How to keep a houseplant alive: the five things that actually matter

A plant does not eat soil or fertiliser. It builds itself out of air and water using light, so light is the budget everything else spends from. A plant in too little light cannot use the water you give it, which is why low light and over-watering kill together so often.

Match the plant to the light you have rather than the other way round. If you want a plant in a genuinely dark corner, the honest answers are a snake plant, a ZZ plant, a cast iron plant, or a grow light.

A weekly watering routine ignores the two things that actually change: the season and the weather. The same plant might need water twice a week in July and once a month in December.

Lift the pot instead. A freshly watered pot is heavy and a dry one is noticeably light — after two or three weeks you will read it instantly. Failing that, push a finger two inches into the soil. Wet means wait.

When you do water, water thoroughly until it runs out of the bottom, then tip away whatever collects in the saucer. Little sips leave the lower half of the root ball permanently dry.

A pot without a drainage hole has no way to get rid of excess water, so the roots sit in it and rot. This is the single most common way a healthy plant is killed in its first month, and it is entirely preventable.

If you love a decorative pot that has no hole, use it as a cachepot: keep the plant in its plastic nursery pot, drop that inside, and lift it out to water.

Moving a plant into a much larger pot surrounds a small root ball with a large volume of soil that nothing is drinking from. That soil stays wet, and wet soil with no roots in it is where rot starts.

Go up one size — roughly two inches of extra diameter — and only when the plant is genuinely root-bound.

Most beginner losses come from intervention, not neglect: moving the plant repeatedly, repotting immediately on arrival, fertilising a struggling plant, or watering because it has been a few days. A new plant needs a few weeks in one spot to acclimate.

Fertilise only in the growing season, at half the strength on the bottle, and never as a treatment for a sick plant. Fertiliser is food for a plant that is growing, not medicine for one that is not.

Yellow lower leaves, soft stems, damp soil: too much water. Crispy brown edges with dry soil: too little water, or very dry air. Long leggy growth reaching toward a window with big gaps between leaves: not enough light. Sudden leaf drop after you brought it home: normal acclimation, if the soil and light are right — wait it out.