The same cool - time of year vegetable that delight gardeners in the outpouring can bring alarm at the height of summer . That ’s because many early heraldic bearing " cool weather crops " tend to bolt during the elevation of summertime . you could forbid these veggies from turn bitter or woody by using shade textile . Most commercial-grade shade textile makers betray their product by the percentage of sun occlusion it provide . Use either hoop sign of the zodiac , tunnels or wooden frames to drape the shade cloth .
Lettuce
A study conducted by Kansas State University and the Organic Farming Research Foundation determined that lettuce and leafy green yield and caliber increase enormously through the use of simple tunnel frame covered with 39 percentage shade material . A command group of lettuce and leafy greens implant in steady field fare much more poorly . " Shade - grown lettuce and leafy vegetable produce declamatory , quicker than their open - field - grown counterpart , and appear to have consistently mellow quality , being consistently cleaner ( due to lack of rain splashing ) and more succulent , " the study conclude . The research observe that both head - type cabbage and the varieties that can be harvested throughout the time of year do good from shade cloth .
Mother Earth News points out that a homemade adaptation of nicety cloth , using two sheets of smuggled nylon netting , provides about 30 percentage shade . Adding lightweight cotton provides even more protection during very hot weather condition .
Sorrel
Sorrel , with its heavy leaf and lemony zest , lends itself well to the kinds of pureed soup and sauces that taste peculiarly refreshing on hot summer nights . And sorrel plants continue to produce those leaf from very early spring to tardy fall . The only problem ? Sorrel tends to go to seed when exposed to too much warmth . Use ghost textile much the same way you would with lettuce crop . But because sorrel is a perennial veggie , you might want to take more fear localize up a tunnel or lift - bed system . prefer Rumex acestosa , the classic garden rozelle that grows about 3 feet improbable and has tumid leaf , or low - raise Rumex scutatus ( Gallic dock ) , whose modest parting work on best in salads rather than as a manipulate green .
Cooking Greens
Along with Hibiscus sabdariffa , many other cooking putting green tend to stand in high heat , admit spinach , mustard super C , colewort and collard Green . Even sturdy Swiss leaf beet appreciates tincture fabric in excessive heat . Extend their time of year by using 39 percent ghost cloth – more in extremely hot regions or during unusually hot weather . Continually constitute new seeds in adjacent beds to enable whole - plant harvesting for several months in a row .
Broccoli
Brassica oleracea italica treats gardeners to gratifyingly former harvest time of year , but will bolt if not harvested chop-chop enough . This is a shame , because broccoli ’s time of year can be extended by plainly collecting its side shoots , rather than going the " off with their heads " whole - plant harvest routine . The former method only work when the plant are prevented from bolting . Use 30 to 45 percent wraith cloth to keep yourself in Brassica oleracea italica shoots for calendar month .
Other Vegetables
Other coolheaded - season crops that may do good from shade fabric include cauliflower , pea , celery and celeriac .
