Struggling to figure out the perfect lighting schedule for your indoor plants? Thinking more light equals more growth? It’s a tempting thought, but often wrong.
Generally, no, you should not leave grow lights on 24 hours a day. Plants need a period of darkness to properly develop. Think of it like sleep for humans – it’s essential.
Let’s clarify the common confusion about grow light schedules.
How Many Hours a Day Should You Use Grow Lights?
Confused about how long to run your grow lights? Worried you’re not giving your plants enough, or maybe too much? It depends on the plant.
Most plants need between 12-16 hours of grow light per day. Seedlings might need up to 18 hours. Always check the specific needs of your plants.
It’s not a one-size-fits-all answer. Just like different people have different sleep needs, plants have different light requirements. Some examples:
| Plant Type | Light Needs (Hours) | Notes |
|---|---|---|
| Leafy Greens | 14-16 | Consistent light for steady growth |
| Fruiting Vegetables | 12-16 | More during flowering/fruiting stages |
| Herbs | 12-14 | Varies; some prefer less, some more |
| Seedlings | 16-18 | Promotes strong initial development |
It is important to find out the exact light requirements for what you’re growing.
Do Plants Benefit from 24 Hours of Light?
Thinking constant light will supercharge your plants’ growth? Tempted to leave those grow lights on all day and night? It can actually have the opposite effect.
No, most plants do not benefit from 24 hours of light. They need a dark period for essential metabolic processes. Continuous light can stress plants and hinder growth.
Plants don’t just use light; they also need darkness. It’s like a work-rest cycle.
| Process | What Happens | Light or Dark? |
|---|---|---|
| Photosynthesis | Plants create energy from light | Light |
| Respiration | Plants use energy and process nutrients | Dark |
| Transpiration | Plants release water vapor | Both |
| Growth Regulation | Hormones control growth and development | Both |
I recall a time, like when, a customer once tried leaving their grow lights on non-stop. They thought they’d get huge, fast growth. Instead, the plants became weak and pale. How long you should turn on the plant’s grow lights actually depends on the demand of the crop. For industrial crops like cannabis, different periods have different requirements. During the vegetative period, it is common to use a 18/6 hour light/dark cycle, cutting to 12/12 during the flowering period. Giving plants darkness is a simple and important way to keep plants healthy.
Conclusion
Giving your plants a break from light is just as important as giving them light. Mimic nature, provide a dark period, and your plants will thank you.
