Gardening glossary
Root-bound
A plant becomes root-bound when its roots have grown to fill the available pot volume and started circling the inside of the container in search of more room. Eventually the roots dominate the pot so completely that there's almost no soil left to hold moisture or supply nutrients.
How to tell your plant is root-bound:
- **Roots visible at the surface** or growing out the drainage holes. - **Water runs through almost instantly.** Healthy soil holds water for 30+ seconds before it drains out the bottom; a root-bound pot drains in 5–10 seconds because there's no soil left to absorb it. - **The plant dries out faster and faster.** Going from weekly to every-three-days watering with no other changes is a classic sign. - **Stalled growth** despite proper light, water, and feeding. - **Slip the plant out of the pot.** If the root ball holds the pot's exact shape and you see a dense mat of circling roots, it's root-bound. A few visible roots is normal; a solid mat is not.
Some plants tolerate being root-bound and even bloom better for it — peace lilies, spider plants, snake plants, and clivia all flower more reliably when slightly crowded. Most other species (monstera, pothos, fiddle-leaf fig, philodendron, vegetable seedlings) suffer.
To fix, pot up one size — typically 1–2 inches wider in diameter, not larger. Going from a 6-inch to a 12-inch pot creates a giant volume of wet soil the small root ball can't dry out, which leads to root rot. Loosen the outer roots gently before placing in the new pot. If roots are tightly matted, score the root ball with a clean knife in three or four vertical cuts — this looks brutal but encourages outward growth into the new soil.
Repot in spring when the plant is gearing up to grow. Water lightly for the first week to let the disturbed roots recover.