Repotting guide

When & how to repot Mandevilla 'Alice du Pont' (Mandevilla x amabilis 'Alice du Pont')

Also called Pink Mandevilla, Rocktrumpet.

More about mandevilla 'alice du pont'

About Mandevilla 'Alice du Pont'

Mandevilla x amabilis 'Alice du Pont' · also called Pink Mandevilla, Rocktrumpet · flowering

'Alice du Pont' is a vigorous tropical twining vine grown for its large, glossy leaves and trumpet-shaped rose-pink flowers borne all summer. A tender perennial in cool climates, it is treated as a patio container plant or annual and overwintered frost-free. It loves heat, sun and humidity, climbing 3-6 metres on a trellis in a single season.

Mature size: 3-6 m (10-20 ft) on supports in a season; kept smaller, around 1.5-3 m, in containers

Watch for — Poor flowering: Too little light or over-feeding with nitrogen produces foliage but few blooms. Give full sun, feed with a high-potash fertiliser, and ensure warm conditions for the flush to continue.

How to tell mandevilla 'alice du pont' needs repotting

Repotting on a calendar is less reliable than reading the plant. For mandevilla 'alice du pont', watch for these signs:

Roots spiralling thickly out of the drainage holes or pushing the whole plant up out of the pot.
The pot is so packed that water runs straight through in seconds and barely wets the soil.
It has split a plastic pot, or the rootball is a solid mass with almost no soil left when you slide it out.
Growth and (for mandevilla 'alice du pont') flowering have clearly stalled despite good light and feeding — but remember this plant likes being snug, so a little crowding alone is not a reason to repot.

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 mandevilla 'alice du pont'

Only every 2–4 years, when genuinely crowded. Mandevilla 'Alice du Pont' is one of the plants that genuinely prefers a snug pot — it grows and flowers better with its roots a little restricted, so resist the urge to repot it on schedule. Vigorous twining tropical climber that needs a trellis, obelisk or wires to scramble up; not self-clinging. Large oval glossy leaves and showy 7-10 cm rose-pink trumpet flowers all summer. Stems exude milky latex when cut. Prune in late winter/early spring to shape and encourage branching..

What size pot to step mandevilla 'alice du pont' up to

Go up only one pot size — roughly 2–3 cm (about an inch) wider in diameter, no more. Mandevilla 'Alice du Pont' positively prefers a snug pot: it flowers and grows better when the roots are a little restricted. The single biggest repotting mistake here is over-potting — dropping mandevilla 'alice du pont' into a pot two or three sizes up. All that surplus soil holds water the small root system cannot use, stays cold and wet, and rots the roots within weeks. When in doubt, choose the smaller pot.

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 mandevilla 'alice du pont'

Early spring, just as new growth restarts, is the ideal window for mandevilla 'alice du pont'. 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 mandevilla 'alice du pont'

Confirm it actually needs it. Slide mandevilla 'alice du pont' out and check the roots. Only continue if it is genuinely packed — this plant prefers a snug pot, so if there is still soil and room, put it straight back.
Pick a pot only one size up. Choose a pot just 2–3 cm wider with good drainage. Resist anything bigger; over-potting is the main killer here.
Ease it out gently. Water lightly the day before, then tip mandevilla 'alice du pont' out, supporting the base. Tease the outer roots free only enough to stop them circling.
Repot at the same depth. Add a layer of fresh rich, well-drained potting mix, set the plant so the soil line sits exactly where it did before, and backfill around the sides, firming lightly.
Settle it in. Water once to settle the soil, then let it sit. Hold off on more water until the top of the soil dries — fresh soil around a small root system stays wet for a while.

Aftercare

Because the new soil holds more water than the old crammed rootball did, ease right back on watering — let the top of the soil dry before you water mandevilla 'alice du pont' again, or you will rot the roots in the very pot you just moved it to. Keep it out of harsh direct sun for a fortnight. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for mandevilla 'alice du pont'

Mandevilla 'Alice du Pont' wants rich, well-drained potting mix. Use a fertile, free-draining mix with added perlite or grit; slightly acidic to neutral pH. Good drainage is essential to prevent root rot. Incorporate organic matter to sustain the heavy summer-long flowering and vigorous climbing 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 mandevilla 'alice du pont' — frequently asked questions

How often should you repot mandevilla 'alice du pont'?

Only every 2–4 years, when genuinely crowded for mandevilla 'alice du pont'. Only repot mandevilla 'alice du pont' every 2–4 years, and only when it is genuinely root-bound — it flowers and grows best slightly crowded. Step up just one pot size in spring using rich, well-drained potting mix. The key mistake is over-potting: a too-big pot stays wet and rots the roots.

What size pot does mandevilla 'alice du pont' need?

When is the best time of year to repot mandevilla 'alice du pont'?

Does mandevilla 'alice du pont' like to be root-bound?

Yes — mandevilla 'alice du pont' genuinely flowers and grows best when slightly pot-bound, so do not rush to repot it. The mistake to avoid is over-potting into a much larger pot: the excess soil stays wet, the roots cannot use it, and the plant rots. Only repot every few years and only one snug size up.

Should you fertilise mandevilla 'alice du pont' after repotting?

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