide to watering houseplants in winter covers how to adjust as the heat comes on.
• Soil. Use a well-draining potting mix. University of Minnesota Extension warns that heavy, wet soil is a problem for these plants.
• Feeding. Minnesota Extension suggests a balanced houseplant fertilizer at half strength once a month from June through August. Stop feeding as fall approaches so the plant can shift its energy toward flowers.
• Pruning. After blooming, pinch off a few segments from each branch to keep the plant bushy. Those pinched segments can be rooted as cuttings.
• Repotting. These plants tend to flower best when slightly pot-bound, so wait until spring and only go up one pot size.

Pinched segments and soft, limp stems are also worth a look if your plant seems unhappy. Soggy roots are the usual cause, and our post on why houseplant leaves turn yellow in winter walks through the other common causes.

Why your holiday cactus drops its buds

Bud drop is the most common complaint, and it nearly always traces back to a sudden change. University of Missouri Extension lists swings in temperature or light, and very dry mix, as typical triggers. Stray light during the long-night period can also keep a plant from setting buds well in the first place. A cold draft from a window or a spot next to a heating vent can cause the same problem.

If buds fall, don’t panic. Move nothing, keep watering steady, and the plant will often set a few more. It can also help to keep mealybugs in check, since Missouri Extension lists them and scale as the insects to watch for.

Frequently asked questions

Is a Christmas cactus safe for cats and dogs?

The ASPCA lists Christmas cactus as non-toxic to dogs, cats and horses. A pet that eats a lot of any plant can still get an upset stomach, so keeping it out of reach is sensible. For more options, see our list of pet-safe houseplants.

Can a holiday cactus bloom twice a year?

Sometimes. A plant that gets cool nights and long darkness again can flower out of its usual season, and sporadic bloom timing is common in older plants. Most people see the best show once a year when the plant follows the natural fall cycle.

How long do holiday cacti live?

A long time. University of Missouri Extension horticulturist David Trinklein has said that with good care these plants often outlive the person who bought them, which is why so many families have one passed down from a grandparent.

Does a Christmas cactus need direct sun?

No. Bright, indirect light is the goal. Direct afternoon sun can scorch the segments, and in summer a partly shaded spot outdoors works better than a hot, sunny one.

If you want a quick way to spot trouble before it gets serious, grab our free Houseplant Rescue Cheat Sheet. It covers the drooping, yellowing and dropping symptoms that most often show up on holiday plants. Get the cheat sheet here.

Ginger Durett has more than 10 years of experience as a professional grower, including general growing and medicinal cannabis growing. Blair Sutherland is a co-founder of Happy Healthy Living.