Cold frame - Feb-April. In the garden: from the end of April.
2 ways to sow:
- x x
- xx Sow lathyrus early - from the start of February, indoors. Use small pots and sow one seed per pot. Stand them in a propagator or just on the window sill. Keep them warm and moist, and light will germinate them. Slow the growth indoors by standing them in a cooler spot, but do give them enough light.
x x x
- x x
- xx Sowing in the garden - preferably in full sun they can last from April, all the way through to June. Loosen the soil with a fork up to 30 cm deep. Draw a straight furrow 1 cm deep. Label the row and sprinkle the seed along the row - sow as thinly as you can. Cover the seed with 0.5 cm soil, press carefully down and sprinkle with water. Extra rows should be set at 30 cm apart. Your seedlings should be given frost protection. If the intention is to leave the plants where they were sown, do give them something to climb up - chicken wire along the row connected to poles at either end will suffice. These plants will climb themselves.
Once the seedlings are 10 cm tall and frost is no longer forecast, plant them where you want them.
The soil should be nice and loose. Water your Lathyrus immediately. Climbing sweet pea will thrive in loose and fertile soil. Improve poor garden soil with some added manure. Full sun or part shade.