Repotting guide

When & how to repot Lady of the Night (Brunfelsia americana)

Also called Lady of the Night, American Brunfelsia, Raintree.

More about lady of the night

About Lady of the Night

Brunfelsia americana · also called Lady of the Night, American Brunfelsia · tropical

Lady of the Night is a tropical shrub in the nightshade family, grown for its creamy-white to pale yellow tubular flowers that release an intoxicating vanilla-like fragrance exclusively after dusk. It blooms prolifically in warm climates in full sun to part shade. All parts are severely toxic to pets and humans. Hardy outdoors in USDA zones 9–11.

Mature size: 2–3 m tall (6–10 ft), spread 1.5–3.5 m (5–12 ft) in optimal tropical conditions; in containers typically 1–1.5 m (3–5 ft)

Watch for — Powdery mildew: White powdery deposits on upper leaf surfaces, especially in late summer with warm days and cool nights and poor airflow. Improve ventilation, avoid overhead watering, and apply a sulphur-based or potassium bicarbonate fungicide at the first sign. Remove heavily affected leaves to reduce spore load.

How to tell lady of the night needs repotting

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

Roots poking out of the drainage holes or coiling visibly around the inside of the pot.
You are watering far more often than you used to because the rootball dries out within a day or two.
Water runs straight through and out the bottom without soaking in.
Top growth has slowed or new lady of the night leaves are noticeably smaller than older ones despite good light.

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 lady of the night

Every 12–18 months — sooner if roots show fast. Lady of the Night's growth habit — upright, rounded, evergreen shrub; somewhat open habit that benefits from regular pruning — sets the pace. Lady of the Night is a tropical shrub in the nightshade family, grown for its creamy-white to pale yellow tubular flowers that release an intoxicating vanilla-like fragrance exclusively after dusk. It blooms prolifically in warm climates in full sun to part shade. All parts are severely toxic to pets and humans. Hardy outdoors in USDA zones 9–11.

What size pot to step lady of the night up to

Step up one pot size — about 2–3 cm (an inch) wider. Lady of the Night grows fast, so it will fill that space within a season, but jumping several sizes at once still backfires: the unused soil stays soggy and rots even a vigorous root system. One size at a time, every year or so, is the rhythm.

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 lady of the night

Early spring, just as new growth restarts, is the ideal window for lady of the night. The plant is moving into its strongest growth phase and re-roots into fresh soil quickly. Avoid repotting in winter dormancy or, for flowering plants, while it is in bud or bloom — recovery is slowest then and you risk dropping the flowers.

Step-by-step: repotting lady of the night

Time it for spring. Repot lady of the night in early spring as growth restarts so it re-roots quickly into the fresh soil.
Choose one size up. Pick a pot about 2–3 cm wider with drainage holes. One step only — a much bigger pot stays soggy and rots roots.
Ease the plant out. Water lightly the day before, then tip lady of the night out and gently loosen any roots circling the bottom of the rootball.
Repot at the same depth. Put a layer of fresh humus-rich, well-draining, slightly acidic loam in the new pot, set the plant so its soil line is unchanged, and backfill, firming lightly.
Water and pause feeding. Water once to settle the soil. Hold off fertiliser for about a month — fresh mix already has nutrients and feeding now burns new roots.

Aftercare

Water lady of the night once to settle the soil, then let the surface dry before watering again — fresh mix around the roots stays wetter than the old compacted ball, so the commonest post-repot mistake is overwatering. Keep it out of direct sun for a week or two while roots re-establish. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for lady of the night

Lady of the Night wants humus-rich, well-draining, slightly acidic loam. Prefers moist, humus-rich soil with excellent drainage and a slightly acidic pH of 5.5–6.5. Amend sandy or heavy clay soils with compost before planting. In containers, use a peat-free potting mix with added perlite to ensure drainage. Avoid alkaline soils, which induce iron chlorosis. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting lady of the night — frequently asked questions

How often should you repot lady of the night?

Every 12–18 months — sooner if roots show fast for lady of the night. Repot lady of the night roughly every 12–18 months, in early spring as growth restarts. It grows fast and circles its pot quickly, so step up one size (about 2–3 cm wider) into fresh humus-rich, well-draining, slightly acidic loam. Don't jump several sizes — that soggy excess soil is what rots vigorous roots.

What size pot does lady of the night need?

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

Can you put lady of the night straight into a much bigger pot?

No. Even a fast-growing lady of the night should only go up one pot size at a time. A vastly oversized pot holds a reservoir of wet soil the roots cannot reach, which stays cold and soggy and rots the roots — the opposite of what you wanted.

Should you fertilise lady of the night after repotting?

Not immediately. Wait about 4 weeks after repotting lady 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.