How to Water Houseplants

If you’ve lost a houseplant, the odds are good that it was too much water. Clemson University’s Home & Garden Information Center calls overwatering the main cause of death of potted plants: roots need both water and oxygen, and roots surrounded by water cannot take up oxygen, so they may rot. The cruel twist, as Clemson notes, is that the symptoms of overwatering and underwatering are similar.

This guide covers when to water, how to water properly, and how to help a plant that is already sitting in soggy soil, following Clemson, the University of Illinois Extension and the University of Maryland Extension.

Why “once a week” is bad advice

Clemson’s answer to “how often should I water?” is that there is no set answer. The University of Maryland notes that too many people assume once a week is the right interval. How fast a plant uses water depends on:

The plant. Plants with large or very thin leaves, or fine surface roots, usually need water more often than succulents with fleshy leaves and stems that store water (Clemson).
Growth stage. A plant needs less water while it is dormant and when growth slows after a flush of new leaves or heavy flowering (Clemson).
Location. A plant in a warm, dry, sunny spot needs water more often than one in a cool spot with low light (Clemson).
Pot. Water evaporates quickly through the sides of a porous clay pot, so it needs watering more often than a glazed or plastic pot, and a large plant in a small pot needs water more often than a small plant in a large pot (Clemson).
Potting mix. Heavy, fine mixes and mixes with a lot of peat hold more water than loose mixes with bark, sand and perlite (Clemson).

Water the plant, not the calendar - the University of Illinois puts it the same way. If you want a personalised starting point, our watering calculator factors in the plant, pot and light.

The one rule: check the soil first

Before every watering, check the mix. Ways the extension services suggest:

The finger test. The University of Illinois suggests testing the soil with your finger to a depth of two inches (about 5 cm); if it is dry, the plant probably needs water. Clemson suggests pushing a finger in up to the first joint.
Lift the pot. Dry mix weighs less. The University of Maryland suggests lifting the pot just after a thorough watering and again over the following days to learn the difference.
Tap a clay pot. Clemson notes that drying mix shrinks from the sides of a clay pot: a dull sound when you rap the pot means moist soil, a hollow one means it needs water.
Look at the colour. Potting mix turns from dark to lighter as it dries (Clemson).
A stick in a big pot. Push a stick or dowel to the bottom of a large pot: moist soil sticks to it or discolours it slightly (University of Maryland).

Moisture meters exist, but Clemson notes they vary widely in accuracy and their readings can be affected by fertiliser and soil type; the University of Illinois calls them useful but not always reliable.

How dry should it get?

It depends on the plant, so look up each species. The University of Illinois describes three typical labels: soil kept constantly moist but not soggy, soil allowed to dry moderately between waterings, and soil kept very slightly moist at all times, with succulents and cacti following their own cycle. Clemson notes that the snake plant is prone to rotting if overwatered. Each Plantvale plant profile, such as calathea, lists its own watering needs.

How to water properly

When it is time to water, do it thoroughly:

Water until it runs out of the bottom of the pot. Clemson explains that this washes out excess salts and makes sure the bottom two-thirds of the pot, where most of the roots are, gets enough water.
Empty the saucer. Don’t let the pot sit in the water that runs out (Clemson, University of Illinois). The University of Maryland adds that standing water in saucers invites fungus gnats and other insects.
Use room-temperature water. Clemson advises against hot or cold water and gives 62-72 °F (about 17-22 °C) as the range.
Avoid softened water. Clemson and the University of Illinois both advise against it; Clemson explains that it adds sodium and chloride to the mix.

Top watering vs bottom watering

Bottom watering, which the University of Illinois calls sub-irrigation, means standing the pot in a few inches of water in a sink or saucer and taking it out once moisture has wicked up to the top of the mix. It is also how Clemson suggests rewetting a mix that has dried out hard: water once and again half an hour later, or stand the pot in a sink or bucket of water until the surface is moist, then let it drain completely. Top watering that runs through the pot also flushes out excess salts (Clemson).

Overwatered or underwatered? How to tell

Both can look like a sad, drooping plant. Clemson warns that wilting is often a sign the plant needs water, but not always: root rot from too much water also stops a plant taking up water, and then watering makes things worse. The University of Maryland notes the main sign of excess water is wilting or yellowing of the lower and inner leaves, and that root rot can make a plant wilt even in wet soil.

The decisive test: feel the mix. Drooping with wet mix points to overwatering; drooping with dry mix points to thirst.

How to help an overwatered plant

If you catch it early:

Stop watering and let the mix dry before watering again.
Empty any saucer or outer pot so the plant is not standing in water.
If the mix stays wet, check the roots. Clemson describes rotted roots as brown to black and possibly soft. If only a few roots are affected, cut them out and repot the plant in sterile potting mix; if most roots are dark, soft and dead, Clemson says it is better to discard the plant.

Drainage: the non-negotiable

Water that cannot drain away keeps the roots short of oxygen. Two rules:

Use a pot that drains, and never leave it standing in water. If you love a decorative pot with no hole, keep the plant in a plain nursery pot inside it and lift it out to water and drain.
Match the mix to the plant. Loose mixes with bark, sand and perlite hold less water than heavy, peat-rich mixes (Clemson).

Frequently asked questions

How often should I water my houseplants?

There is no fixed answer: it depends on the plant, its growth stage, its spot, the pot and the mix (Clemson). Check the mix before every watering; the University of Illinois suggests a finger test to two inches.

Should I water houseplants more in summer or winter?

Usually less in winter. Clemson notes plants need less water while dormant or when growth slows, and the University of Maryland suggests letting most of the mix dry out in winter, “like a freshly wrung out dish towel”, not bone dry.

Can I use tap water for houseplants?

For most plants, yes. Clemson notes that some houseplants are sensitive to fluoride or chlorine in tap water, and that brown leaf tips can also come from hot, dry air, uneven watering and salt build-up. Avoid softened water (Clemson, University of Illinois).

My plant is droopy but the soil is wet - what’s wrong?

That points to overwatering and possible root rot. Stop watering and check the roots if the mix stays soggy.

Is bottom watering better than top watering?

Both work. Bottom watering helps rewet a dried-out mix; thorough top watering flushes salts out of the pot (Clemson, University of Illinois).

Sources

Clemson University Home & Garden Information Center, Indoor Plants: Watering and Houseplant Diseases & Disorders. Read 28 October 2026.
University of Illinois Extension, Watering (houseplants). Read 28 October 2026.
University of Maryland Extension, Overwatered Indoor Plants and Winter Indoor Plant Problems. Read 28 October 2026.

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