Light control is a fact of life for indoor growers, however it can be helpful for outdoor growers too. Those in climates where summers are relatively short, may find it useful to induce early flowering to ensure that there is enough daylight for the flowering cycle to complete before winter really sets in. Growers in gentler climates may find force-flowering provides them with a means to benefit from two harvests rather than just one. Covering plants may also help city-based growers who have to contend with light pollution.
For very small-scale growers there are “sensory tents” designed to provide comfortable, light-
proof environments for autistic children, which can make excellent and convenient homes for marijuana plants. These have the added advantage of being designed for use in houses, so they can actually look quite smart. Growers who have access to a shed can simply move their plants into this. Growers without a shed can make a cold frame with blackout material instead of glass or buy a polytunnel and make use of the frame to support blackout material. Growers with access to an actual greenhouse can use blackout curtains.
There are three key points to making covering plants work successfully in an outdoor environment.
1. Ensure that plants have a chance to grow vegetatively. It can be helpful to start off plants indoors, or at least with some sort of protection to get a head start on the warmer weather. Then you can look to start force-flowering in early summer rather than autumn.
2. Use breathable material to prevent humidity building up as this is an invitation to mould and spider mites (amongst other problems).
3. Once you start your covering routine you absolutely must stick to it every day no matter what, otherwise you will confuse your plants and may lose your yield. Unless you are absolutely sure you can manage this, it would be best to avoid it altogether and perhaps go for a smaller-scale operation indoors where you can use automation systems.