Landscape view across agricultural fields of courgettes planter in lines and rows under plastic to prevent pests on 17th June 2020 in Hartlebury, United Kingdom. The zucchini or courgette is a summer squash, of Mesoamerican origin, which can reach nearly 1 metre in length, but is usually harvested when still immature at about 15 to 25 cm. A zucchini is a thin-skinned cultivar of what in Britain and Ireland is referred to as a marrow.