Rat tail cactus (Disocactus ‘flagelliformis’) produces round, vine-like stems which can reach a length of 4 to 6 feet. These long, slender stems have shallow ridges and resemble a rat’s tail giving rise to its common name of rat tail cactus.
It is native to Central America and Mexico where it grows either in the soil or in cracks and crevices in trees or between rocks. It produces 2-inch tubular flowers in the late spring.
Flower color ranges from purplish-red to pink or orange. Rat tail cactus is grown as a houseplant but can be summered outside if preferred.
Light and Temperature Requirements
The rat tail cactus thrives in full sun and loves bright, direct sunlight when grown in the house. Grow rat tail cactus in a sunny western or southern window. If your home does not receive enough direct sunlight for the rat tail cactus consider purchasing a quality plant light to provide supplemental light.
The rat tail cactus typically performs well under normal household temperatures, but it will suffer if temperatures rise above 90 degrees. During the winter when the cactus is dormant it prefers temperatures between 45 and 50 degrees. Moving your rat tail cactus to a cool location for the winter will provide it with the rest it needs and will promote flowering in the spring.
Unlike many desert cactus the rat tail cactus prefers soil that is slightly moist during the growing period, typically from early spring through the fall. During the fall and winter months when the plant is dormant it prefers soil that dries out between watering.
Soil & Fertilizing
Rat tail cactus thrives in loose, well-drained soil but does not do well in all-purpose potting soil as it is too heavy and can cause issues with drainage. Use cactus or succulent potting mix for your rat tail cactus. You can purchase cactus and succulent potting mix at your local home improvement center or anywhere that potting soil is sold.
Alternately, you can make your own potting mix for your rat tail cactus by mixing equal parts all-purpose potting soil, perlite and builder’s sand. Builder’s sand is coarser than common sand and gives the mixture the texture your rat tail cactus needs. A good potting mixture provides adequate aeration and promotes good drainage keeping the roots of your rat tail cactus healthy.
Rat tail cactus is not a heavy feeder, but it does benefit from liquid fertilizer sprayed on the stems. Use a fertilizer for cactus or succulent diluted to 1/2 strength every 2 weeks during the growing period. Stop fertilizing the plant in the fall when growth slows and resume again in the spring when new growth appears.
Deadheading and Pruning
Old flowers should be removed when they fade, but other than that the rat tail cactus requires little pruning. You can trim it back if it gets too large, or you can remove specific stems to control the size and shape of your rat tail cactus. The ‘tails’ can grow up to a foot in a year and can reach lengths of 4 to 6 feet.
Rat tail cactus are easy to propagate from a section of the stem. Here’s what you need to do.
- Cut a 6-inch section of the stem. You can cut a 6-inch section from the growing tip, or you can cut off an entire ‘tail’ and then cut it into 6-inch sections. Either one will root.
- Place the cuttings in a cool dry place for 3 to 5 days, so the cut ends will form a callous.
- Fill a tray or pot with moist cactus potting mix.
- Insert the cut end of the cuttings into the soil to a depth of approximately 1/8 to 1.4 inch. Use a stick or dowel to hold the cutting in place if it tends to fall over.
- Place the cactus in a location that receives bright, indirect light.
- Keep the soil lightly moist until new roots form in 2 to 3 weeks.
- Repot the new rat tail cactus to their permanent pot once it has established roots..
Do you need to repot a rat tail cactus?
Yes. These plants grow quickly and can fill a pot in no time. For the best results, repot your rat tail cactus in the spring when new growth first appears.
- Choose a pot that is one size bigger than the current one and fill it about 3/4 full of quality cactus growing media.
- Remove your rat tail cactus from its current pot using care not to damage the long tails.
- Position the roots into the soil in the new pot and back-fill around the roots with fresh potting mix. Your rat tail cactus should be planted at the same depth as it was growing in its original pot.
- Water to moisten the soil and place the new planter in similar light as the original.
- Refrain from fertilizing the newly potted plant for 30 days.
Rat tail cactus are stunning plants that look amazing in hanging baskets in a sunny window, but they can be grown in any pot or container that provides good drainage.