Tomatoes

"it's difficult to think anything but pleasant thoughts while eating a homegrown tomato."
- Lewis Grizzard
Difficulty rating: easy
Suitable growing site: open ground or large pot - balcony, garden or allotment.
Days from sowing to harvesting: approximately 90 days, but depends on variety.
Risk of cross-pollination: low
When to sow: indoors in February, or March and April under glass. 
Requirements: good soil, regular water, full sun, occasional fertiliser.
Harvesting for eating: as fruits ripen in late summer and early autumn.
Harvesting for seed: when fruits are fully ripe in late summer and early autumn.
In this video, Vicky explains how to save seeds from tomatoes: