What size pot does my plant actually need?

Pot size is measured across the top rim, in inches. A “six inch pot” is six inches across the opening — not six inches tall, and not six inches of soil. Once you know that, most sizing questions answer themselves.

The rule: one to two inches wider

When a plant outgrows its pot, move it up by one to two inches of diameter. For a plant currently in a 6 inch pot, that means a 7 or 8 inch pot — not a 12.

Why bigger is not better

A pot much larger than the root ball holds far more soil than the roots can drain. That soil stays wet for days, the roots sit in it, and they rot. Far more houseplants die of a pot that was too generous than of one that was slightly tight.

When to move up at all

• Roots coming out of the drainage hole.
• Water running straight through, because the pot is more root than soil.
• The plant drying out within a day or two of watering.

None of those on a plant that looks fine? Leave it. Most indoor plants are happy slightly snug.

Measuring what you have

Lay a tape across the top of the current pot, rim to rim. If you are between sizes, take the smaller one — you can always move up next season.

Send us that measurement and we will tell you which listing is the right step up.