Fruit scientists in Wisconsin and Ohio have performed parallel experiments on the strawberry 'Earliglow' to see how sunlight affected growth. They weren't really looking for ways to increase yields, but one of their test plots yielded about 15 percent more fruit the next year.
The yield increase came from shade. The researchers covered strawberry beds with 60 percent black shade cloth on wire hoops for about a month during various parts of the growing season. Yields the next year were from 13 to 17 percent higher than those in unshaded beds.
The benefit is most pronounced if weather is hot and dry during bud set. In the North, this period is short and will determine the season's harvest. Research suggest that gardeners in western and southern regions, where hot and dry summers are typical, are most likely to see benefits.
Photography by National Gardening Association.