As we enjoy the lengthening sunlight of late winter, it’s hard to imagine being interested in shade. But if you’re planning to build a greenhouse, creating shade for the hottest days of summer should be on your list of considerations. While it’s possible to grow plants in hot greenhouse environments, high temperatures will limit the selection of plants your greenhouse can grow successfully. Even heat-lovers, like succulents and sweet peppers, require more frequent watering in hot, drying conditions. Many other plants– geraniums, tomatoes, and salad greens will sulk if temperatures rise too high. Carefully consider the plants you want to grow before you build your new greenhouse.
You can site your greenhouse where it will be shaded during the hottest times of year, either by the branches of trees, or from man-made structures. This requires careful observation of conditions at different times of the day, but it’s time and effort well spent. Of course, an advantage of shading tree limbs is that they don’t create as much shade in the winter, when it isn’t needed.
A look at overall exposure can be useful too. When oriented upon a north/south axis, the greenhouse will receive more even sunlight, heating up less at the hottest times of day. One built on an east/west axis heats up more quickly in winter and early spring, but it will require greater ventilation and shade during the hottest summer days. So, deciding which seasons you will most use your greenhouse can be important.
Even if your greenhouse sits in full sun, it’s still possible to create shade inside. Some time-tested methods for creating interior barriers to sunlight are the use of greenhouse whitewash and roll-up shades. Hartley’s own retractable roller blinds are a particularly elegant example of the latter, precisely designed to fit the Victorian Range of Hartley Houses. Whitewash is easily obtained from other greenhouse suppliers or if you’d like to make your own, check the internet for recipes.
Regardless of the shading methods you employ, don’t forget ventilation; not only do vents help cool things off, they’re essential to the success of any greenhouse structure. Important considerations include whether they will be automated— a requirement if you are frequently absent, and also how many are necessary for the maintenance of appropriate temperatures . Addressing these concerns before building begins will help to make this the greenhouse of your dreams.