Light is an important food source for our plants. As such, it’s important to understand what level of light our plants need. Here, I’ll be covering the basics of how light applies to our houseplants, as well as what kinds of plants do well in each light condition.
Light can be split up into 4 general categories:
- Direct light
- Bright, indirect light
- Medium light
- Low light
Direct light refers to light that plants get outdoors, or when hot, bright sunlight comes in through a west or south facing window and shines on your plants with no sheer curtain to protect them. Not that this only applies to plants in the direct path of the sunlight, rather than those that receive diffused, ambient light. In a technical sense, east and north facing windows also receive direct light, but they tend to do so during times when the sunlight is less intense.
Succulents and cacti come to mind as plants that obviously do well in direct light, but most established trees will also do well in direct light, though they may need to be acclimated to it more slowly. Note that there are some succulents which do not like too much light. Check out my post on succulents to find out more.
Bright, indirect light is light that has been diffused, but is still bright. This means bright light that is reflected off of walls and other surfaces, or direct light that has been filtered through a sheer curtain. A handy rule (pun very much intended) to follow to gauge whether this light qualifies as “bright” is to put your hand between the nearest/largest light source and your plant, with your hand around 5 centimetres (2 inches) in front of your plant. If the shadow cast by this is clear and defined, then your light is considered bright, indirect light. As a rule of thumb, bright indirect light should be bright but not hot. The room temperature can be high but you should never feel heat directly from rays of light when it comes to bright, indirect light.
Most houseplants like bright indirect light. Pothos, Scindapsis, Philodendron, Monstera, Ficus, etc. perform their best in this light condition.
Medium light is kind of like the light on the floor of a rainforest. Everything is clearly visible, and there is some sun, but it’s dappled and there’s a fair bit of shade. Basically, most tropical plants will perform fine in this light condition, since they’re used to tall trees blocking out the light. However, they’ll truly thrive in bright indirect light if you can give them that. Of course, some plants do better in this light condition than others.
Peace lilies will do better in this light condition, as will most Philodendron.
Low light really pushes plants to the extremes of their survivability. Think rooms with no windows and only artificial light that isn’t intended to help plants grow. Low light is whack as hell, but there are some plants that can (hopefully) survive in low light. Dracaena sanderiana (Lucky Bamboo) comes to mind, so long as you don’t get the variegated kind. Most Sansevieria varieties will also do okay in low light, despite being a succulent. This is why they do well in offices. Peace lilies and Philodendron will also be alright, but expect very slow growth. Non-variegated forms of ivy (Hedera helix) will also survive in low light, which is not surprising given their origin, as will zz plants (Zamioculcas).