Calcium deficiency guide image
Plant deficiency guide

Calcium deficiency

What it looks like: New leaves twist or burn at tips; tomatoes and peppers may develop blossom-end rot.

What it looks like: New leaves twist or burn at tips; tomatoes and peppers may develop blossom-end rot.Organic cure list: Prevention note: Most blossom-end rot comes from moisture swings, not a total lack of calcium.

Quick facts

What it looks like: New leaves twist or burn at tips; tomatoes and peppers may develop blossom-end rot.

Organic cure list:

Prevention note: Most blossom-end rot comes from moisture swings, not a total lack of calcium.

  • Water consistently.
  • Use gypsum where calcium is needed without raising pH.
  • Use crushed eggshells only as a long-term slow amendment.
  • Mulch outdoor crops to stabilize soil moisture.

What to do next

  • Confirm the symptom pattern on new leaves versus older leaves.
  • Check watering, drainage, roots, and pH before adding fertilizer.
  • Start with compost, worm castings, or the gentlest listed organic support.
  • Track new growth for improvement over 1–3 weeks.
  • If the problem continues, test soil or compare with pest and disease signs.

Watch-outs

Do not treat one leaf photo as proof. Nutrient issues often look like watering stress, pH lockout, root damage, heat, cold, or pests.

FAQ

How do I use this plant deficiency guide?

Start with the light, soil, water, symptom, or purpose notes on this page, then make one careful change at a time.

What is the biggest mistake with Calcium deficiency?

Do not treat one leaf photo as proof. Nutrient issues often look like watering stress, pH lockout, root damage, heat, cold, or pests.

When should I get more help?

Get local help if the plant is valuable, symptoms are spreading quickly, or outdoor disease and pest problems may affect nearby plants.