Choose a pot by its roots, not its flowers

A wide canopy can make a plant look ready for a huge pot. Check the roots before making that decision. A small root system surrounded by a large mass of wet mix may be harder to manage than a modestly enlarged container.

Inspect what is already there

When the plant can be removed safely, support its root ball and slide the nursery pot away. Look for roots occupying the mix, especially a dense circling layer at the outside. A single root through a drainage hole is not enough evidence by itself.

Choose the next size with room for fresh mix around the root ball, using species guidance where available. For a new planting, consider the expected mature size and whether you are growing one plant or a seasonal group.

Consider the job of the pot

Depth, stability, drainage, and weight matter alongside diameter. A tall narrow container can be awkward to move and may have very different moisture conditions at its top and bottom.

After repotting, learn the new drying pattern. The plant has not suddenly acquired roots throughout all the fresh mix. Check both the old root ball and its surroundings, and adjust watering from what you find rather than carrying over a fixed routine from the smaller pot.