Diagnosing Leaf Drop and Yellowing on Bell Pepper Plants

Common Causes of Sudden Leaf Loss

When pepper plants lose leaves that turn yellow with brown spots—especially early in the season—the cause is often a fungal or bacterial disease, or root-related stress. If the plant was recently purchased, the problem may have originated at the nursery.

Immediate Steps

• Consider returning the plants. Reputable garden centers will often diagnose the issue and offer a replacement or refund.
• Inspect roots. Gently remove one plant from its pot; look for brown, mushy roots (root rot) or white fungal growth.
• Assess the growing conditions. Overwatering, poor drainage, and cold snaps can all trigger leaf drop.

Can the Plants Recover?

If only a few leaves remain at the top, recovery is unlikely this season. In Southern Ontario, the growing season may be too short for a severely defoliated plant to regrow and set fruit before frost. However, a larger, healthy transplant could still produce a modest crop if planted promptly.

Prevention for Next Season

• Buy from trusted local growers.
• Harden off transplants gradually.
• Use well-draining soil and avoid overhead watering.
• Rotate crops; don’t plant peppers in the same spot year after year.

When in doubt, consult your local extension service or nursery with a sample—they can identify specific pathogens and recommend targeted treatments.