How do I keep houseplants alive?

The four things houseplants actually need — light, water, drainage and the right pot size — and how to diagnose an unhappy plant.

Difficulty: beginner
Time: 20 min
Read: 3 min

Short answer

Match the plant to the light you actually have, water only when the top few centimetres are dry, and make sure every pot drains. Most houseplant deaths are overwatering, insufficient light, or both — and the symptoms overlap, which is why people water a struggling plant that's already drowning.

Houseplants have a reputation for being difficult that mostly comes from a mismatch between the plant and the room. A plant that needs bright light will slowly decline in a dark corner no matter how well it's watered, and no amount of care compensates. Choosing for the conditions you have is most of the work.

What you'll need

Pots with drainage holes
Appropriate potting compost
Watering can
Saucers or cache pots (optional)

Step by step

Assess the actual light in the spot before choosing a plant.A north-facing room is low light even if it feels bright. Two metres back from a window is a fraction of the light at the sill.
Choose plants that suit that light rather than trying to change the room.Low light: pothos, snake plant, ZZ plant, aspidistra. Bright indirect: monstera, calathea, most ferns. Direct sun: cacti and succulents.
Make sure every pot has drainage holes.Decorative pots without holes are the single most common cause of root rot. Use them as a cache pot with a plastic inner pot inside.
Water only when the top 3–5cm of compost is dry.Push a finger in. Most houseplants are killed by watering on a schedule regardless of need.
Water thoroughly until it drains from the bottom, then empty the saucer.Thorough then dry beats little and often. Standing water rots roots.
Reduce watering substantially in winter.Lower light and cooler temperatures mean much slower growth and much less water use. Winter overwatering is very common.
Feed during the growing season only — spring and summer — at half the stated strength.Feeding a dormant plant in winter causes salt build-up in the compost.
Repot when roots emerge from the drainage holes, going up only one pot size.Too large a pot holds too much wet compost around a small root ball, which rots.

Tips

Wipe dust off leaves occasionally. It genuinely reduces the light a plant receives, particularly on large-leaved plants.
Rotate pots a quarter turn each time you water so growth stays even rather than leaning to the window.
Most houseplants come from humid environments and struggle next to radiators. Grouping plants raises local humidity more effectively than misting does.
If a plant is declining and you're not sure why, check the roots. Healthy roots are firm and pale; rotted roots are brown, soft and smell.

Common mistakes

Watering on a schedule — Plant needs vary with season, light and temperature. Check the compost instead.
Pots without drainage — Water collects at the bottom and rots the roots. The most common houseplant killer.
Repotting into a much bigger pot — The excess wet compost around a small root ball stays soggy and causes rot.
Blaming watering for a light problem — A plant in insufficient light declines slowly whatever you do. Move it or change the plant.

Questions people ask

Why are my plant's leaves turning yellow?

Most often overwatering, particularly if it's the lower leaves and the compost is wet. It can also be underwatering, insufficient light, or simply an old leaf being shed. Check the compost first.

Which houseplants are hardest to kill?

Snake plant, ZZ plant, pothos and aspidistra tolerate low light, irregular watering and general neglect better than almost anything else.

Should I mist my plants?

Misting raises humidity only momentarily and doesn't achieve much. Grouping plants, using a pebble tray, or a humidifier are all more effective for humidity-loving plants.