Repotting guide

When & how to repot Alocasia Lauterbachiana (Purple Sword) (Alocasia lauterbachiana)

Also called Purple Sword, Purple Sword Alocasia, Lauterbach's Alocasia, Silver Edge Alocasia.

More about alocasia lauterbachiana (purple sword)

About Alocasia Lauterbachiana (Purple Sword)

Alocasia lauterbachiana · also called Purple Sword, Purple Sword Alocasia · tropical

Alocasia lauterbachiana, or Purple Sword, is a striking tropical aroid prized for narrow, wavy-edged leaves with purple-burgundy undersides. It wants bright indirect light, evenly moist but never soggy soil, warmth, and high humidity. The ASPCA lists Alocasia as toxic to cats and dogs, so keep it well out of pets' reach.

Mature size: Typically reaches 0.9-1.2 m (3-4 ft) tall indoors over several years, occasionally taller in ideal conditions, with a spread of roughly 0.6-0.9 m (2-3 ft).

Watch for — Root and corm rot: The most common killer, caused by overwatering or poor drainage, especially in low light. Use a chunky mix, water only when the top third dries, and never let it stand in water.

How to tell alocasia lauterbachiana (purple sword) needs repotting

Repotting on a calendar is less reliable than reading the plant. For alocasia lauterbachiana (purple sword), watch for these signs:

Flowering has tailed off year on year and the clump has become congested and overcrowded.
Lots of leaf and few flowers — a classic sign that alocasia lauterbachiana (purple sword) bulbs or tubers need lifting and dividing.
Bulbs visibly bursting the pot or pushing each other to the surface.
It is the natural dormancy window (foliage yellowed and died back) — the only safe time to lift and split.

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 alocasia lauterbachiana (purple sword)

Lift and divide every 3–4 years once clumps congest. Rather than a true repot, alocasia lauterbachiana (purple sword) is lifted and divided once the clump congests and flowering drops off. Rhizomatous, upright tropical perennial. New leaves emerge from a central corm/rhizome on tall, arching petioles, producing a vertical, sculptural clump of narrow, sword-shaped leaves..

What size pot to step alocasia lauterbachiana (purple sword) up to

Pot size matters less than depth and spacing here. When you replant alocasia lauterbachiana (purple sword), set the bulbs or tubers at the correct depth (a rough guide: two to three times their own height of soil over the top) and space them so they are not touching. A wide, shallow pot suits a clump better than a tall narrow one.

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 alocasia lauterbachiana (purple sword)

The only safe window is dormancy: wait until the foliage has yellowed and died back naturally, lift and divide then, and replant before or at the start of the next growing season. Disturbing alocasia lauterbachiana (purple sword) in full growth or flower sets it back badly.

Step-by-step: repotting alocasia lauterbachiana (purple sword)

Wait for dormancy. Let alocasia lauterbachiana (purple sword) foliage yellow and die back completely. Lifting while it is in growth wastes the energy it is storing for next year.
Lift carefully. Loosen the soil well away from the bulbs/tubers with a fork and ease the whole clump out without spearing them.
Separate the offsets. Gently pull the clump apart into individual bulbs or tubers. Keep only firm, healthy, blemish-free ones.
Replant at the right depth. Reset them in fresh loose, well-draining aroid mix at the correct depth and spacing — not touching — so each has room to bulk up.
Water in and rest. Water once to settle them, then keep on the dry side until growth resumes. Do not feed until leaves are actively growing.

Aftercare

After replanting alocasia lauterbachiana (purple sword), keep the soil barely moist — not wet — until shoots appear; bulbs and tubers rot in cold, saturated soil. Once leaves are growing strongly, resume normal watering. Hold off feeding until the plant is in active growth again.

The right soil mix for alocasia lauterbachiana (purple sword)

Alocasia Lauterbachiana (Purple Sword) wants loose, well-draining aroid mix. Use a chunky, well-draining peat- or coco-based mix amended with perlite, bark, and a little sand for aeration. Good drainage is critical to prevent the rhizome and roots from rotting. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting alocasia lauterbachiana (purple sword) — frequently asked questions

How often should you repot alocasia lauterbachiana (purple sword)?

Lift and divide every 3–4 years once clumps congest for alocasia lauterbachiana (purple sword). Alocasia Lauterbachiana (Purple Sword) is lifted and divided, not "repotted". Every 3–4 years, once the foliage has died back and it is dormant, lift the clump, separate the offsets, and replant at the correct depth in loose, well-draining aroid mix. Crowding, not pot size, is what reduces flowering over time.

What size pot does alocasia lauterbachiana (purple sword) need?

When is the best time of year to repot alocasia lauterbachiana (purple sword)?

Do you "repot" alocasia lauterbachiana (purple sword), or lift and divide it?

You lift and divide it. Alocasia Lauterbachiana (Purple Sword) grows from bulbs or tubers, so instead of repotting you wait for dormancy, lift the congested clump, separate the healthy offsets, and replant them at the right depth and spacing. Doing this every 3–4 years restores flowering.

Should you fertilise alocasia lauterbachiana (purple sword) after repotting?

Hold off feeding alocasia lauterbachiana (purple sword) until it is in active growth again. Fresh soil already carries enough nutrients to get it re-established, and feeding disturbed roots too soon does more harm than good.