Nutrient deficiency

What it looks like

New leaves are smaller and paler than old ones. Growth has slowed or stopped. Veins stay green while the tissue between them yellows (chlorosis).

Why it happened

The plant has been in the same substrate for years and the nutrients are spent, or it is never fed during the growing season.

What to do

1. Feed with a liquid houseplant fertiliser roughly every 2–3 weeks from March to September. 2. Dilute to half the recommended dose — over-feeding burns roots. 3. Never feed into dry soil; always water first. 4. If the plant has been in the same pot for over two years, repot it. 5. Do not feed at all in winter.

How to prevent it

Repot into fresh substrate every 1–2 years. That often replaces feeding entirely.

Most common on these species

• Gardenia
• Lemon tree
• Petunia
• Rhododendron
• Indoor azalea
• Camellia
• Hydrangea