sunlight – How to Care for Houseplants

A Few Notes About Light for Houseplants

Plants require light to produce food. Outdoors that is not a problem but for houseplants light can be quite limited.

I recently did a search for “houseplant care” and was surprised to see that the top, non-paid search result defined high light for an indoor plant as any light for more than six hours a day. Here is a quote from that result – “Houseplants typically require high light (six or more hours a day), medium light (four to six hours a day), or low light (less than three hours a day).” This is simply bad, and incorrect, information.

That gardener’s path is incorrect and I hope that if you find that website you will go on to other results as the person running that site is just making stuff up. He may have a few houseplants, or perhaps not, but…

First and most important, no houseplant should receive light for less than eight hours a day at the minimum. That is if you want your houseplant to be growing, not dying. Your houseplant requires light to produce food to keep itself alive.

Light is measured in intensity and foot candles and lumens are used to describe the light intensity. I have a light meter that measures light intensity but you may not need this type of tool for your plants at home. The meter is much the same as one that a photographer might use to make sure photographs look their best. You may not use a light meter but it is a good idea to know about light intensity, how it is measured, and how important it is for a healthy, growing houseplant.

Low light, medium light and high light fall between 25 foot candles to 250+ foot candles. Low light is at the lower end of that measurement and high light at the upper end. As an example, I have a sliding glass door that faces to the north. The light meter gives me a reading of about 185 foot candles just inside the door on an overcast day. A perfect spot for most houseplants (except my pets would eat them), bright light no direct sun.

When I step back from the glass door about 5 feet, I get a reading of about 40 foot candles, on the same overcast day. When I step outside the glass door onto the patio, same overcast day, I get a reading of 360 foot candles. That is a big difference. Just a note, this picture is not where I measured the light levels. Although, it does show houseplants in nice lighting.

While you may not be able to measure the light intensity in your home, suffice it to say that providing medium to bright indirect light is going to be best for just about any common houseplant. Pick the brightest spot with indirect light. For the most part, your houseplant will not need direct sunlight. Indirect sunlight will be fine.

Duration is the length of time your plant is exposed to light each day. This is called the day length or photoperiod. The amount or length of time that houseplants require light is 8 to 16 hours a day. Medium to high light is okay for just about any houseplant for a minimum of 8 hours. That is if you want to keep them growing and looking good.

Light quality is the next consideration. Sunlight is composed of different wave lengths or colors. It has all of the colors, or light wave lengths, that plants require to survive, thrive, and grow. These colors are the light spectrum. You can see many of those colors in a rainbow. Some are more essential to plant growth (blue and red) and may not be present with some types of artificial light. So indirect sunlight is easiest and best for assuring your plants do well. And it doesn’t cost you anything. Use either lights made for growing plants or cool white fluorescent lights if “real” light is not available.

There are many things that affect the natural light indoors, like the size of your windows, the time of year, cloudy, overcast days and even lots of trees growing outside of your windows. Keep these things in mind as you find a well-lit place for growing your indoor houseplants! If you have any houseplant care questions, you can send them my way. Thanks for visiting www.PlantAndFlowerInfo.com