How long to run my lights for?

Figuring out how long to power your lights for can be quite confusing to those new to indoor gardening, so we have written a short blog for those that need some pointers.

There are many different opinions and theories about a plants photoperiod, rather than go too deep into it, we will just talk about lighting appropriate to indoor growing.

How many hours light should I give my plant in the vegetative phase?

18 Hours on – 6 Hours off

The focus in this phase is vegetation ‘Growth’ plants under this photoperiod would remain in a constant state of vegetation, so this phase is ideal for those who wish to keep mother plants as stock to take cuttings from, or just grow a really big plant.

Most growers, whether from seed or cutting would use this photoperiod to grow their plants for a specified amount of time, when we change the photoperiod the hormonal response of the plant changes, which triggers flowering. 

“The spectrum the light needs to be for this photoperiod is ideally: 6K (Kelvin) Which is a white/blue light.”


How many hours of light do my flowering plants need?

12 Hours on – 12 Hours Off

The Grow Room LED lights on

This photoperiod is designed to stimulate a hormonal change within the plant, after approx. 7-11 days of flowering being initiated, the plant would have set out its final form/growth pattern, the plant will now flower aggressively until maturity.

“The spectrum the light needs to be for this photoperiod is ideally: 2-3K (Kelvin) Which is a yellow/orange light.”

With new technologies emerging almost every year, traditional lighting methods can actually be replaced with lighting systems that are considered full spectrum (start to finish) these type of lighting systems use much less power without compromising yield.