In short: don’t water on a schedule, water when the plant needs it. For most common houseplants that means when the top few centimetres of soil are dry; for succulents and cacti, when the soil is dry all the way through; for ferns and other moisture-lovers, before the surface dries out. How long that takes changes with the season, the light, the pot and the plant.
Why a fixed schedule fails
“Water once a week” sounds simple, and it is the reason so many houseplants die. How fast a pot dries out depends on:
- Light and warmth. A plant in a bright, warm window uses water far faster than the same plant in a cool corner.
- The season. Most houseplants grow in spring and summer and slow down in winter. The same plant can need water every few days in July and every few weeks in January.
- The pot. Terracotta breathes and dries quickly; plastic and glazed pots hold water. A small pot dries faster than a big one.
- The soil and the plant. Chunky, airy mixes drain quickly; dense soil stays wet. A plant that has filled its pot with roots drinks more.
- Indoor heating and humidity. Radiators and dry winter air speed things up; a steamy bathroom slows them down.
A schedule ignores all of this. Overwatering is one of the most common ways houseplants die: roots sitting in wet soil can’t breathe, and they rot.
How to tell when a plant needs water
- The finger test. Push a finger into the soil. For most leafy houseplants, water when the top 2–3 cm (about an inch) feel dry.
- Lift the pot. A watered pot is noticeably heavier than a dry one. After a few weeks you can tell by weight alone.
- Look at the soil and the leaves. Soil pulling away from the edge of the pot means very dry. Drooping leaves can mean thirst, but also too much water, so check the soil before reaching for the watering can.
A rough guide by plant type
| Plant type | Examples | When to water |
|---|---|---|
| Succulents and cacti | aloe, echeveria, jade plant | When the soil is completely dry. Very little in winter. |
| Tough foliage plants | snake plant, ZZ plant | When the soil has mostly dried out. They forgive neglect, not wet feet. |
| Common leafy plants | pothos, monstera, philodendron | When the top 2–3 cm are dry. |
| Moisture-lovers | ferns, calathea, peace lily | Keep the soil evenly moist; water as the surface starts to dry. |
| Outdoor pots | balcony and patio plants | Check often in hot or windy weather; skip after real rain. |
These are starting points. Every plant in your home will settle into its own rhythm.
How to water
- Water thoroughly, until water runs out of the drainage holes, so the whole root ball gets wet.
- Empty the saucer after a few minutes. A plant standing in water is the classic cause of root rot.
- Use pots with drainage holes. A decorative pot without holes is fine as an outer cover, but keep the plant in a pot that drains inside it.
- Water less in winter, and feed only in the growing season; a resting plant doesn’t need fertiliser.
Outdoor plants and the weather
Outdoor pots dry out much faster in sun and wind, and they need almost nothing after a good rain, unless they are under an overhang where the rain doesn’t reach. Checking the forecast before you water saves both water and roots.
How PlantCoach helps
PlantCoach is an iPhone app built around the daily question: does anything need water today? Instead of a reminder per plant, it gives you one answer a day for each plant: water today, or skip.
- A starting interval for each plant. Add a plant by photo or by name, and it gets the watering interval from its care guide (61 plants have their own; others get the guide for their type). The count starts from the day you last watered it.
- Weather-aware outdoor plants. Plants tagged outdoor also read the Apple WeatherKit forecast and skip a watering when rain is likely.
- It works from what really happened. Log a watering, or backdate one, and the next answer starts from the real date. Tap “Not today” on a reminder and PlantCoach learns to wait a little longer for that plant.
- Water a whole room at once. When more than one plant in a room is due, one button opens a sign-off ticked for exactly those plants.
- Feeding with a rest season, paused through the dormant months.
PlantCoach doesn’t measure soil moisture, and it doesn’t know how bright your window is, so treat its answer as the prompt to check, not the final word: if the soil says otherwise, trust the soil and log what you did. The daily digest is the only notification, with an optional evening one. PlantCoach is free for up to five plants, and your plants sync only through your own iCloud.
Common questions
How often should I water a monstera?
When the top 2–3 cm of soil are dry. In a bright, warm room in summer that can be about once a week; in winter, often every two to three weeks. Check the soil rather than the calendar.
Is it better to underwater or overwater a houseplant?
For most houseplants, slightly too dry is safer than too wet. A thirsty plant usually recovers after a good drink; roots that have rotted in wet soil often don’t.
Should I water houseplants less in winter?
Yes. Most houseplants grow slowly in winter, with less light, and use much less water. Check the soil before each watering; the gaps often stretch to several weeks.
Why are my plant's leaves drooping if the soil is wet?
Drooping with wet soil usually means too much water: the roots are struggling to breathe. Let the soil dry out more before the next watering, and make sure the pot drains.
Do outdoor potted plants need watering after rain?
Usually not after a good rain, unless the pot sits under an overhang or the leaves shed the rain away from the soil. In hot or windy weather they can dry out again within a day or two.