Here you will find a list of just some of the the many varieties to sow month by month.
WHAT TO SOW
Charles Unwins sweet pea seeds an exhibition variety, a soft salmon pink sweet pea with a cream base, large flowers on long stems. [...]
A mix of mild flavoured brassicas including mizuna, cabbage, kale and kohl rabi. Days to maturity 10-15 days. Ideal for salads and [...]
Low maintenance plants that look good all season from early summer until frosts, with blue scented blooms, dwarf strain with flowers up to 15cm long, [...]