Repotting guide

When & how to repot Night-Blooming Cereus (Selenicereus grandiflorus)

Also called Night-Blooming Cereus, Queen of the Night, Large-Flowered Cactus.

More about night-blooming cereus

About Night-Blooming Cereus

Selenicereus grandiflorus · also called Night-Blooming Cereus, Queen of the Night · flowering

Selenicereus grandiflorus, Queen of the Night, is a climbing, scrambling epiphytic cactus from Central America and the Caribbean with slender, ribbed, sometimes aerial-rooting stems. It is celebrated for enormous, intensely fragrant white flowers that open for a single night. It prefers bright indirect light, moderate watering, warmth, and support to climb, rewarding patience with a spectacular fleeting bloom.

Mature size: Stems can climb or trail several metres given support; flowers up to 18-30 cm across.

How to tell night-blooming cereus needs repotting

Repotting on a calendar is less reliable than reading the plant. For night-blooming cereus, watch for these signs:

Roots growing out of the drainage holes, or the rootball lifting the plant proud of the rim.
Soil that has shrunk away from the pot sides and no longer holds water.
The pot is unstable because the plant has grown top-heavy.
Old, compacted, broken-down mix that stays wet too long — for a succulent that is a rot risk, so refresh it even if the pot size is fine.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot night-blooming cereus

Every 2–3 years, into bone-dry mix. Night-Blooming Cereus's growth habit — vigorous climbing and scrambling epiphytic cactus with long, slender, ribbed green stems bearing small spines and aerial roots; needs support, and bears huge, fragrant, white night-opening flowers on mature plants. — sets the pace. Selenicereus grandiflorus, Queen of the Night, is a climbing, scrambling epiphytic cactus from Central America and the Caribbean with slender, ribbed, sometimes aerial-rooting stems. It is celebrated for enormous, intensely fragrant white flowers that open for a single night. It prefers bright indirect light, moderate watering, warmth, and support to climb, rewarding patience with a spectacular fleeting bloom.

What size pot to step night-blooming cereus up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Night-Blooming Cereus stores water and rots in a large pot of slow-drying soil. A tight terracotta pot that dries fast is far safer than a generous plastic one. Never up-pot a succulent by several sizes.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot night-blooming cereus

Spring or summer, while night-blooming cereus is in active growth and warm, is best — roots recover fastest then, and the plant is not sitting in cool damp soil. Avoid repotting a succulent in winter dormancy.

Step-by-step: repotting night-blooming cereus

Repot dry. Do not water night-blooming cereus for several days first. Working with dry roots and dry mix dramatically lowers the rot risk for a succulent.
Pick a snug, fast-draining pot. Choose terracotta one size up at most, with a drainage hole. Have gritty free-draining cactus or epiphytic mix with bark and perlite ready.
Tip it out and clean the roots. Slide the plant out, crumble off the old soil, and trim any black, mushy or dead roots with clean snips.
Pot into dry mix. Set night-blooming cereus at its original depth in dry gritty mix, firming gently. Do not bury the stem deeper than it was.
Wait a week before watering. Leave it completely dry and out of harsh sun for about 7 days so any damaged roots callus. Only then water lightly.

Aftercare

Keep night-blooming cereus completely dry and out of fierce sun for about a week so any nicked roots callus before they meet moisture; watering a freshly repotted succulent is the classic way to rot it. Then resume the normal lean, dry rhythm. Do not fertilise for about 3 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for night-blooming cereus

Night-Blooming Cereus wants free-draining cactus or epiphytic mix with bark and perlite. Plant in a well-aerated, fast-draining medium such as cactus compost blended with orchid bark and perlite to mimic its loose, organic-rich epiphytic rooting sites. Good drainage prevents the trailing stems and roots from sitting wet, which causes rot. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting night-blooming cereus — frequently asked questions

How often should you repot night-blooming cereus?

Every 2–3 years, into bone-dry mix for night-blooming cereus. Repot night-blooming cereus every 2–3 years into a snug pot of free-draining cactus or epiphytic mix with bark and perlite, ideally in spring or summer. Let it sit in dry soil and do not water for about a week afterwards so any nicked roots can callus. Over-potting and watering straight away is what rots succulents.

What size pot does night-blooming cereus need?

When is the best time of year to repot night-blooming cereus?

Should you water night-blooming cereus after repotting?

No — not straight away. Repot night-blooming cereus into dry mix and wait about a week before the first watering so any damaged roots callus over. Watering a freshly repotted succulent is the single most common way to rot one.

Should you fertilise night-blooming cereus after repotting?

Not immediately. Wait about 3 weeks after repotting night-blooming cereus. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.