Repotting guide

When & how to repot Triangle palm (Dypsis decaryi)

Also called triangle palm, three-sided palm, Neodypsis decaryi.

More about triangle palm

About Triangle palm

Dypsis decaryi · also called triangle palm, three-sided palm · houseplant

Triangle palm is a striking single-trunk feather palm from southern Madagascar, named for the triangular crown formed by fronds set in three vertical ranks. It wants bright light, free-draining soil, and warmth, and tolerates some drought once established. A true palm with no calcium oxalates, it is considered pet-safe by ASPCA standards.

Mature size: Indoors typically 1.8-3 m (6-10 ft) in a container; up to 25-30 ft tall and 12-15 ft wide outdoors, and ~15 m (49 ft) in habitat

Watch for — Yellowing fronds: Often a magnesium or potassium deficiency, which palms are prone to; feed with palm-specific fertiliser.

How to tell triangle palm needs repotting

Repotting on a calendar is less reliable than reading the plant. For triangle palm, 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 triangle palm

Every 2–3 years, into bone-dry mix. Triangle palm's growth habit — solitary single-trunk feather palm; fronds emerge in three vertical ranks (~120° apart), giving the triangular crown — sets the pace. Triangle palm is a striking single-trunk feather palm from southern Madagascar, named for the triangular crown formed by fronds set in three vertical ranks. It wants bright light, free-draining soil, and warmth, and tolerates some drought once established. A true palm with no calcium oxalates, it is considered pet-safe by ASPCA standards.

What size pot to step triangle palm up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Triangle palm 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 triangle palm

Spring or summer, while triangle palm 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 triangle palm

Repot dry. Do not water triangle palm 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 free-draining sandy loam 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 triangle palm 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 triangle palm 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 triangle palm

Triangle palm wants free-draining sandy loam. Widely adaptable but prefers a gritty mix. Combine general potting compost with added perlite and coarse sand for sharp drainage. Use a pot with drainage holes; palms resent soggy roots and dislike disturbance, so repot only when genuinely crowded. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting triangle palm — frequently asked questions

How often should you repot triangle palm?

Every 2–3 years, into bone-dry mix for triangle palm. Repot triangle palm every 2–3 years into a snug pot of free-draining sandy loam, 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 triangle palm need?

When is the best time of year to repot triangle palm?

Should you water triangle palm after repotting?

No — not straight away. Repot triangle palm 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 triangle palm after repotting?

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