Chrysanthemum blackout curtains?

Hi all

A friend of mine got a job in a greenhouse and I got a chance to visit during the end of the construction before they start operating.

During the tour, I asked if he could shut the blackout screens so that I could see how dark it got in there. With the curtains drawn, it was quite dark, but not pitch black. It was dark enough that I couldn't see obstacles on the floor, but there were little pin holes visible through the curtains, and a couple spots along the edges that leaked very sightly. It was mid afternoon on a very sunny day.

When I voiced my concerns that I thought it needed to be darker he said the dutch manufacturer had insisted that it was "dark enough" and said this is what they use for chrysanthemums in Holland.

I've done much googling and cannot seem to find any info on the relative difference in darkness levels required by cannabis vs chrysanthemums, but I suspect my friend is in trouble here. i'm an indoor guy and have always achieved total darkness so I have no experience growing with minor light leaks.

Any insight into this would be very helpful.

Thanks

Have you ever done an outdoor grow?

If so, how dark was it really at night near your plants?
It's not pitchblack as you might can find into the deepest caves on earth or sealed indoor growrooms, there is moonlight, starlight, other light sources...

Compare that to the level of light into the greenhouse with the curtains closed.

Cheers.

It is dark enough, blackout for photochrome reduction means you only need to not be able to read a newspaper about a metre away when the curtains are drawn. If you get hermies from this it means you need to select better genetics for greenhouse production.

Many 'greenhouses' for cannabis are having problems for total darkness only by their 'growers' standards. You should let you friend know that blackout in the morning is also better as you're not stopping transpiration as you would in the afternoon and humidity levels are better controlled, hopefully he has svensson ludvig screens in as they have the best transmission of moisture through the fabric.

its not a problem I have used greenhouse ground cover as blackout fabric because I couldn’t get my order in time for proper fabric..

Limeygreen said:

You should let you friend know that blackout in the morning is also better as you're not stopping transpiration as you would in the afternoon and humidity levels are better controlled

Click to expand...

Very useful tip

Little Leaks from corners and stuff doesn't cause hermies with light depp. It's Because the blackout is only a couple hours long and the rest of the dark period is just night time.
Inside a light Leaks can be 12 hours long.

Thanks for all the replies

Thanks for all the replies

always appreciated