Repotting guide

When & how to repot Herald's Trumpet (Beaumontia grandiflora)

Also called Herald's Trumpet, Easter Lily Vine, Nepal Trumpet Flower.

More about herald's trumpet

About Herald's Trumpet

Beaumontia grandiflora · also called Herald's Trumpet, Easter Lily Vine · tropical

Beaumontia grandiflora is a vigorous evergreen climber from the Himalayan foothills bearing enormous, heavily fragrant white trumpet flowers up to 13 cm long in spring and early summer, similar to Easter lilies. In frost-free climates it becomes a large wall climber or pergola cover. In cooler regions it needs a spacious heated conservatory. All parts are toxic via Apocynaceae alkaloids.

Mature size: Up to 5-8 m tall with strong support in warm climates; typically 3-4 m in large conservatory containers

Watch for — Root rot in containers: Waterlogged containers in low light and low temperature in winter rapidly lead to root rot (Phytophthora spp.). Ensure containers have ample drainage holes, do not leave saucers full of water, reduce watering to fortnightly in winter, and keep temperatures above 10°C to maintain root metabolism.

How to tell herald's trumpet needs repotting

Repotting on a calendar is less reliable than reading the plant. For herald's trumpet, 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 herald's trumpet 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 herald's trumpet

Every 12–18 months — sooner if roots show fast. Herald's Trumpet's growth habit — vigorous, twining evergreen climber — sets the pace. Beaumontia grandiflora is a vigorous evergreen climber from the Himalayan foothills bearing enormous, heavily fragrant white trumpet flowers up to 13 cm long in spring and early summer, similar to Easter lilies. In frost-free climates it becomes a large wall climber or pergola cover. In cooler regions it needs a spacious heated conservatory. All parts are toxic via Apocynaceae alkaloids.

What size pot to step herald's trumpet up to

Step up one pot size — about 2–3 cm (an inch) wider. Herald's Trumpet 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 herald's trumpet

Early spring, just as new growth restarts, is the ideal window for herald's trumpet. 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 herald's trumpet

Time it for spring. Repot herald's trumpet 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 herald's trumpet out and gently loosen any roots circling the bottom of the rootball.
Repot at the same depth. Put a layer of fresh deep, fertile, well-draining 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 herald's trumpet 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 herald's trumpet

Herald's Trumpet wants deep, fertile, well-draining loam. Grows best in rich, moisture-retentive yet free-draining loam. In the ground, dig in generous amounts of well-rotted organic matter. For large containers, use a John Innes No. 3 equivalent with 20% added grit or perlite for drainage. Slightly acidic to neutral pH 6.0-7.0. Repot infrequently — the plant blooms better slightly pot-bound. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting herald's trumpet — frequently asked questions

How often should you repot herald's trumpet?

Every 12–18 months — sooner if roots show fast for herald's trumpet. Repot herald's trumpet 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 deep, fertile, well-draining loam. Don't jump several sizes — that soggy excess soil is what rots vigorous roots.

What size pot does herald's trumpet need?

When is the best time of year to repot herald's trumpet?

Can you put herald's trumpet straight into a much bigger pot?

No. Even a fast-growing herald's trumpet 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 herald's trumpet after repotting?

Not immediately. Wait about 4 weeks after repotting herald's trumpet. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.