After deciding that light deprivation is necessary for a specific type of greenhouse production, it’s necessary to choose between temporary and full-time light blocking. Taking the plants indoors eliminates the need to drag light blocking tarps back and forth, but complete light blocking has its disadvantages too. Trying to control the light levels too stringently will lead to runaway costs without any extra benefit in harvests. Decide between complete light control or the use of natural light by weighing the benefits and costs of both methods.
Risks of Light Exposure
First, consider how sensitive the particular crop is to any amount of light exposure. If even the smallest amount of exposure will interrupt flowering or throw off leaf development, it’s best to stick with indoor growing only. Permanent structures with solid walls and double enclosed entrances are the best way to control light as strictly as possible. However, most greenhouse crops can handle the occasional brief exposure to light during a deprivation period without getting thrown off track. This means that solid walls are overkill for most crops and light deprivation tarps are more than sufficient.
Cost of Control
Measure the ongoing costs of maintaining a very high level of light control versus using a more relaxed system. The biggest related costs during both installation and operation include:
- Construction of solid walls versus far more affordable tarps and covers
- Extra equipment for manipulating temporary covers or to supply lighting and ventilation in fully enclosed buildings
- Energy expenses to either move covers back and forth or to power costly artificial lighting
- Specialty greenhouse accessories like light blocking vents and doors that cost far more than the standard models.
The more light the plants can handle during deprivation, the easier and less expensive it is to use this technique. Check into the latest research on your chosen species and you’re likely to find there’s a BTL Liners light deprivation cover that will meet your needs.
Artificial Lighting
Once you’ve committed to a full building or other structure that completely blocks out light, you’re also committing to the costs and hassles of artificial lighting. A lamp failure can cost you an entire greenhouse worth of product, while the sun will reliably rise even when there’s a power failure. Automatic retraction systems for light deprivation covers almost always include manual controls, so a power failure won’t leave your greenhouse in the dark. Artificial lighting requires regular maintenance and increases energy costs significantly. Don’t forget to factor in the extra ventilation needed to deal with the heat created by the lights as well.
Broad Spectrum
Aside from cost and heat accumulation, artificial lighting is also naturally limited in the light spectrum it provides. The wide spectrum lighting provided by the sun, even when there are clear materials blocking some of the rays, is simply better at encouraging plant growth than artificial lighting. However, it is now possible to find LED lights that at least claim to provide UV rays to stimulate growth and trigger flowering. However, these lights still don’t tend to quite compete with real light. Consider the extra cost and reduced performance before deciding to completely block out the sun for good.
Changing Demands
Building a structure designed just for light deprivation limits your opportunities to change and adapt later. In contrast, a clear glazed greenhouse covered with a temporary light blocking tarp is changed in mere hours to adapt to any other use. When markets change or you discover a new method for triggering optimal plant growth, light deprivation covers allow you to adapt your existing structures as quickly as possible. It’s also much easier and faster to add these covers to existing greenhouses than to build new structures just for light dep.
Not only are light deprivation covers a smaller investment than new construction, but they’re also more flexible and easier to repurpose in the future. Don’t be discouraged by stories of low quality or unreliable light deprivation materials from other suppliers. Stick with BTL Liners for light dep covers you can rely on for years to come.
