For any early start sow the seeds singly, edge on, about 0.5in (1.25cm) deep, in small pots and place in a temperature of 65-70°F (18-21°C). After germination grow on in a well lit spot, harden off and plant out after the last spring frost when the weather is warm.
A sunny, open site with humus-rich soil that is never allowed to dry out is ideal for this crop. Six plants spaced 3ft (1m) apart each way will give self-sufficiency in courgettes for a family of four, while four marrow plants will give an adequate supply. Cut courgettes when 4-6in (10-15cm) long and marrows when the skins can still be readily marked with the thumbnail. A weekly feed with a liquid fertiliser ensures a steady supply of young fruits.