Repotting guide

When & how to repot Dipladenia (Dipladenia sanderi)

Also called Dipladenia, Brazilian Jasmine, Rock Trumpet.

More about dipladenia

About Dipladenia

Dipladenia sanderi · also called Dipladenia, Brazilian Jasmine · tropical

A compact, woody tropical vine from Rio de Janeiro bearing shiny leaves and vivid pink trumpet flowers with an orange throat. It blooms prolifically in full sun and moderate humidity. More bushy and container-friendly than its relative Mandevilla, dipladenia suits patios, hanging baskets, and conservatories, requiring bright light and well-draining soil to thrive.

Mature size: Height 1–2 m; spread 30–60 cm

Watch for — Root rot: Caused by overwatering or poorly draining soil. Allow the growing medium to dry slightly between waterings and ensure the pot has adequate drainage holes. Remove affected roots and repot into fresh, dry mix.

How to tell dipladenia needs repotting

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

Thick roots out of the drainage holes, or circling the surface and lifting the plant.
The pot dries out unusually fast and dipladenia wilts between waterings it used to shrug off.
The plant is visibly top-heavy and tips over easily.
Stalled growth and small new leaves over a full season — though with a big specimen, top-dressing is often the better first response before a full 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 dipladenia

Every 2–3 years; top-dress in the in-between years. Dipladenia's growth habit — compact woody twining vine or sub-shrub; less vigorous than mandevilla — sets the pace. A compact, woody tropical vine from Rio de Janeiro bearing shiny leaves and vivid pink trumpet flowers with an orange throat. It blooms prolifically in full sun and moderate humidity. More bushy and container-friendly than its relative Mandevilla, dipladenia suits patios, hanging baskets, and conservatories, requiring bright light and well-draining soil to thrive.

What size pot to step dipladenia up to

Move up exactly one pot size. A heavy dipladenia dropped into a vastly bigger pot sits in a reservoir of wet soil its roots cannot reach, which rots them and destabilises the plant. In the years between repots, lift off and replace the top 3–5 cm of soil (top-dressing) instead — it refreshes nutrients without the shock of a full repot.

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 dipladenia

Early spring, just as new growth restarts, is the ideal window for dipladenia. 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 dipladenia

Consider top-dressing first. If dipladenia is not badly root-bound, scrape off and replace the top 3–5 cm of soil instead — far less shock for a big plant that hates moving.
Get help and one size up. For a full repot, choose a pot just one size larger. A heavy plant needs two people and a stable, free-draining pot.
Ease it out on its side. Lay the plant down, slide the pot off, and gently loosen the outer roots. Do not bare-root a mature specimen.
Repot at the same depth. Add fresh free-draining, sandy or perlite-enriched tropical mix beneath and around the rootball, keeping the original soil line. Firm it so the trunk is stable and upright.
Water and leave it put. Water thoroughly, then leave dipladenia in the same spot and light — moving and repotting at once is what makes it drop leaves.

Aftercare

Leave dipladenia in exactly the same spot and light it was in before — moving and repotting at the same time is what makes a big specimen drop leaves. Water it in well, then let the top of the soil dry before watering again so the larger volume of fresh soil does not stay sodden. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for dipladenia

Dipladenia wants free-draining, sandy or perlite-enriched tropical mix. Use a well-draining potting mix with added coarse perlite or horticultural sand. Avoid heavy or moisture-retentive composts. A slightly acidic to neutral pH (6.0–7.0) suits this species well. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting dipladenia — frequently asked questions

How often should you repot dipladenia?

Every 2–3 years; top-dress in the in-between years for dipladenia. Fully repot dipladenia only every 2–3 years; in the in-between years just top-dress the top 3–5 cm of soil. Step up one pot size in spring with free-draining, sandy or perlite-enriched tropical mix. It is heavy and hates being moved, and a vastly oversized pot holds water against the roots and rots them.

What size pot does dipladenia need?

When is the best time of year to repot dipladenia?

Should you top-dress or fully repot dipladenia?

For a big, heavy dipladenia, top-dressing — replacing the top 3–5 cm of soil — is the gentler option most years, with a full repot only every 2–3 years. A mature specimen sulks and drops leaves when fully repotted, so do it as rarely as the roots allow.

Should you fertilise dipladenia after repotting?

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