An asparagus spear selection and picking unit for a harvester of green asparagus has at least one pair of tynes which are mounted adjacent to, but spaced apart from, each other. The adjacent edges of the tynes are shaped to provide a tapered channel leading to the nip of a pair of soft conveyors mounted adjacent to each other and extending upwards at an acute angle relative to the horizontal. The height of the pair of tynes above ground level is adjustable. When a growing asparagus spear has a height sufficient for its tip to be guided into the nip of the soft conveyors by the tynes, its top is gripped by the soft conveyors. Shortly after being gripped by the soft conveyors, the tip of the spear activates a sensor (a microswitch or an electro-optical device) to generate a signal which activates a cutter to cut the spear at or near its base. The cut asparagus spear is then conveyed by a series of conveyors to be deposited in a required orientation in a skip, field basket or pocket being carried on the harvester.