Sowing in Succession: A Simple Calendar for Cut Flowers from April to October

The single biggest difference between a garden that produces a few nice bunches and one that produces flowers all season is not space, skill, or variety. It is succession. Most people sow everything in spring, watch it all bloom in July, and then spend August wondering what went wrong. The fix is simple, and it costs nothing but attention.

Succession sowing means sowing the same crop at intervals — usually every two to three weeks — so that the harvest is staggered. It works best with annuals that have a short flowering window, and it works less well with plants that bloom continuously anyway. Knowing which is which is most of the battle.

What to sow in succession

Annuals with a defined bloom period benefit most. Cornflowers, calendula, nigella, larkspur, and most of the hardy annuals will give you three or four weeks of flowers and then stop. Sow them in March, again in April, and again in May, and you will have them from June into September. Sweet peas are the same — sow a first batch in autumn or early spring for early flowers, then a second batch in late spring for late ones.

Zinnias and cosmos are slightly different. They will flower for months once they start, but they take a long time to get going, so the trick is to start them early indoors and then sow a second round directly in the ground in early summer. The second round catches up just as the first begins to tire. Dahlias are not annuals at all, but treated as cut flowers they behave like them — plant a few tubers in April, a few more in May, and you will have blooms into the first frosts.

Some plants should not be succession-sown. Sunflowers, for instance, are usually better as a single sowing, because later sowings produce smaller plants that never quite catch up. The same goes for most biennials, which need a full year to build. Learn the exceptions and the system becomes much simpler.

The practical rhythm

I keep a simple rule: one sowing a fortnight, from early spring to midsummer. That is roughly eight sowings, which sounds like a lot until you realise each one is small — a half-tray, a short row, a few pots on a windowsill. The point is not volume. The point is continuity.

Watering matters more with succession than with a single sowing, because you always have seedlings at a vulnerable stage. Keep them close to the house if you can, where you will notice them. Label everything — it is astonishing how quickly you forget which tray is which. And accept that some sowings will fail. A late frost, a dry week, a slug — something will get through. The system absorbs losses that would be devastating if you had only one sowing.

By October, if it has worked, you will have forgotten which flowers came from which sowing. You will just have flowers, week after week, and the garden will feel generous in a way that has nothing to do with how much you planted. That is the reward for thinking in time rather than in space.