The best annuals for continuous cutting

Annuals are your engine. They grow fast, flower young, and respond to cutting by branching and flowering again. The trick is choosing varieties bred for the vase, not the border. Cosmos 'Purity' and 'Rubenza' have strong 70cm stems and last a week in water. Cornflowers in the 'Classic' series reach 80cm and keep producing side buds even after the first flush. Cerinthe major 'Purpurascens' gives you grey-blue foliage and nodding purple bracts from a single plant for three months.

Succession is everything. Sow a small pinch of seeds every three weeks from March to July, and you will never have a gap. Sweet peas are the classic example: a first sowing in October (in pots, overwintered in a cold frame or sheltered spot) flowers in May; a March sowing flowers in July. Calendula, larkspur, and nigella can all be sown in autumn or spring — the autumn batch flowers earlier and taller. If you only have space for one container, sow it in three staggered batches, thinning to the strongest seedlings each time.

Do not overlook the heritage and cottage-garden strains. Sweet peas like 'Matucana' (maroon and violet, intensely scented) and 'Painted Lady' (the 1737 bicolour) have thinner stems than modern Spencers but better fragrance and longer vase life. Nigella 'Miss Jekyll' is the tall, pure-blue form that florists want — not the dumpy mixtures sold for borders. Ammi majus and Ammi visnaga are the airy white umbels you see in every artisan bouquet; both self-sow reliably and tolerate partial shade.