Sweet cherry (Prunus avium) grows into a large tree unless it is grafted onto a dwarfing rootstock such as Gisela 5, which keeps it at about 3–4 metres and brings it into bearing sooner. Plant bare-root trees in autumn or early spring in deep, well-drained soil (pH 6.0–7.0) in a sunny, open position; waterlogged ground causes gummosis. Most varieties need a compatible pollinator flowering at the same time, although self-fertile varieties such as 'Stella' or 'Sunburst' crop alone. Cherries flower in April, so late frosts can damage the blossom. Unlike apples, cherries are best pruned in summer straight after harvest, when wounds heal quickly and infection is less likely. Pick the fruit when fully coloured, ideally with the stalk; ripe cherries split after heavy rain, and birds strip unprotected trees, so net smaller ones. Cut out shoots killed by brown rot (Monilinia) well into healthy wood, and hang yellow sticky traps against cherry fruit fly.