Highbush blueberries (Vaccinium corymbosum) differ from wild bilberries in one way that matters to gardeners: they grow only in acid soil with a pH of about 4.0–5.5. In ordinary garden soil, dig a wide planting hole or use a large pot and fill it with ericaceous compost or composted pine bark, then plant in spring or autumn. Grow at least two different varieties close together, as cross-pollination gives larger crops. The roots are shallow and fine, so mulch 5–10 cm deep with pine bark or needles and water with rainwater – hard tap water gradually raises the pH and causes yellow leaves. Feed only with acidic fertiliser and stop by early July. Berries ripen gradually in July and August; pick them when fully blue and net the bushes against birds. From the fourth year, remove a few of the oldest, least productive stems at ground level in late winter. Blueberries also tolerate light shade.