Raspberries (Rubus idaeus) grow from perennial roots that send up canes living for two years. Summer-fruiting varieties crop in June and July on canes grown the previous year; cut those canes to the ground straight after harvest and tie in the new ones. Autumn-fruiting varieties such as 'Polka' or 'Autumn Bliss' fruit from August until frost on the current year's canes, and the simplest approach is to cut all their canes to the ground in late winter. Plant bare-root canes in autumn or March, 40–50 cm apart in rows, and support summer varieties on a post-and-wire system. Raspberries need humus-rich, moist but well-drained, slightly acid soil (pH 5.5–6.5) in sun or partial shade; they suffer root rot in waterlogged ground and turn yellow on alkaline soil. Mulch with compost or bark and water well while fruiting. Pick every two days in dry weather, as ripe berries spoil quickly, and watch for raspberry beetle grubs in the fruit.