Thanksgiving Cactus / Crab Cactus
Schlumbergera truncata
description
Thanksgiving Cactus is an epiphytic cactus with pointed stem segments and colourful autumn flowers.
benefits
- Pet-friendly, non-toxic to animals
- Flowering
- Suitable for containers
How to care for Thanksgiving Cactus
sunlight
In Brazil's coastal forests, Thanksgiving cactus grows in tree branches beneath filtered light. Give it bright, indirect light indoors to keep its segments sturdy and encourage autumn buds.
Bright indirect light
Place it near an east window or a few feet back from a bright south or west window behind a sheer curtain. Strong direct afternoon sun can redden or scorch the segments.
Gentle morning sun tolerated
A little early sun is usually fine, especially in winter, but move it back if the segments turn reddish or feel warm. Low light keeps it alive but often reduces flowering.
watering
Water thoroughly, then let the upper layer of mix dry before watering again. Thanksgiving cactus needs moisture around its roots, but it quickly declines in heavy, constantly wet soil.
Spring and summer
About every 7-10 days is a useful starting point. Water when the top 2-3 cm of mix feels dry and the pot is noticeably lighter, then let excess drain away.
Autumn flowering
Check about weekly. Keep the mix lightly moist rather than soaked while buds and flowers are present, as a bone-dry root ball can contribute to bud drop.
Winter and low light
Water roughly every 2-3 weeks, only after the upper third of the mix has dried. Warm rooms, bright light, small pots, and airy mixes dry faster than cool, dim conditions.
humidity
Preferred humidity
Thanksgiving cactus grows as an epiphyte in Brazil's humid forests, so it appreciates moderately moist air. Most homes are suitable at 40-50%, especially if watering is consistent.
Minimum
Very dry air can make stem segments look wrinkled or limp and may contribute to flower buds dropping. Keep it away from radiators, heating vents, and cold drafts while it is budding.
- Check humidity in winter, when indoor heating often dries the air.
- Use a pebble tray with water only as a small local boost, and keep the pot above the waterline.
temperature
Preferred range
Winter minimum
In its Brazilian forest habitat, this epiphytic cactus grows in mild, sheltered conditions. Keep it comfortably warm in bright indoor rooms, away from radiators and hot, dry air. Cooler nights in autumn can help trigger buds, but protect it from frost.
nutrition
March - August
Feed about once a month while new segments are growing, using a balanced liquid houseplant fertilizer at half the label strength. Apply to already moist compost. Stop feeding from late summer through winter, then resume when fresh growth starts in spring.
Nitrogen
Nitrogen supports healthy green segment growth. A balanced fertilizer provides enough without pushing soft, weak growth.
Potassium
Potassium supports sturdy growth and flowering. Regular light feeding during the growing season is sufficient - extra fertilizer will not force more blooms.
soil
Airy, moisture-holding, fast-draining soil
Its epiphytic roots need air as well as steady moisture. Use a loose houseplant or cactus mix improved with orchid bark and perlite, so excess water drains freely without the roots drying out at once.
pH 5,5 - 6,5
This is mildly acidic, which suits Thanksgiving Cactus well. Most peat- or coco-based indoor plant mixes fall in this range, especially when kept free of lime-heavy amendments.