When to Water Your Plants

Follow these guidelines from Weeds in the Jungle to take the guesswork out of houseplant watering

A frequent question I get from houseplant afficionados: "How can I tell when it's time to water my plants?" Beginners often think they can water their plants, say, once a week. Although this method, known as scheduled watering, might work for a while or even indefinitely for easy-going plants like pothos or ZZ plants, it usually leads to problems eventually. One reason is that different plant varieties have distinct preferences for moisture and dryness cycles, so there is no "one size fits all" solution. Additionally, your plants' watering needs will change over time based on various factors such as location, sunlight, dormancy, ambient humidity, and the season.

Watering plants can be more complex than it seems at first glance. The reason behind this is photosynthesis. Even if you enjoy growing plants, you probably haven't thought much about this topic since the fifth grade. So, let's review, shall we? When we water our plants, minerals and other nutrients in the soil dissolve in the water, allowing them to be absorbed by the plant's root system. These nutrients are then used by the plant to fuel photosynthesis. This process involves chlorophyll, a pigment that absorbs red and blue light waves and reflects green ones. That's why plants appear green. There is a connection between light exposure and watering needs. The same plant will require more frequent watering in bright light than in a dim area. This is also why, unless you live near the equator, your plants need less water in winter than in summer. I recently spoke with an experienced indoor gardener who was puzzled by the decline of her beloved snake plant. She had watered it regularly all year, and it thrived, but suddenly in October, it started to die. As the days shortened here in the northeast, her plant was performing less photosynthesis and thus absorbing less water. The excess water remained in the pot, keeping the roots damp. Diagnosis: root rot. Now that we've crossed scheduled watering off the list, let's take a closer look at other ways to determine when to water your plants.

How to determine when its time to water your houseplant

Determining when to water depends on two factors: how dry your plant is and how dry your plant prefers to be. To assess the dryness of your plant, you can use the "finger test." Insert your finger into the soil about an inch deep or up to the first knuckle. If moist dirt clings to your finger when you remove it, your plant is fine. If your finger is dry, it may be time to water. For plants that prefer arid conditions, allow the soil to dry out further; wait to water until the pot feels light in your hand and the soil has a crispy texture. If the soil is so dry that it is pulling away from the container, it is definitely time to water. These guidelines mainly apply to smaller plants (those in 8-inch or smaller containers). For larger plants, it's best to use a water meter because the top few inches may dry out even if there is significant moisture at the root level. The second factor, how dry your plant likes to get, largely depends on the type of plant. When caring for any houseplant, assume that each plant will thrive in conditions that mimic its native environment, so I have grouped them into three categories:

Moisture loving plant

These plants prefer consistently moist soil and do not tolerate drying out well. As expected, this mostly includes species native to tropical rainforests. Ivy and ferns found in colder climates are exceptions to this rule, with key varieties native to the damp British Isles and the rainy Pacific Northwest. Tropical plants that thrive in consistent moisture include philodendrons, peace lilies, pothos, aglaonema, schefflera, spider plants, tropical palms, crotons, calathea, fittonia (nerve plants), alocasia, anthurium, dracaenas, dieffenbachia, African violets, pilea, and begonias.

Medium drought tolerant plants

Plants in this group originate from diverse climates and native regions. Except for peperomia, they are quite resilient as houseplants. These plants can be cared for similarly to those in the first category, but they can also do well and sometimes thrive in drier soil. After conducting the finger test, you can wait a few more days before watering them. This category includes rubber tree plants, ponytail palms, sago palms, ZZ plants, snake plants, peperomia, and desert palms.

Drought tolerant plants

As one would expect, the members of this group are primarily native to arid climates and desert regions. Some, like cacti, are almost aquaphobic, while certain succulents thrive in more humid environments. Regardless, you should wait until the soil is dry, light, and crispy before watering. However, don't delay too much; when succulents can't absorb water from the soil, they start using the water stored in their fleshy leaves. If your succulent's leaves appear shriveled or wrinkled, you may need to water them twice, with a few days in between, to rehydrate them. This category includes nearly all cacti and most succulents, such as echeveria, sedum, sempervivum, haworthia, jade plant, graptopetalum, and crassula.

It's important to acknowledge that there is room for discussion on this topic, and your experience might differ due to various factors. The plants mentioned above are based on my personal experience, and some may disagree with my classifications. For example, some experts suggest allowing philodendrons and other aroids to dry out slightly before watering, or that snake plants should remain moist. Although I disagree, I always encourage readers to closely observe their houseplants, experiment a bit, and find what works best for them. Creating and expanding your home jungle should be about enjoying your time with your plants and learning from them. So, don't worry and have fun watering your plants. Feel free to share your personal experiences in the comments section below. Happy planting! 🪴