Fertilizing Basics for Houseplants

Fertiliser is not plant food in the everyday sense — plants make their own food from light. It is more like a vitamin supplement: useful in the growing season and easy to overdo. 100% Local

What the NPK numbers mean

Every fertiliser label lists three numbers, always in the same order: nitrogen, phosphorus and potassium.

Nitrogen (N): drives leafy green growth.
Phosphorus (P): supports roots, flowers and fruit.
Potassium (K): helps overall vigour and stress tolerance.

A balanced feed such as 10-10-10 suits most foliage houseplants, while flowering plants often do better with a blend higher in phosphorus.

When to feed

Feed during active growth, usually spring and summer when light is strong and new leaves appear. In autumn and winter most houseplants slow down and need little or nothing. Feeding a resting plant can build up salts in the soil and burn roots.

How to dilute and apply

Dilute liquid feed to half or quarter of the label strength for houseplants.
Apply to moist soil, never to a bone-dry pot, to avoid root burn.
Feed every two to four weeks in the growing season, not weekly by default.
Flush the pot with plain water every few months to clear salt buildup.

Which plants need less

Slow growers such as snake plants and ZZ plants.
Succulents and cacti, which need only light, occasional feeding.
Freshly repotted plants, since new mix often already contains nutrients.
Stressed, sick or dormant plants — fix the problem first.

Common mistakes

Feeding on a fixed schedule all year round.
Using full-strength feed on a small pot.
Assuming yellow leaves always mean hunger — often it is overwatering.

Less is usually more. A light, regular feed in the growing season keeps plants healthy without the risk of salt damage.

Frequently Asked Questions

Are fertiliser spikes better than liquid feed?

Spikes release nutrients slowly and are convenient, but it is hard to control how much a plant gets. Liquid feed gives you more control and is easier to dilute for small pots.

What about organic fertilisers?

Compost, worm castings and fish emulsion feed the soil as well as the plant. They tend to be gentler and slower, which suits a low-maintenance routine.

Should I feed a flowering plant more?

Flowering and fruiting plants use more nutrients, so a slightly higher-phosphorus feed during that stage can help. Still dilute it and avoid feeding a dry pot.

Choosing a feed for your plant type

Foliage plants such as Monstera and Pothos do well on a balanced feed. Flowering plants, including African violets and Anthurium, respond to a blend higher in phosphorus when buds form. Herbs and vegetables in containers are heavier feeders than most houseplants, because nutrients leach out with every watering, so they may need feeding every two weeks in the growing season. Slow-growing succulents sit at the other end: a light feed once every month or two is plenty.

General horticultural guidance for planning only. Verify locally.