Turning up the light for your indoor plants
Sweet peas in May
Our polytunnels are in constant use, as soon as a bed is finished or productivity drops, it’s cleared and replanted with the next crop. We’re currently planting out hardy annuals, ranunculus and anemones to grow on through the winter.
As the days shorten and natural light levels fade, it’s really important to get as much light as possible into the tunnels. The health of a plant is determined by its ability to photosynthesise – to turn sunlight into sugars which is used for all the metabolic processes. Light energy is essential to make this happen. Sunlight is made from a spectrum of colours. When you see a rainbow, what you actually see are raindrops splitting sunlight into these different colours. Photosynthesis uses predominantly red and blue parts of this spectrum, and not green light
When we have a polytunnel which is covered with algae we create a green filter which allows more of the green part of the spectrum to go through and reduces the red and blue light available to plants and therefore dramatically reduces the ability of the plants to efficiently photosynthesise.
This week Ray led the charge in cleaning the tunnels. He made a flossing tool (nothing to do with dancing!) from a long length of rope covered in foam pipe insulation and felt, secured with duct tape. We mixed up a cleaning solution to remove the algae that has built up over the summer. We’ve bought a proprietary algae removal solution in the past but when we looked at the ingredients it was basically vinegar, so now make our own using
Half cup vinegar
Gallon water
Egg cup of washing up liquid
This was brushed onto the cleaner and then we gently pulled the rope on at each side to rub off the algae. A quick rinse with the hose and it was like someone had turned on a light in the polytunnel. Our days are short in Scotland during the winter, only 6 hours of daylight in December and January and cloud cover reduces its quality. The more light we can get in for our plants, the healthier they will be and the more flowers we’ll have in the Spring. Definitely time well spent!
Ray’s polytunnel flosser (patent pending|)