Marrows are one of the cucurbits along with squashes, cucumbers and courgettes and are essentially large, matured courgettes. You can buy marrow seeds that are cultivated for that purpose, and you can also leave courgettes to grow larger, which it then becomes a marrow. You can also refer to Courgettes page.
Marrow or courgette seeds are sown sideways to prevent them rotting in soil. They can be started in pots, indoors or sown directly outside later, once the threat of frosts has passed.
Marrows are a hungry and thirsty plant, and so regular watering during dry spells in nutritional soil. Once the plant is flowering you can use tomato feed to regularly feed the Marrow or Courgette plant.
You will not get as many marrows per plant due to the energy going into growing the larger fruit. Courgettes are picked more regularly when they are immature and so this encourages re-growth. You will likely get approximately 4 marrows per plant.
Marrows will be ready to harvest from July-October. You can cut them off the plant at the stalk and leave in the sun for the skin to ripen and harden.
When using Marrows, the seeds and middle section is removed, leaving the flesh and skin. It is a popular vegetable to stuff with spicy meat fillings and can also be added to soups, curries and other dishes.