Sweet pea

The sweet pea is an annual and dies with the first frost. It cannot be overwintered, only its seeds can. In late summer let some pods ripen, harvest the seeds, store them dry and cool and start them indoors from February/March, or sow directly in the bed from March/April.

You propagate the sweet pea exclusively by sowing. As an annual, it forms no runners, bulbs or rhizomes that would allow vegetative propagation. For an early start, begin from the end of February to early March: you can soak the hard-coated seeds beforehand overnight in lukewarm water or lightly roughen them with sandpaper; both speed up germination but are not strictly necessary, and many varieties germinate reliably untreated as well. Sow them singly 2 to 3 cm deep in deep pots or root trainers, since sweet peas form strong taproots early. Keep the soil evenly moist, but not wet. At about 15 to 18 °C the seeds germinate within 1 to 3 weeks. In a bright, cool spot (around 10 °C), compact, robust young plants develop. Warmth does promote germination, but leads to leggy, weak shoots. When the seedlings have about three pairs of leaves, pinch out the shoot tip, which encourages bushy branching. From mid-May, after the Ice Saints, plant them out in a full-sun spot with a climbing frame. Alternatively, direct sowing outdoors from mid-March to April also works; it then flowers somewhat later. In mild areas, autumn sowing is even possible: the ungerminated seeds survive frosts, and the plants root in well before winter and flower earlier. To stretch the flowering season, you can sow again every four weeks.