Small indoor plant pots: how to size a cover for a nursery pot

Most houseplants are happiest left in the plastic pot they arrived in. That pot drains, it is the right size for the roots, and lifting it out to water is easier than watering in place. What you buy is a cover: a decorative pot, basket or tin that the nursery pot sits inside. The whole job is getting the cover the right size, and it comes down to two measurements.

Measure the nursery pot, not the plant

Turn the plant round and look at the plastic pot. Nursery pots are made in standard sizes and the size is the diameter across the top rim: 9 cm, 10.5 cm, 12 cm, 13 cm, 14 cm, 15 cm, 17 cm, 19 cm and 21 cm are the common ones in Europe. The number is often moulded into the base. If it is not, measure straight across the rim with a ruler.

Then measure the height from the base to the rim. For most standard pots the height is close to the diameter, so a 12 cm pot is around 11 cm tall and a 14 cm pot around 13 cm. Tall 'rose' pots and squat 'azalea' pots break that rule, which is why it is worth checking.

The two rules for a cover

Width: the cover's inside diameter should be 1 to 2 cm wider than the nursery pot. Less than that and the pot wedges and is hard to lift out; more than 3 cm and it rattles around and the gap shows. Note that product listings give the outside width of a cover, so subtract the wall thickness, roughly 1 cm for ceramic and 1.5 cm for a woven basket.

Height: the cover should be at least as tall as the nursery pot, so the plastic rim is hidden. One or two centimetres taller is ideal. Much taller and the plant sinks into the cover; you can raise it on an upturned saucer, but it is simpler to buy the right height.

A quick size table

• 9 cm nursery pot (herbs, small succulents): cover with an inside width of 10 to 11 cm, at least 9 cm tall.
• 12 cm nursery pot (most supermarket houseplants): cover 13 to 14 cm inside, 11 cm or taller.
• 14 cm nursery pot (pothos, peace lily, small ferns): cover 15 to 16 cm inside, 13 cm or taller.
• 17 cm nursery pot (monstera, larger ferns): cover 18 to 19 cm inside, 16 cm or taller.

What our small planters take

The whitewashed woven bamboo pot is 17 cm across outside and 15 cm high, which suits a 13 or 14 cm nursery pot with the rim just hidden. The grey pot cover with the rope bow is a shade smaller at 16 cm outside and 14.5 cm high, and takes a 12 or 13 cm pot. The whitewashed paulownia pot, sold as a pair, is 17 cm square and 16 cm high, so a 14 cm nursery pot sits inside with a little room.

Low baskets work differently. The 18 cm square cane basket is only 9.5 cm high, so it holds a 9 cm herb pot or a cluster of small succulents rather than a single upright plant. The 27 x 21 cm rectangular basket is 12.5 cm high and takes two 10.5 cm pots or three 9 cm pots in a row, which is how a windowsill herb trio usually ends up.

The double metal bucket planter has two pails on one handle, each sized for a 9 to 10 cm pot. Because the pails are metal with no drainage, lift the plants out to water them and let them drain before they go back.

Watering a plant in a cover

Take the nursery pot out, water it at the sink, let it drain for ten minutes and put it back. If you water in place, the cover fills from the bottom and the roots sit in it, which is how most houseplants die. A woven basket with a plastic liner and a ceramic pot without a hole are both fine as covers for exactly this reason: they never need to drain because nothing is watered in them.

If you would rather skip watering altogether, the same covers take an artificial plant. The faux geranium and lavender tins in the faux botanicals collection come already potted, and single stems can be pushed into a block of floral foam inside any of the covers above.

Repotting: when the cover stops fitting

A healthy houseplant moves up one nursery size every year or two, from 12 to 14 cm, then 14 to 17 cm. Each step up means a new cover or a new home for the old one, which is one argument for buying covers in a family of sizes. Browse the full planters and pot covers collection with the sizes above in hand, and if you are also sizing something for the wall, our wall clock sizing guide uses the same measure-first approach.