Pots & Trays — Round Pots

The round pot is the standard the rest gets compared to: cheap, stackable, available everywhere and without corners for substrate to pack into. For a single plant that does not have to sit in a tight grid, there is little reason to use anything else.

Two plain sizes

The 10 litre measures 29 cm across by 23 tall and has twelve drainage holes in the base; the 18 litre is 33 by 29.5 cm and is likewise perforated. Those are the two sizes most growers settle on, for a mid-sized and a fully grown plant respectively. Drainage holes are the thing to check here: a pot without them is a bucket, and in a bucket a root mass drowns even when you give exactly enough.

Round with open walls

The six Airmaxx root pots sit on this page as well. They are round in shape but have an open wall structure, so root tips stop at the wall instead of circling. If that effect is specifically what you want, the full range with its sizes is under Airpots; if shape is what matters, they belong here alongside the rest.

Round or square

The difference is your floor. Round pots leave a gap between every four, and across a full tent floor that adds up. With room to spare, round is nicer to work with: easier to turn, easier to lift and no corners for substrate to cake into. With a setup that is full, you get more plants onto the same metre with Square Pots.

Frequently asked questions

Which size for which plant?
Work back from the final size you want rather than from the plant standing there now. Potting on is possible, but each move costs the plant a few days, so a size that lasts the whole cycle is usually the calmer choice.

Do I need a tray under it?
Yes, unless you are on a bench that drains itself. Run-off should not go back into the pot, and the matching sizes are under Plant Trays.

Why do roots circle in the first place?
Because a solid wall gives no signal to stop. The root follows the wall and keeps growing without reaching new substrate, so the plant makes more and more root without gaining from it.