We talk a lot about grow lights here at Fig & Spruce. The number one question that new gardeners in regards to using grow lights is – how long should grow lights be left on?
Don’t worry! We’re here to answer this question and more! Interested in our top pick for grow lights in a small space? We recommend grow light like this one because it has adjustable settings, and a timer that makes it lower maintenance than some other models.
How Long Should Grow Lights Be Left On?
A General Rule: 12 – 16 hours
The amount of time grow lights should be left on can vary from plant to plant. But a good rule of thumb for most indoor plants that require fair amounts of light is anywhere from 12-16 hours.
It is important that you don’t leave grow lights on 24 hours a day. Just like humans, plants need some time to rest! While under grow lights they’re busy going through photosynthesis, and cant do that 24/7. You want to make sure that your plants get at least 6 hours of darkness to avoid hindering their growth.
Supplementing Natural Light
Lets say you have your plants in a room that only gets sunlight for a few hours each day. Or, you’re planting a patio garden that is shaded most of the day and your plants only get indirect sunlight.
These are situations where you may consider supplementing the natural light with a grow light, to help make up for some of the time that your plants are in the shade. This could mean you only need 3 hours of grow light time per day to supplement the natural light you’re plants get.
Selecting the Best Grow Light
As we covered briefly earlier, you’ll want to ensure you select the right grow light for your plants and space. For small spaces, we recommend using a small adjustable grow light that you can clip onto another fixture.
Another key feature you’ll want in a grow light is for it to have programmable settings. This will allow you to set your desired setting, say 12 hours of light and then 12 hours of dark. Your light should automatically switch on and off without you adjusting it day to day.
Hydroponic Grow Lights
For those exploring hydroponic grow systems, you’re in luck! Often small at home hydroponic grow systems already come with built in grow lights. The more advanced systems will have pre-programmed settings for different types of plants, and allow you to adjust each setting as needed.
For more info on selecting a hydroponic system, check out our best hydroponic systems for beginners. Or, check out how does a hydroponic system work for more background information.