Getting it to bloom

Why won't my Rat Tail Cactus bloom? (and how to make it flower)

Also called Rattail Cactus, Whip Cactus (Disocactus flagelliformis).

More about rat tail cactus

About Rat Tail Cactus

Disocactus flagelliformis · also called Rattail Cactus, Whip Cactus · flowering

Disocactus flagelliformis (formerly Aporocactus flagelliformis) is a trailing epiphytic cactus from Mexico bearing long, slender, bristly stems and vivid cerise-pink tubular flowers in spring. It is a classic hanging basket plant and reliable bloomer given good light and a cool winter rest. True cacti are generally non-toxic to pets.

Plant type: flowering

Watch for — No flowers: The most common cause is insufficient winter rest. Keep cool (5-10°C) and almost dry for 6-8 weeks from mid-autumn to early winter.

The reasons rat tail cactus isn't blooming

Almost every non-blooming rat tail cactus traces back to one of these, roughly in order of how common they are:

It is kept warm and watered all year, so it never gets the cool, dry "stop" signal that flowering depends on.
Not enough light — these are usually high-light bloomers, and a dim spot gives leaves but never flowers.
It is fed too much, especially with nitrogen, pushing soft growth instead of flowers.
The plant is too young or was recently disturbed — many need a few years and an undisturbed root system to bloom.
Watering resumes too early or too heavily after the rest, breaking the cycle.

Treating rat tail cactus the same all year. Without the cool, dry winter rest it grows happily but simply never sets buds.

The fix — how to get rat tail cactus to flower

Give a real cool, dry rest. From late autumn, keep rat tail cactus cool (around 10 °C / 50 °F) and nearly dry for 6-10 weeks — a bright, cool room or porch is ideal.
Maximise light. Give it the brightest position you can the rest of the year; insufficient light is the most common reason it stays leafy and flowerless.
Restart gently in spring. When growth or a bud appears, slowly resume watering and move it somewhere warmer and bright — do not flood it straight away.
Feed lightly and leave it alone. Use a balanced or low-nitrogen feed only in active growth, and avoid rich feeding that pushes leaves over flowers.

Light and feeding do most of the heavy lifting here. Dial in the spot with the light guide for rat tail cactus and get the feeding right with the rat tail cactus fertilising schedule — the wrong feed (too much nitrogen) is one of the most common silent reasons a healthy plant makes leaves instead of flowers.

Bloom season and what to expect

Given a proper winter rest, Rat Tail Cactus flowers in spring or summer once warmth and water return, often briefly but reliably year after year.

Post-bloom care so it flowers again

After flowering, return rat tail cactus to its normal growing routine for the summer, then repeat the cool, dry winter rest each year to keep it blooming.

For everything else this plant needs day to day, see the full rat tail cactus care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.

Rat Tail Cactus blooming — frequently asked questions

Why won't my rat tail cactus flower?

Rat Tail Cactus blooms after a genuine cool, dry winter rest — kept cool (around 10 °C / 50 °F) and almost completely dry from late autumn, then warmth, light and water in spring trigger the flowers. The most common reason it is not happening: It is kept warm and watered all year, so it never gets the cool, dry "stop" signal that flowering depends on.

How do I make rat tail cactus bloom?

From late autumn, keep rat tail cactus cool (around 10 °C / 50 °F) and nearly dry for 6-10 weeks — a bright, cool room or porch is ideal. Give it the brightest position you can the rest of the year; insufficient light is the most common reason it stays leafy and flowerless.

When does rat tail cactus normally bloom?