Your Alocasia Polly wants a snug pot just slightly larger than its root ball, not a deep or roomy one. Depth matters far less than a tight fit and good drainage. The right Alocasia Polly pot size hugs the roots with only an inch or so of spare soil around them. This plant even likes being slightly rootbound, so you should resist the urge to give it a big new home. A small pot is what keeps your Polly healthy.
I moved the Polly on my shelf by the bright east-facing window into a pot twice its old size, sure it would love the extra room. I noticed the soil out near the edges stayed dark and wet for a full week. The plant just sat there and sulked, and new leaves stopped showing up. So I pulled it back out and dropped it into a snug container. I found it perked up within days. The depth never changed. The fit did. That was all it took.
Here is what goes wrong in a big pot for you. Polly has a small root system that can only drink up so much water. When you surround those roots with a lot of extra soil, that soil holds moisture your plant cannot use. It stays soggy for days on end. Wet, airless soil is exactly what root rot loves, and root rot is the top killer of this plant. A tight pot dries out at a steady pace, and it keeps your roots breathing the whole time.
A mature Polly only reaches about one to two feet (30 to 60 cm) tall, so it never needs a deep or wide container. When you do size up, step up just one pot size at a time. You can go from a 4-inch pot to a 5- or 6-inch one, but never jump to a 10-inch tub. And always pick a pot with drainage holes in the bottom. Without those holes, water pools at the base no matter how careful you are, and your roots end up sitting in it.
Pick a pot one size up from the current one, with open drainage holes. A snug fit beats a deep pot every time for your Alocasia Polly.
Depth on its own is not the enemy here. A slightly deeper pot is fine if the width stays snug and the soil drains fast for you. The real problem is total soil volume that the roots cannot reach. So judge a pot by how closely it wraps the root ball, and not by whether it looks tall or short. A pot that grips the roots with a thin margin of soil is your target shape. Width is what you watch, not height.
Material matters a little too. A terracotta pot wicks water out of the soil and dries it faster, which suits a plant this prone to rot. A glazed or plastic pot holds water longer, so you have to water it less often to stay safe. Either works as long as it has drainage holes and fits snug. You just water by feel and check that the top inch of soil has dried before you add more.
Repot only every couple of years, and do it in spring when your plant is putting out new growth. Lift it out, shake off the old mix, and check that the roots have filled most of the pot before you move up at all. Plant it back into a fresh aroid mix of perlite, orchid bark, and a bit of charcoal so water runs right through. Choose a container only slightly larger than the old one. Your Polly grows best a little rootbound, so a small step up keeps it happy and keeps the rot away.
Read the full article: Alocasia Polly Care: A Beginner Guide
