Repotting guide

When & how to repot Queen of the Night (Selenicereus grandiflorus)

Also called Large-Flowered Cactus, Sweet-Scented Cactus, Night-Blooming Cereus.

More about queen of the night

About Queen of the Night

Selenicereus grandiflorus · also called Large-Flowered Cactus, Sweet-Scented Cactus · flowering

Selenicereus grandiflorus is a sprawling, vining cactus from the Caribbean and Mexico, famous for producing the largest and most intensely fragrant cactus flowers in the world — up to 30 cm wide — which open for a single night only. A dramatic flowering specimen for a bright, warm room. Needs support as it sprawls extensively. Generally pet-safe as a true cactus.

Mature size: Stems can reach 3-5 m in length; requires a trellis, moss pole, or hanging basket

Watch for — Root rot: Despite being more moisture-tolerant than desert species, roots will rot in waterlogged soil. Ensure free drainage at all times.

How to tell queen of the night needs repotting

Repotting on a calendar is less reliable than reading the plant. For queen of the night, 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 queen of the night

Every 2–3 years, into bone-dry mix. Queen of the Night's growth habit — sprawling, vining, epiphytic cactus with aerial roots — sets the pace. Selenicereus grandiflorus is a sprawling, vining cactus from the Caribbean and Mexico, famous for producing the largest and most intensely fragrant cactus flowers in the world — up to 30 cm wide — which open for a single night only. A dramatic flowering specimen for a bright, warm room. Needs support as it sprawls extensively. Generally pet-safe as a true cactus.

What size pot to step queen of the night up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Queen of the Night 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 queen of the night

Spring or summer, while queen of the night 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 queen of the night

Repot dry. Do not water queen of the night 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 well-draining but moisture-retentive cactus/succulent mix 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 queen of the night 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 queen of the night 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 queen of the night

Queen of the Night wants well-draining but moisture-retentive cactus/succulent mix. A blend of 50% cactus compost and 50% perlite, with optional additions of orchid bark for aeration, suits this epiphytic grower. Good drainage is still essential, but a richer substrate than desert cacti require helps support its vigorous growth. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting queen of the night — frequently asked questions

How often should you repot queen of the night?

Every 2–3 years, into bone-dry mix for queen of the night. Repot queen of the night every 2–3 years into a snug pot of well-draining but moisture-retentive cactus/succulent mix, 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 queen of the night need?

When is the best time of year to repot queen of the night?

Should you water queen of the night after repotting?

No — not straight away. Repot queen of the night 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 queen of the night after repotting?

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