PLNTSdoctor banner

How to water houseplants?

Watering your houseplants sounds easy. Yet it is something that many people struggle with, especially when it comes to doing it the right way. There are so many factors that make it difficult to know exactly when and how often to water, let alone how much each plant needs. We would therefore like to help you get a better idea of how to water your plants correctly.

How much and when should I water my houseplant?

Every plant has different watering needs. If you're not sure how much to water your plant, think about where it comes from. Many popular houseplants come from tropical regions where it rains regularly. These species often have large leaves and lush foliage, which require a lot of moisture to look good. On the other hand, desert plants like cacti and succulents need less water. They often do better if you let the soil dry out between waterings.

Once you have determined your plant's watering requirements, it's time to check how moist the soil is. This way, you also know if it really is time to water your plant already. Houseplants can be categorised based on three different watering needs to make things easier for you:

  1. Houseplants with low watering needs - These plants need infrequent watering and are very tolerant of drought. Typically, the soil should be completely dry before watering again. Snake plants, ZZ plants, cactuses and succulents fall into this category. When it’s the right time to water? It’s time to water when you haven’t watered this plant for at least a week. The soil looks pale in colour and feels dry from the top and bottom.

  2. Houseplants with average watering needs - These plants need a balance. Their soil should be kept moist but not soggy. A spider plant, a peace lily, and a philodendron fall into this category When it’s the right time to water? - Water these plants when the soil ball has slightly dried out. The leaves might start to droop slightly, or you notice the pot feels light when lifted.

  3. Houseplants with high watering needs - These plants require consistently moist soil and may need watering several times a week. Prayer plants, Peace lily, Fittonia and different ferns fall under this category. When it’s the right time to water? - Check these plants daily or every other day. If the soil's surface feels dry to the touch, it's time to water. Also, these plants might show early signs of dehydration, such as wilted or brown leaf tips. It is best to give them a good 'tropical rain' in one go so that the entire pot is thoroughly moist, after which it will slowly dry out again.

watering monstera

What factors influence my plant's water requirements?

As we mentioned before, many different things can affect how much water your houseplants need. It's not only about what kind of plant it is. Here are the other factors you should consider:

  1. Size of the plant - A large houseplant or houseplant with larger leaves will use much more water than a similar small houseplant.
  2. Size of the pot/soil ball - The larger the pot, the more potting soil and the more water it can absorb and distribute. In contrast, small pots may require more frequent watering because they dry out more quickly.
  3. Soil/substrate type - Peat-based soils can hold water better, providing a consistent supply to the roots. Sandy soil drains more quickly and might require more frequent watering. There are special kinds of substrates that can absorb water and release it slowly over time. These will ensure that a plant or actually the roots will not get too much water in one go. Check our page about the differences between potting soil and substrates to be well-informed about this!
  4. Light exposure - In bright light, plants photosynthesise more, which leads to greater water use. Also, bright light can heat the soil, causing it to dry out faster. Therefore, plants in bright light often need more frequent watering than those in low-light conditions.
  5. Seasons/Weather - Many houseplants grow less in autumn and winter. If you notice that your plants grow less than usual, they will also use less water.
  6. Temperature and humidity - Heating or air-conditioning causes the air humidity to drop, which in turn causes the houseplant to use more water. As temperatures rise and humidity drops, water evaporates more quickly from the soil, and plants utilise more water to cool themselves.

Different watering techniques

Now that you know when and how to water your plants, you might wonder how to do it. There are two basic methods - top and bottom watering. We will explain both methods more below:

Top watering

The soil feels dry, so what now? Begin by filling your watering can with room-temperature water. Water temperature is important as too hot or cold water can shock your houseplant roots. You might now think about just lightly sprinkling some water on top. After all, you don't want to drown your plant, right? Well, here's the thing: a light sprinkle might not be enough. Your plant's roots, which need moisture the most, aren't just at the soil surface.

So, what's the right way to water? It is important to completely drench the soil. Pour in enough water until it begins to run out of the drainage holes at the bottom of the pot. If you put a saucer under the pot, any excess water will collect there, and your plant can absorb a bit more if it needs to.

Expert tip! Make sure to empty the saucer after 10 minutes. In addition, make sure that too much excess water does not remain at the bottom of the outer pot. If it does, pour it out. Extended contact with excess water can cause the roots to rot, and we certainly don't want that!

