Total darkness, without a single leak
Blackout screen systems for chrysanthemum, kalanchoe, poinsettia and every other day-length sensitive crop. Tight on the roof, the side walls, the gables and every seam in between. Designed, built and installed by ALWECO.
The cloth blocks 99.9%. The installation decides the rest.
Modern blackout cloths block up to 99.9% of the light. That figure is about the cloth. Whether your crop really gets a dark night depends on everything around it: the closing edge, the overlaps between screen sections, the connections at gutters, trusses and columns, and the side walls and gables.
A short-day crop reacts to small amounts of stray light. One open seam can be enough to delay flowering or make a batch uneven. That is why a blackout system has to be designed as a whole, and installed with attention to every detail.
ALWECO has been designing and installing greenhouse screen systems for more than 35 years. We develop many of our components ourselves, so we can make the seal fit your greenhouse instead of the other way around.
For every day-length sensitive crop
Blackout lets you give a crop the night it needs, whatever the season. Each crop asks for its own approach to darkness, climate and cloth.
Chrysanthemum
An autumn flower that blooms when the nights are long. With a blackout screen you create those long nights every day of the year and keep year-round production on schedule.
Kalanchoe and poinsettia
Pot plants that need short days to flower and colour. Reliable blackout keeps batches uniform and ready for the planned sales date.
Cannabis
Precise photoperiod control for flowering, with no stray light. More on cannabisblackout.com
Lit crops
Growing under lamps at night? A closed blackout screen keeps the light inside, for your neighbours and for the rules on light emission.
Where light gets in, and how we stop it
A blackout system is only as good as its weakest seam. We look at the whole greenhouse and close every route light can take.
Closing edge and overlaps
Our own Ultra Lock screen profiles and Ultra Delay slip blocks make sure the screen closes tightly, every time, and the overlaps between screen sections stay closed.
Gutters, trusses and columns
Every greenhouse construction has its own obstacles. With the Ultra Tight closing profile we seal along gutters and trusses, in glass and poly greenhouses, new or existing.
Side walls and gables
Vertical blackout screens close the walls, so no light enters from the side. Driven by our own tubular motors and built to run smoothly day after day.
Partition walls
Want sections with different day lengths? Blackout partition walls divide the greenhouse, so each crop or batch gets its own dark period.
Choosing the right blackout cloth
Blackout cloths differ in layers, colours and materials. The right choice depends on your crop, your climate and whether you grow under lamps.
Aluminium or white on top
An aluminium top layer reflects sunlight and keeps heat inside at night, for extra energy saving. A white top layer is lighter and helps keep the greenhouse cool.
White or black underneath
A white underside reflects lamp light back to the crop. A black underside absorbs light and helps keep it inside the greenhouse.
Moisture and fire safety
Knitted blackout cloths let moisture pass through the closed screen. Flame retardant versions add safety in greenhouses with lamps.
Darkness without a damp crop
A blackout screen is closed for many hours a day. Under a heavily insulating screen, moisture and heat build up, and that is where problems such as condensation and fungal disease start.
We design the installation with the climate in mind: a cloth that lets moisture through, room for air treatment that brings drier air from above the screen, and the option to combine blackout with an energy or shade screen, so you can always choose the right layer for the moment.
We get it done
35+ years
Founded in the Westland, the heart of Dutch greenhouse horticulture.
Worldwide
Design, installation and renovation for any greenhouse construction, anywhere in the world.
Short lines
A small team of specialists, with a screen expert always on the line.
A deal is a deal
Clear quotations, deadlines met and service and maintenance after delivery.
Frequently asked questions
How dark does a greenhouse get with a blackout screen?
Modern blackout cloths block up to 99.9% of the light. Whether the greenhouse itself becomes truly dark depends on the installation: the closing edge, the overlaps, the connections at gutters and trusses, and the side walls and gables. That is where we focus.
Which crops need a blackout screen?
Short-day crops such as chrysanthemum, kalanchoe, poinsettia and cannabis. They need long, uninterrupted nights to flower, and a blackout screen lets you create those nights at any time of year.
Can blackout and energy saving be combined in one installation?
Yes. A blackout cloth with an aluminium top layer also saves heating energy when it is closed at night, and a blackout screen can be combined with a separate energy or shade screen in one installation.
Can an existing greenhouse be fitted with blackout screens?
In most cases, yes. We design blackout installations for new builds as well as for existing greenhouses, including side walls, gables and partition walls.
Does ALWECO install outside the Netherlands?
Yes. We design and install screen systems for greenhouses all over the world and remain available for service and maintenance after installation.
Planning a blackout system for your greenhouse?
See all our blackout solutions and reference projects on the ALWECO website, or ask one of our specialists for advice and a clear quotation.
Go to alweco.nl