How Often Should You Water? Watering Plants in Pots Indoors

More potted plants are killed by too much water than by too little. Roots need air as much as they need water, and a pot that never dries back slowly suffocates them. The good news is that watering well is not about a schedule at all. It is about checking the pot before you water, giving enough to see a little run-off, and then letting it dry back before the next drink. This guide shows you how to judge each of those steps, how the medium and pot change the answer, and when it is worth automating the job.

Why too much water is the bigger danger

Every pore in the medium holds either water or air. Straight after watering most of them hold water. As the plant drinks and the surface dries, air is pulled back in behind it. That cycle, wet then drier, is what keeps roots healthy: they take up water and nutrients while it is wet, and they breathe while it dries back.

Water again before the pot has dried back and the air never returns. Roots starved of oxygen stop growing, then start to die, and the plant can no longer take up the water that is all around it. That is why an overwatered plant wilts in a soaking wet pot. Dead and dying roots also invite root rot and fungus gnats, which is why our fungus gnats guide starts with watering habits.

Underwatering is easier to spot and usually easier to fix: the plant goes limp, you water it, and within a few hours it stands up again. Overwatering creeps up over days and is often mistaken for a feeding problem.

How to tell when a pot needs water

Forget the calendar. The same plant can need water every day in a warm week and every four days in a cool one. Check the pot instead, using one or more of these.

1. Lift the pot. This is the most reliable check and costs nothing. Lift a pot straight after a good watering so you know what heavy feels like, then lift it each day. When it feels clearly lighter, it is ready. With practice you can judge it within a second. For pots too big to lift, tip them slightly and feel the weight.
2. Feel the medium. Push a finger a few centimetres into soil. If it is dry at the first knuckle, the pot is usually ready. The surface alone is misleading: it dries long before the middle of the pot, especially under a light or a fan.
3. Use a moisture meter. A probe meter gives you a number instead of a feeling, which helps if you are new to it or several people share the watering. Take readings from the middle of the pot, not just the edge, and learn which reading your pots sit at just before you would have watered by weight.
4. Watch the plant, last. Drooping leaves tell you something is wrong, but by the time the plant shows it, the pot is already too wet or too dry. Use the plant to confirm, not to decide.

Meters and sensors that take the guesswork out

Overwatered or underwatered? How to tell

Both make a plant droop, which is why they are so often confused. Check the pot before you act: the weight of the pot settles it almost every time.

If the plant is overwatered, the fix is patience: stop watering, empty any saucer, increase air movement around the pots and wait until the pot is genuinely light before you water again. If it keeps happening, the pot is probably too big for the plant or the medium drains too slowly; our pot size guide covers both.

Yellowing on older leaves can also be a nutrient problem. Get the watering right first, then see our nutrient deficiencies guide if it carries on.

How much water to give

The aim is to wet the whole root ball every time, not to give a fixed amount. A small splash that only wets the top few centimetres leaves the lower roots dry, and over time salts from the feed build up in the bit that never gets rinsed.

• Water until you see run-off. For soil and coco, keep going until roughly 10-20% of what you pour runs out of the drainage holes. Pour 2 litres and see about 200-400ml come out, and you have it about right.
• Measure it once. Use a jug for the first few waterings and note how much each pot takes to reach run-off. After that you will know roughly what each size needs.
• Then wait. The amount you give stays roughly the same; the gap between waterings is what changes as the plant grows, the weather warms and the roots fill the pot.

Watering by growing medium

The medium decides how much air is left after watering and how fast the pot dries back, so it changes the routine more than anything else. Our growing media guide compares them in detail; this is how each one waters.

In soil and compost, most of the feed is in the medium, so you can often water with plain water between feeds. In coco and hydro the medium holds almost nothing, so most growers feed at every watering at the strength set out in our coco feeding guide. Either way, check the pH of what you pour: our pH guide gives the target for each medium.

The pot matters too. Fabric pots and air-pruning pots let air in through the sides, so they dry back faster and are much harder to overwater than a solid plastic pot of the same size. Expect to water them more often, and to see more surface evaporation in a warm tent.

Pots and media that drain freely

How to water a pot properly

1. Check first. Lift, feel or measure. If the pot is still heavy, walk away.
2. Use water at room temperature. Roughly 18-22°C, the same range as our root zone guide. In winter, water from a cold outside tap can be close to freezing, so fill a container and let it stand indoors first.
3. Pour slowly, all the way round. Water poured fast into one spot finds the quickest path down and out, and the rest of the pot stays dry. Move round the pot and give it in two or three stages, pausing for a minute between each so the medium can soak it up.
4. Stop at run-off. Roughly 10-20% out of the bottom, as above.
5. Empty the saucer. Within about half an hour, tip out or soak up what has collected. A pot left standing in its own run-off can draw it back up and stay waterlogged.

