What does watering my plants do?
Water provides structural support, cools your plant down, and moves minerals to all the right places.
Think of plant cells as water balloons. When they are filled with water, they become stiff, and your plant stands upright. When there is a lack of water, the cells deflate, and the plant looks wilted—a clear sign your plant needs more water if paired with dry potting mix. Plants also produce cellulose that help them keep their shape, but water pressure (water flowing through the plant) helps plants gain and retain their shape better than cellulose alone.
When you water your plant, an invisible process called transpiration occurs. The sun evaporates water from the leaves through their stomatal pores, causing water loss in the leaf. That’s great, because available water will go where it’s needed most. Ideally, the water is pulled up from the roots, but if the roots are dry, water is taken from the leaves themselves.
How often should I water my plants?
Much like different plants need varying amounts of light, different plants need varying amounts of water. To get a sense of how much water your plants might need, think of your houseplants’ natural environments: are they hot and dry, or rainy and tropical?
Desert natives like succulents like to stay dry and will benefit from less frequent waterings. Succulents come from hot arid environments, prefer to be watered less frequently than plants from tropical habitats, and have a physical characteristic that relates to their moisture-storing capacity. For example fleshy leaves, thick stems, or rhizomes. Some have shallow root systems, indicative of growing in places where rain is infrequent and rarely enough to soak deep into the ground. When you water succulent plants make sure their potting mix dries out completely afterward and wait a few weeks before watering again.
Unlike succulent plants, tropical plants like the Monstera deliciosa or Bird's Nest Fern are used to frequent rain showers in their natural environments. They did not adapt succulent characteristics to store water and tolerate drought. These leafy plants will thrive with more frequent waterings, about once a week or so.
How much should I water my plants?
In addition to the variety of the plant, the size will also determine how much water it needs. Potting soil is like a sponge. In smaller pots with less soil, the soil will dry out faster than in larger pots with lots of soil. If you have two of the same plant and one is larger than the other, one will need water more often than the other.
How to Water
Step 1: Check your potting soil to determine if it is dry. Most plants benefit from drying out completely between waterings; some moisture-loving plants like ferns can be watered again when the soil is mostly dry.
Step 2: If the soil is dry, fill a watering can or vessel with room temperature water. Some plants can be sensitive to tap water; try leaving your water out overnight before watering.
Step 3: Water the potting mix evenly around the plant. You want to saturate the soil but not create mud. Avoid splashing water onto your plant's foliage, which could cause fungal or bacterial spots. (Unless, of course, your plant is an epiphyte without soil.)
Step 4: Water up to one-fourth or one-third of the volume of your planter. For planters without a drainage hole, be especially mindful of how much water you're using. For planters with a drainage hole, water until you see excess water drain out of the bottom of the planter. You can let the water sit in the saucer or cache pot for 15-30 minutes, allowing the plant's roots to soak more up, then discard it.
Should I set a watering schedule?
We’re inclined to ‘stay hydrated’ but plants can drown if they are flooded with too much water. That’s what we call overwatering. If potting soil is left too wet for too long, your plant can start drooping leaves or get root rot. On the other hand, if your plant’s soil is consistently too dry, you’re likely underwatering.
So what should you do? Be flexible in your plant care habits. Don't stick to strict schedule—watering on exactly the same day every week may do more harm than good. Use that day to check in on your plants instead, watering only those that need it.
Pro tip: It is easier to add water to potting soil than to subtract it. If you're worried you might overwater your plants, err on the side of underwatering instead.
Do the seasons impact how much water my plants need?
The seasonal changes outside impact your plants' growth inside. During the summer growing season, the sun is stronger and out longer. Most houseplants, including succulents, will benefit from more frequent waterings. Succulents—that happily went a month without water while semi-dormant in the winter thanks to shorter days with less light—might need to be watered every week come summer. While tropical plants might need water twice a week, compared to every 1–2 weeks in winter.
What else should I know about watering houseplants?
There are some golden rules to keep in mind for watering your plants:
– Most houseplants prefer warm or tepid water over cold water, which can shock your plant. Warm water absorbs into soil best.
– Some houseplants are sensitive to tap water. Let water sit overnight for chlorine to dissipate before using.
– Plants in large planters dry out more slowly than plants in small planters because of the volume of potting soil.
– Try not to splash water onto your plant’s leaves when watering. Fun fact: Most tropical plants have waxy leaves because the rainfall in their natural environment, the rainforest, can be excessive. Waxy leaves helps water slide off and avoids risk of fungal infections.
– Expect to water plants more often in brighter light and less often in lower light, unless they are a drought-tolerant succulent.
– If you're afraid to overwater, look out for visible signs of thirst first, like wrinkling leaves for succulent plants or drooping stems for tropical plants, paired with dry potting soil.
Words By The Sill
Empowering all people to be plant people—a collection of articles from The Sill’s team of plant experts across a variety of plant care topics to inspire confidence in the next generation of plant parents. Welcome to Plant Parenthood™.