Greenhouse Shade Cloth, Blinds, Sheets, Netting, and Shade Washes
Greenhouse shading is needed because you must protect your plants from direct sunlight during the height of summer. The amount of greenhouse shading required will depend on the location of your greenhouse, the local climate, and the lighting requirements of the plants you grow in your greenhouse.
Professionals use shade covers in hot summers to reduce the heat in their greenhouses by blocking a percentage of the heat from the sun. You can reduce the sun’s rays from entering the greenhouse and achieve a substantial temperature drop by using effective greenhouse shading. Additionally, shade cloths will protect those plants that do not like to be in full sun.
Shade covers are varied in cost and effectiveness. You do need to consider the type of plants and how much shade you will need before you buy as they will provide different strengths of shade across a range of options. You don’t want to overdo it and slow down the growth rate too much or prevent the plants from growing! Neither do you want to under estimate the strength of the sun in your location and allow your plants to get overheated or burned on sunny days.
Shading on the outside of the greenhouse is more efficient in reducing the temperature. Shading on the inside doesn’t really reduce the temperature enough but that all depends on the types of plants you have inside and the climate as to how much temperature reduction is required. For a greenhouse with mixed plants you would want a light reduction of around forty to fifty per cent. If you have plants that only grow in shade you would increase that cover, and the opposite would apply if your plants are sun and heat lovers such as cacti.
It is ideal to use shading on the outside of greenhouses around an inch away from the glass, the application will be recommended by the manufacturer.
Slatted wooden blinds look nice and are efficient in that they can be rolled up and down to let in sun on cloudy days and vice versa. Although wooden blinds can be expensive they are hard wearing and as they will be in place for a long time you need a hard wearing material. When doing your assessment of what type of shade material to buy, weigh up the initial financial outlay along with the longevity of the product against the cost.
Although you may find you are constantly rolling the blinds up and down if they are manually operated but you can get automated ones… at a cost of course.
Less expensive alternatives are blinds for inside the greenhouse.
Bamboo blinds look really nice, last a long time, and can be in natural colours that blend into your greenhouse environment nicely, or brighter colours are available in bamboo.
Other types of adjustable shade blinds are made from materials such as plastic.
You can get different grades of shade cloth and as with any other product the price goes up with the higher quality. When looking at shade cloths for this purpose do check on the UV protection given as it will impact on the durability and longevity of the fabric.
Shade cloth can be cut to different lengths and some can even be cut around your greenhouse vents so they still open etc. Ensure you get a cloth that will not tear or fray easily.
Shade netting can be used for greenhouse shade outside or inside greenhouses and also comes in a variety of qualities and therefore prices. Netting is not as adaptable as blinds and some people say that they are not as efficient as blinds or shade washes in reducing temperature, but as improvements to these materials are continually being made I would check that on a yearly basis to see what new products are available.
Gardeners have previously sprayed greenhouse glass with a lime wash and milk mixture in years gone by. However, the result on a cloudy day wasn’t very good as once it had been sprayed on the glass you couldn’t adjust it at all. These days you can get improved and purpose made shade washes and sprays from horticultural suppliers. The improvements made include turning opaque in really bright sunlight but returning to being more transparent during cloudy days.
A greenhouse shade wash may be considered an effective and cheap way to reduce heat in the greenhouse during periods of strong sunlight and at the same time permit light in to achieve plant growth.
Although not as expensive as other options shade washes and sprays may not be considered to be as aesthetically pleasing as other types of shading. It will also involve a bit of work to paint or spray onto the glass and to remove again at the end of summer.
There are also sheets of polythene on the market that clip to the inside of the greenhouse that works in the same way. Whether suitable for the inside or outside of the greenhouse will be recommended by the manufacturer so do read the notes before installing and ensure they will let in sufficient light.