From watering, fertilizing, and repotting to fighting off diseases and mites, there’s a lot to monitor when it comes to raising happy, healthy indoor plants. But most plant issues stem from one thing (or lack thereof): light. Light enables plants to photosynthesize, which creates the sugars they need to grow and thrive. It’s no exaggeration to say that light is a plant’s lifeblood, no matter what their preferred environmental conditions — they quite literally can’t survive without it.
If you’re concerned about the light conditions in your home or apartment, you’ve come to the right place. Below, read up on all things indoor plant lighting, from photosynthesis 101 to plant grow light bulbs and everything in between.
The Importance of Indoor Plant Lighting
To reiterate the above statement, plants absolutely need natural light sources to grow. While some plants can tolerate extremely low-light conditions (we’re looking at you, ZZ plant), any claims that a plant can thrive without any light at all are simply false. While some are able to adapt or survive for a short amount of time, they will not thrive, especially in the long run.
In the words of Darryl Cheng, engineer, author of House Plant Journal, and inventor of a light meter app, “understanding light is the best way to truly understand what your plant is going through,” he shared with Bloomscape. “The correct lighting is what plants require to function. The people you think have a ‘green thumb’ are simply the people with the most windows.”
As National Geographic explains, “photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar.” Basically, plants capture energy from the sun to produce oxygen and create glucose. Plants use glucose to grow and reproduce, and excess glucose is stored in the leaves, stems, and roots (which are then eaten by higher organisms like animals). In other words, more light equals more photosynthesis, which equals more growth and vitality.
Your Guide to Indoor Plant Lighting
Of course, various types of plants prefer different lighting conditions based on their natural habitat. Succulents and cacti, for example, are native to deserts and extremely dry climates and therefore love hours of sunlight and minimal watering. Tropical plants like ferns, birds of paradise, and palms, on the other hand, prefer bright, indirect light and more frequent waterings to mimic a rainforest environment. Here’s how to position different plants for each type of lighting condition.
Types of Sunlight
Bright, Direct Light
Drought tolerant plants like cacti, herbs, and succulents fall into this category and love a bright, south or south-west -facing window or window sill so they can soak up as many hours of direct sun as possible.
Bright, Indirect Light
Plants like Heartleaf Philodendron, Dracaena, and Ficus Altissima love bright, indirect light. They can handle a couple of hours of direct morning light from an east-facing window, but they can burn in direct afternoon sun. Another option is to place a sheer curtain on your south or west windows to protect plants from harsh direct sun.
Hardy, medium to low-light plants like the ZZ plant, pothos, and snake plants can adapt to basically any conditions — including a poorly-lit apartment or office with only fluorescent lighting. While these plants usually prefer bright indirect light, they will tolerate less than ideal conditions. When keeping a plant in lower light situations, you will need to adjust the amount of water you give your plant because they will be photosynthesizing less in these conditions.
Window Direction Matters
North-facing windows give off lots of medium indirect light that is suitable for low light plants. No direct sunlight will come in this direction.
South-facing windows receive the most hours of direct sun per day. They receive direct light almost all day except early morning and late afternoon. South-facing windows are a great option for plants like cacti, succulents, and your indoor herbs and vegetables.
East-facing windows will receive a couple of hours of direct morning sun, and bright indirect light the rest of the day. East-facing windows are a great option for most of your tropical plants that love bright indirect light.
West-facing windows will receive direct afternoon/evening sun and bright indirect light the rest of the day. West-facing windows are a great option for plants that like some direct light, like succulents or succulent-like plants.
How to Tell if Your Plant Is Getting The Right Amount of Light
Fortunately, your plant will clearly tell you if it’s getting too much or too little sunlight. Those with not enough light will grow slowly, if at all, and sport yellow, droopy, and wilted leaves. On the other hand, plants exposed to too much heat and sunlight will have brown, almost burnt leaves and singed tips.
When to Consider a Grow Light
If you’re concerned that your plants aren’t getting enough light in your living space (particularly if you live in an area with harsh winters), an LED Grow Light can get them through. These LED light bulbs produce a specific photosynthetic light that mimics the light of the sun and allows plants to produce their necessary sugars. LED lights are perfect for herbs, succulents, and other light-loving indoor plants that may struggle with low-light seasons. Best of all, they’re relatively affordable, long-lasting, and easy to use. For our complete guide on Grow Lights, read How Grow Lights Take Your Indoor Herb Garden to the Next Level.