Teral

Plant doctor · WITH DR. COCO

Why are leaves turning yellow in cocopeat?

Before adding feed, ask where the yellowing began. Older leaves, new leaves and whole-plant yellowing provide different clues, but none confirms a cause on its own.

Teral grower guidance · Updated 27 October 2026

Dr. Coco, Growlab character guideDr. CocoYour plant doctor guide

THE COCOPEAT CONNECTION

Why the root zone matters

In coir, root health and the nutrient solution matter together. A plant may struggle to take up nutrients even when fertiliser is present.

01 / OBSERVE

Three checks before you change anything

  1. Photograph the whole plant and both older and newer leaves. Note whether veins remain green or leaf edges are damaged.
  2. Inspect roots and moisture conditions. Compare with an unaffected plant in the same crop.
  3. Check calibrated pH and EC results against the crop’s targets and test method. Record recent fertiliser or water changes.

02 / NARROW IT DOWN

Where did yellowing start?

Choose the closest observation for a suggested next check.

Mostly older leaves

Record the pattern and rate of spread. Review feeding and root health; gradual ageing of a few lower leaves may be normal.

Mostly new leaves

Check root-zone pH and recent growth with your adviser. A leaf pattern alone cannot tell you which nutrient to add.

Whole plant or sudden wilting

Check water delivery and root condition promptly. Escalate rapid decline rather than repeatedly increasing fertiliser.

03 / TAKE THE NEXT STEP

Leave with something useful

Prepare photos, crop stage, root observations and recent pH/EC readings. Consider tissue and substrate analysis if the cause remains unclear.

Keep in mind

More fertiliser can increase salts without resolving the underlying cause.

Discuss this with Teral →

Watch the related Growlab lessons

The written checks above stand on their own. These short lessons add context.

Lesson links selected from Growlab’s supplied transcript and description review.

Further technical reading

Purdue Extension · Measuring substrate pH and EC ↗