Sunflower

The sunflower is annual and dies with the first autumn frosts. You do not need to overwinter anything, but you sow anew in spring (from mid-May, after the Ice Saints, week 20). Feel free to leave the stems standing over winter: the seed heads feed the birds, and if you want seed yourself, cut off a fully ripe head and let it dry further in a dry, airy place.

You propagate the sunflower exclusively by sowing, since it is annual. You have two routes: raising in pots indoors from the end of March (soil temperature at least 12 °C, bright position); this way the plants flower 2 to 3 weeks earlier and are protected from slugs. Pot them on singly, because the taproot tolerates pricking out poorly. Alternatively, sow directly outdoors from mid-April to mid-June, as soon as the soil is frost-free and has warmed reliably above 10 to 12 °C; after the Ice Saints (mid-May) you are on the safe side. Press the seeds about 2 to 3 cm deep into nutrient-rich, deep soil and keep at least 30 cm from the next plant. With staggered successive sowings 2 to 3 weeks apart, you extend the flowering period into autumn. If you want to collect your own seed, let one flower head ripen and dry fully before you harvest the seeds and store them cool and dry. Note: only open-pollinated varieties come true to type; from the seeds of F1 hybrids you do not raise identical plants.