Plants in pots can't seek out nutrients the way garden plants can. After a few months in the same compost, nutrients are depleted — and that's when feeding becomes essential.
When to Fertilize
Feed only during the active growing season: March to September in the northern hemisphere. Do not feed in autumn or winter — plants are resting and cannot absorb nutrients, leading to salt build-up and root burn.
Types of Fertilizer
Balanced liquid fertilizer (e.g. 20-20-20) — Good all-rounder for most houseplants. Dilute to half strength and apply every 2–4 weeks.
Slow-release granules — Mixed into soil at repotting. Releases nutrients over 3–6 months. Good for low-maintenance setups.
Specialist formulas — Orchid feed (high potassium), cactus feed (low nitrogen), tomato feed (high potassium, great for flowering houseplants).
NPK Explained
Every fertilizer label shows three numbers (e.g. 5-5-5):
Signs of Overfeeding
White crusty deposits on the soil surface, brown leaf tips, and sudden wilting. Flush soil with water to dilute accumulated salts.
Signs of Underfeeding
Pale or yellowing leaves, slow growth, and small new leaves despite good light and watering.