If your tap water is very hard, chlorinated or variable, our water quality guide explains when it is worth filtering. For a tent full of pots, a hose with a long lance saves carrying cans and lets you reach the back row without moving anything.

Watering kit

When a pot will not take water

Peat-based compost and coco that dry right out can shrink away from the sides and start to repel water. You pour it in and it runs straight down the gap and out of the bottom, so the pot looks watered but is still dry in the middle. Water in small amounts with pauses between, or stand the pot in a tray of water until it is heavy again, then drain it. After that, water before it gets that dry.

Drainage, saucers and run-off

Good watering depends on the water having somewhere to go. Every pot needs drainage holes, and every pot inside a tent or on a floor needs something underneath to catch the run-off.

• Saucers under individual pots catch the run-off; empty them after each watering.
• Trays under a group of pots make emptying quicker and keep the tent floor dry. Raise the pots a little on blocks or an upturned saucer so they are not sitting in what drains out.
• A catchment tray under the whole tent or reservoir is cheap insurance against a split pot, an overflowing saucer or a leaking fitting.

Standing run-off also raises humidity in a closed tent and gives fungus gnats somewhere to breed; our humidity guide covers the rest of that picture.

When to automate watering

Hand watering is the best way to learn how your plants drink, and for a few pots it is all you need. Automation earns its place when you have many pots, are away for days at a time, or grow in coco or clay pebbles that need water more than once a day.

• Gravity-fed trays such as AutoPot feed each pot from below through a valve, with no pump or power. The plant takes what it needs from the tray, which suits soil and coco alike. Our AutoPot buying guide compares the sizes.
• Drip systems deliver a measured amount to each pot from a reservoir, switched by a timer. They suit coco, rockwool and clay pebbles, where small frequent irrigations work best. See our drip and flood and drain buying guide.
• Self-watering seed trays wick water up into each cell, which keeps seedlings evenly moist without daily attention.

Automation still needs checking. Lift a pot or take a meter reading every day or two to make sure the system is giving what you expect, keep drippers and lines clean, and watch the reservoir level. Our hydroponic systems guide explains how each type works.

Shop pots, trays and irrigation

Eight watering mistakes to avoid

1. Watering on a schedule. Every Monday and Thursday ignores the weather, the plant's size and the pot. Check first, every time.
2. Little and often in soil. Daily splashes keep the top wet and the bottom dry, and the pot never breathes. Water thoroughly, then wait.
3. Letting coco dry out. Coco is the opposite: it is forgiving of frequent watering and unforgiving of drying out.
4. A small plant in a huge pot. The medium stays wet far longer than the roots can use. Pot on in steps.
5. Leaving pots in their run-off. Empty the saucers.
6. Judging by the surface. The top dries first, especially under a light or a fan. Lift the pot.
7. Ice-cold water. Let it come up to room temperature first.
8. Treating every droop as thirst. A heavy pot with a drooping plant needs less water, not more.

Quick answers

How often should I water plants in pots?

There is no fixed schedule. Water when the pot needs it, not by the calendar. Lift the pot, check the top few centimetres of the medium or use a moisture meter, and water when it has dried back. In a warm tent a large soil pot might need water every two to four days, while an established plant in coco often wants water once a day or more.

How do I know if I am overwatering?

The medium stays wet for days, the leaves droop even though the pot is heavy, lower leaves turn yellow, growth slows and fungus gnats appear on the surface. Underwatered plants look limp too, but the pot feels light and they perk up within hours of a drink.

How much water should come out of the bottom of the pot?

For soil and coco, aim for roughly 10-20% of what you pour in to run out of the drainage holes. That shows the whole root ball is wet and stops salts from building up. Then empty the saucer rather than letting the pot stand in the run-off.

Is it better to water from the top or the bottom?

Top watering is the standard for most pots because it wets the whole medium and lets you see run-off. Bottom watering, standing a tray or small pot in water for a short while, suits seedlings and very dry pots that have started to shed water. Self-watering pots and AutoPot-style trays feed from below all the time.

Should I let the pot dry out completely?

No. Let it dry back, not dry out. Soil should become noticeably lighter and dry in the top few centimetres before you water again. Coco should never dry out completely, so it is usually watered more often. A pot that dries to dust can shrink away from the sides and become hard to rewet.

What temperature should the water be?

Use water close to room temperature, roughly 18-22°C, the same range we recommend for the root zone. Very cold water straight from an outside tap in winter can chill the roots, so let it stand indoors first.

Why does water run straight through my pot?

The medium has dried so far that it has shrunk from the sides, and water is running down the gap instead of soaking in. Water slowly in small amounts, pause between each, or stand the pot in a tray of water for a while until it is heavy again. Then avoid letting it dry that far.

Is this the same for tomatoes, chillies and houseplants?

Yes. Tomatoes, chillies, herbs, salad leaves and houseplants in pots all need the same thing: water when the pot has dried back, enough to see a little run-off, and good drainage. Nothing here depends on what you are growing.