Watering houseplants: how often and how much?

Watering a houseplant may seem like the simplest part of its care, but this is where things most often go wrong. More houseplants die from overwatering than from underwatering: the roots sit in wet soil for too long, no longer receive oxygen, and begin to rot. At the same time, there are species that start to droop after just a few days of dryness. So there is no standard answer to the question "how often and how much?", but there is a consistent approach that works for every plant.

In this guide you will read why a fixed watering schedule does not work, how to tell in a few seconds if your plant is thirsty, how often the best-known houseplants need water and how much you give each time. You will also read how to water less in autumn and winter and how to recognize too much or too little water in time.

Why a fixed watering schedule does not work

Many people water their plants every Saturday, whether they need it or not. But a plant does not drink according to the calendar. How quickly the potting soil dries out depends on light, temperature, the size of the plant, the material of the pot and the season. The same plant can be dry after four days on a sunny windowsill in July and not until after three weeks away from the window in December.

Light is the most important factor: the more light, the faster a plant grows and the more water it evaporates. A plant in a dark place therefore needs much less, as is also evident from our blog about houseplants for low light. So use a fixed day at most to check. How to assess light and warmth in a place, you can read on our page about locations.

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This is how you see if your houseplant needs water

You do not need to be an expert to see if a plant is thirsty. With these two checks you will know within a few seconds.

The finger test

Stick your finger two to three centimeters deep into the potting soil. If it still feels cool and moist there, then wait. If it is dry and crumbly, then it is time to water for most houseplants. For large pots, it is better to stick a wooden skewer halfway into the pot: if it comes out clean and dry, then the soil is dry deeper down.

The weight of the pot

Lift the pot immediately after watering and again a week later: wet soil is much heavier than dry soil, and after a few times you will feel the difference immediately. Moreover, if the soil pulls away from the pot edge and is lighter in color, then it is well dried.

How often do you water which houseplant?

Houseplants fall roughly into three groups, which differ in how dry the soil is allowed to get.

Plants that can dry out completely

Succulents, cacti, Aloe vera, Sansevieria and Zamioculcas store water in their leaves, stems or rhizomes. Only water them when the soil is completely dry; usually once every two to three weeks in summer, even less in winter. If in doubt, wait another week: these plants recover easily from drought, but hardly from rot. The Zamioculcas is the strongest example of this.

Plants whose top layer may dry out

The largest group: Monstera, Ficus, Philodendron, Epipremnum, Dracaena, Pachira, palms and Peperomia. Water when the top two to five centimeters are dry. In summer that is often once every week to ten days, in winter once every two to three weeks. Peperomias have fleshy leaves and can stand dry a little longer than the rest of this group.

Plants that want to remain slightly moist

Ferns, Calathea, Maranta, Spathiphyllum and Alocasia do not like to dry out. Keep the soil slightly moist, but never soaking wet, and water as soon as the top centimeter feels dry. A Calathea quickly gets brown leaf edges and curled leaves with too little water; a Spathiphyllum hangs visibly limp and stands upright again within a few hours after a good drink.

Overview: when do you water which plant?

The frequencies below are guidelines for a plant in a pot of 12 to 20 centimeters in a bright place. Always check the soil first: that determines the timing, not the table.

For the plants in our houseplant collection, the product page states how much water each species needs. You can find a more detailed explanation per situation on our page about watering.

How much water do you give each time?

Enough so that all the soil gets wet, and then nothing more until the soil is dry enough again. A splash every few days only wets the top layer, while the roots at the bottom remain dry. So it is better to water less often and then thoroughly.

Watering from above

Water slowly and all around on the soil, not into the heart of the plant, until water runs out of the drainage hole. Let the pot drain for a quarter of an hour and then pour out the water from the saucer or decorative pot. For a plant of 12 centimeters, one or two glasses are often enough; a large plant in a pot of 30 centimeters can easily need two liters.

Watering from below

Place the nursery pot half an hour in a basin with a few centimeters of water. The soil absorbs the water through the drainage hole, so that the roots are evenly wet and the leaf remains dry. Orchids in bark you dunk in the same way for about ten minutes. Always let the pot drain well afterwards.

What water do you use?

Use water at room temperature; cold water can give tropical plants a shock. Tap water is fine for most houseplants. Lime-sensitive species like Calathea benefit from rainwater or tap water that has stood overnight. Do not use water from a salt water softener, because the sodium accumulates in the soil.

Pot and drainage: the basis for good watering

No matter how well you water, it will still go wrong in the wrong pot. A container without a hole, such as a teapot or bowl, looks nice, but water that the plant does not absorb remains at the bottom. The roots rot there, often without you seeing it on the outside.

The safest combination is a nursery pot with drainage holes in a decorative pot without a hole. Check after a quarter of an hour if there is water in the decorative pot, or lift the nursery pot out for a moment to let it drain. A layer of hydro beads at the bottom of the decorative pot keeps the nursery pot above any residual water. Why drainage is so important, you can also read in our blog about drainage with Mediterranean plants; the same principle applies to houseplants.

The material also counts. Terracotta is porous, so the soil dries out faster: ideal for succulents and for those who water too much too quickly. In glazed ceramic or plastic, the soil stays moist longer, and large pots dry out slower than small ones.

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Watering in autumn and winter

From October the light quickly becomes less and most houseplants go into a dormant phase. They hardly grow and evaporate less, so they need much less water. Those who continue to water in winter as in summer, often see yellow leaves and root rot in January. As a rule of thumb, you can halve the frequency in the winter months, but here too let the soil decide.

If a plant is above the heater, the top layer dries out quickly while it can still be wet deeper in the pot; so feel a bit deeper. The same rhythm of less water in the cold months also applies to palms in pots, as you read in our blog about how much water a palm tree needs.

Too much or too little water: this is how you recognize it

In both cases, leaves can hang limp or turn yellow; the difference is in the soil. If the plant hangs limp while the soil is wet, the roots are probably rotting and can no longer absorb water. If it hangs limp in bone-dry soil, then it is simply thirsty.

Signs of too much water

Yellow lower leaves, soft brown spots at the base of the stem, soil that stays wet for days, a musty smell and small black flies (fungus gnats) around the pot. Remove the plant from the pot, cut away soft brown roots and put it in fresh soil; healthy roots are firm and light in color. How to do that, you can read in our guide about repotting.

Signs of too little water

Crispy brown leaf tips, curling or shriveled leaves, soil that pulls away from the pot edge and a noticeably light pot. Then put the pot in water for half an hour, so that the root ball in the middle also gets wet again. Yellow leaves can also have other causes; in our blog about yellow leaves on a Yucca you see how you distinguish them. If you often forget to water, choose from our easy houseplants.