Repotting guide

When & how to repot Tree philodendron (Thaumatophyllum bipinnatifidum)

Also called lacy tree philodendron, split-leaf philodendron (large), horsehead philodendron.

About Tree philodendron

Thaumatophyllum bipinnatifidum · also called lacy tree philodendron, split-leaf philodendron (large) · tropical

Tree philodendron (formerly Philodendron selloum) is a large clumping aroid from South America with deeply lobed glossy leaves. It develops a thick trunk over time. Mildly toxic to pets due to insoluble calcium oxalates and best suited to larger rooms.

Thaumatophyllum bipinnatifidum (long sold as Philodendron selloum / bipinnatifidum), native to subtropical rainforests of southern Brazil, Bolivia, Argentina and Paraguay.

A rich but well-draining mix supports the heavy, self-supporting crown and trunk-like stem this species develops.

Mature size: 1.5-2.5 m tall and wide indoors

Watch for — Yellow leaves: Overwatering or root-bound — check before watering more.

Sources: missouribotanicalgarden.org, plants.ces.ncsu.edu, aspca.org

How to tell tree philodendron needs repotting

Repotting on a calendar is less reliable than reading the plant. For tree philodendron, 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 tree philodendron 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 tree philodendron

Every 2–3 years; top-dress in the in-between years. Tree philodendron's growth habit — large clumping aroid with thick trunk — sets the pace. Tree philodendron (formerly Philodendron selloum) is a large clumping aroid from South America with deeply lobed glossy leaves. It develops a thick trunk over time. Mildly toxic to pets due to insoluble calcium oxalates and best suited to larger rooms.

What size pot to step tree philodendron up to

Move up exactly one pot size. A heavy tree philodendron 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 tree philodendron

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

Consider top-dressing first. If tree philodendron 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 rich aroid 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 tree philodendron in the same spot and light — moving and repotting at once is what makes it drop leaves.

Aftercare

Leave tree philodendron 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 tree philodendron

Tree philodendron wants rich aroid mix. Compost with 20% perlite and orchid bark. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting tree philodendron — frequently asked questions

How often should you repot tree philodendron?

Every 2–3 years; top-dress in the in-between years for tree philodendron. Fully repot tree philodendron 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 rich aroid 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 tree philodendron need?

When is the best time of year to repot tree philodendron?

Should you top-dress or fully repot tree philodendron?

For a big, heavy tree philodendron, 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 tree philodendron after repotting?

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