Sunflower owners should turn their plants eastwards in order to attract more bees and produce a higher amount of pollen, a new study suggests.

       The yellow-petalled plants oscillate and tilt their heads according to a natural time cycle known as a circadian clock, which follows the sun. However, researchers have found that, as the flowers mature, they stop following their usual timings and begin to face east, which attracts more pollinators than those facing west.

       They also discovered that east-facing flowers produce more pollen, as well as larger and heavier seeds, to coincide with the time that bees visit.

       To carry out the study, the team from the University of Virginia, in the USA, took sterile male plants which could produce seeds but not make pollen and surrounded them with normal plants facing east or west.

       They then used genotyping to distinguish whether these were pollinated by east or west-facing plants and found pollen from the east-facing ones was responsible for more offspring.

       Stacey Harmer, professor of plant biology in the UC Davis College of Biological Sciences and senior author on the paper said: "It's quite striking that they face east. It's better for them to face east as they produce more offspring."

       In a series of experiments, Prof Harmer and her colleagues found east-facing flower heads were higher in temperature in the morning than west-facing ones – attractive to bees foraging in the morning. She said rays of direct sunlight also paint ultraviolet markings on the flower petals that are visible to bees but not the human eye.

       Sunflowers, known scientifically as helianthus annuus, blossom from midsummer through to early autumn. The sunflower oil market is estimated to bring in around ￡30million to the UK economy per annum.

       The study was published in the journal New Phytologist.