How to Fertilize Your Plants (Without Burning Them)

In a pot, a plant only has the nutrients you give it: the soil runs out in a few months. Fertilizing well is the difference between a plant that survives and one that grows strong and blooms. The good news is it's easy once you grasp the basics — and the biggest mistake is overdoing it.

Understand NPK

Every fertilizer has three numbers (e.g. 7-3-6). They're the main nutrients:

• N (Nitrogen): leaves and green growth.
• P (Phosphorus): roots, flowers and fruit.
• K (Potassium): overall health, flowering and fruiting.

For foliage plants (pothos, monstera), look for more N. For flowers and fruit (tomatoes, orchids), more P and K.

How often to fertilize

The golden rule: only during the growing season (spring and summer).

• Houseplants: every 2-4 weeks in spring-summer, at half strength.
• In fall-winter, don't fertilize (or very little): the plant is resting and fertilizer builds up and burns the roots.

Types of fertilizer

• Liquid: the easiest to dose; you dilute it in the watering can.
• Slow-release granules: apply once and it lasts months. Convenient.
• Organic (worm castings, compost): gentle and hard to burn; ideal for the garden.

The golden rule: less is more

It's far easier to harm a plant by overfeeding than by underfeeding. Always start with half the dose the label suggests.

Signs of overfeeding

• Brown, burnt tips and edges.
• A white salt crust on the soil surface or pot rim.
• Weak growth despite heavy feeding.

If you overdo it, water heavily (without fertilizer) a few times to flush out the excess salts.

When NOT to fertilize

• Newly bought or freshly repotted plants (wait 3-4 weeks).
• Sick or stressed plants: fix the problem first.
• In deep winter.

With half strength, in the right season and no rush, your plants will reward you with strong leaves and more flowers. Unsure about a plant? Try the AI diagnosis.