Let more light in under cover
Give your greenhouse a Christmas sparkle with a good soapy scrub
Growing plants in a greenhouse or polytunnel over the winter comes with a few challenges, usually brought on by the weather and lack of natural light. If it’s very cold, we can always crank up the heat for a few days if needed, but there’s not a lot we can do when it comes to the short days of winter and cloudy weather when the sun doesn’t make an appearance.
Poor light conditions, however, can stress plants so we need to maximise the light getting to them to keep them healthy and ticking over. Dirty greenhouse glass will reduce light transmission. Even if you wash it down a couple of times a year, you’ll be surprised how grimy the glass can be at this time of the year.
I always try to give the greenhouse a good wash down around now and, if done regularly, it doesn’t take too long. I simply use some warm water with a little washing-up liquid in, which seems to remove the dirt from the glass and the frames very easily. I use a car washing brush to make light work of the job and so that I don’t need to get out the stepladder to reach the top of the roof. A good scrub then a rinse with clear water will really clean the glass and remove green algae that has built up on the shady side. The polytunnel gets the same treatment and it makes a big difference to light transmission.
It’s also a good idea to clean out gutters for a final time now that all the leaves are off the trees, to prevent the rotting leaves washing into the water butts and contaminating the water. With the glass clean and sparkling, not only does the greenhouse look better, but the plants will also benefit! Have a happy Christmas and enjoy pottering under cover!