Bottom watering

Bottom watering is a method where you place the pot in a container of water and let the plant absorb moisture through the drainage hole in the bottom. This is a great watering method since roots absorb as much water as they need. When they have had enough, they stop absorbing.

Just place your houseplant with an inner pot (with holes in the bottom) on a saucer or bowl with water and keep it for about 30 minutes. Your plant will then suck up the required amount of water itself. So pour water into the saucer/bowl as many times as necessary until the plant no longer sucks it up. This works especially well with small to medium houseplants.

Larger plants are easier to put in a bucket or other large container with water. Make sure the water reaches about halfway up the plant's pot. After a while (wait for an hour or more), the plant will have absorbed all this water. Keep an eye on the water in the bucket or container, it should become less and less. When this is no longer the case for 20 minutes, this is the sign that the plant has absorbed enough water.

Expert tip! Remember not to leave your plant in a water bucket for too long. If it's in the water for too much time, the roots may not get enough air, and they could get hurt. But don't worry, if you've accidentally left it soaking for too long, just take it out. Let the pot hang out in the open air to help it dry out a bit quicker. That way, your plant will be back to feeling its best in no time.

Check if the soil has dried out with a water meter

A simple way to monitor your plants' water levels is by using a water meter. It's a really useful tool! There are water meters that consist of a plastic tube with a sort of polystyrene float and a meter stick inside. As soon as the water meter comes into contact with water or damp soil, the polystyrene floats, and the meter rises. There are also water meters that change colour so you can see if the plant still has enough water or if it needs a little water again. Usually, the colour of the display changes from blue to red when watering is required. But our Tessa water meter changes to a white colour when she’d like a sip!

Is tap water safe for houseplants?

You think you have covered everything, and then doubt suddenly sets in. Can I give my plants ordinary tap water? Yes, you can, but... you need to make tap water safe for plants. Just prepare your watering can at least 24 hours earlier, so the chlorine and fluoride can evaporate from the water and the water is also at room temperature before your plants get it.

Tap water contains very small amounts of chlorine and fluoride, and some plants are more sensitive to this than others. If your plant has brown spots/edges, it could be that it is caused by watering too often with chlorine and fluoride.

Expert tip! If possible, give your plants rainwater. Rainwater contains more oxygen than tap water, so the plant can absorb nutrients even better. Do you have a rain barrel? Then drain the water in an empty bottle and let it come to room temperature for at least 24 hours. Do you have regular rain showers in your country? Then you could also put a bucket outside to catch the rainwater.

Some research suggests that sparkling water could be potentially beneficial for houseplants. It is thought that the dissolved carbon dioxide in sparkling water might help in nutrient absorption by the roots. This may lead to better growth and development of the root system. As a result, your plant will therefore grow faster and form more beautiful, greener and larger leaves. Only the best is good enough for your plant children, right?

watering can

6 tips you need to know about watering

  1. The biggest reason for plants to die is too much water and, therefore, root rot. It is for this reason that it is often better to give too little water than too much. Root rot is difficult to fix, and dehydration only really occurs when plants are structured without water for long periods.
  2. The best and easiest way to check whether your plant needs water is to simply stick a finger or a wooden stick, at least 3 centimetres (watch out for the roots), into the potting soil. If the soil sticks to your finger or the wooden stick, it is still moist enough. If your finger/stick comes out clean, you know it's time (or almost time) to water your plant.
  3. Another way to check your plants is by lifting the pot. A plant with dry soil does not weigh that much. After weighing it a few times, you will get a feeling for it, and you will also be able to feel if the plant needs water by the weight of the pot.
  4. The best time to water your plants is in the morning. If the leaves get wet, then they have all day to dry out. It is much harder for plant diseases to gain a foothold when the leaves are dry. If you cannot water in the morning, the best alternative is in the evening.
  5. When you water your plant with a watering can from above, make sure that you water well around the plant. Do not water just one spot. Preferably not too close to the plant/the stem itself. There are many plants that do not like it when they get wet or stay wet for a long time.
  6. Last but not least, ALWAYS put your plant in a pot with a drainage hole. This allows excess water to drain away. Many beautiful pots do not have a drainage hole. So put your plant in an inner pot with holes that fit into that lovely decorative pot. This way, the plant is still in a good pot.