Diagnosing and Treating Pale Foliage on Garden Plants

A gardener named Rick noticed that the right side of a plant in his garden had turned pale over several months, while the left side retained its normal color. He asked for possible causes and remedies.

Possible Causes

Several factors can cause one-sided paling: vole damage to roots, soil-borne diseases, stem diseases, or drainage issues that affect only part of the root zone. Without seeing the plant in person, it's impossible to pinpoint the exact cause, but the most common culprits are soil diseases and poor drainage.

Recommended Action Plan

1. Apply a soil fungicide. Visit a local garden center and pick up a product labeled for soil disease control. A reliable choice is Agri-Fos by Monterey, though your local expert may suggest an alternative.
2. Spray liquid iron on the foliage. Iron absorbed through the leaves bypasses soil problems and can green up the plant quickly.
3. Pull back mulch. Keep mulch away from the trunk and allow the soil surface to dry faster. Mulch touching the trunk during the growing season encourages rot and disease.

What to Expect

If the treatment addresses the underlying issue, you should see improved color and vigor within 2–3 weeks. If there's no improvement, further diagnosis will be needed.