Airpot 5.8 liter 18x18x18cm

A 5.8 litre fabric pot, 18 by 18 by 18 centimetres. That is not a rounding: this is a true cube, as wide as it is deep as it is tall, and the only one in our range.

What equal sides do

Check the arithmetic and the size lands exactly: 18 cubed is 5,832 cubic centimetres, so 5.8 litres. There is no taper, no wide rim, no hidden shaping.

In practice that gives you three things. The pot dries back at the same rate on every side, because each wall is the same size and the same distance from the middle. No side dries sooner than the rest, and so no corner where the roots give up.

It also sits flush against its neighbours. Put nine together and you have a 54 by 54 centimetre square with not a centimetre of floor wasted. Round pots leave a gap between every four that you cannot use.

And it stands securely. Eighteen centimetres wide under eighteen tall is a ratio that does not tip, even when the plant grows lopsided or you shift it while full.

Roots at a porous wall

The wall is porous geotextile: air and water pass through it. A root tip reaching the fabric meets air, dries back at the point and stops growing. The plant makes new side roots behind it, which in turn go looking outwards. You build a finely branched mass using the whole block of substrate, rather than a spiral against a smooth wall.

What this size is for

Just under six litres is a size for raising plants and for growing many at once. For a single plant grown on for a long time it is too little: it will empty the pot within a day once the root ball fills it. The 12.5 litre is the next step.

Technical Specifications:

• Volume: 5.8 litres
• Dimensions: 18 x 18 x 18 cm
• Shape: cube, square base
• Material: porous geotextile, black
• Drainage: through base and wall
• Reusable: yes, washable

Frequently asked questions

How many fit on a square metre? Thirty touching. In practice you place sixteen to twenty-five and keep room to water.

Does it need a tray? Yes. Water leaves through the base, so stand it on a tray or a grid and do not let it sit in the run-off.

Does it stand up empty? No, empty it collapses. Filled, the cube holds its shape.

Can I use coco or clay pebbles? Yes, any common substrate. With clay pebbles you water more often, since they hold no water themselves.