Almost Black<\/a>.<\/p>\nHow Late Can You Plant Sweet Peas and Still Get Flowers?<\/h2>\n
Sweet peas sown outdoors as late as early April can still produce a good flush of flowers before the summer heat triggers their decline, but anything planted after mid-May will give a disappointingly short season.<\/p>\n
Sweet peas flower from the base of the plant upward and then stop once temperatures consistently exceed around 25\u201327 \u00b0C for extended periods, which in the UK typically happens in July or August. A plant put in the ground in May has far less time to build stems and root mass before the heat arrives than one planted in April. If you have missed the optimal window, choose fast-maturing varieties, keep plants well watered, pick flowers every two to three days to delay seed set, and accept that the season may run from early July to August rather than from June onwards.<\/p>\n
Can You Sow Sweet Peas Directly Outdoors?<\/h2>\n
Yes \u2014 you can sow sweet peas directly into the ground in March and April once the soil has reached at least 10 \u00b0C, though indoor-raised plants almost always perform better and flower earlier.<\/p>\n
Direct sowing works best on well-drained, fertile soil in a sheltered, sunny spot. Sow seeds 2\u20133 cm deep and about 10 cm apart, thinning to 20\u201325 cm once they have two or three pairs of leaves. The main risk is slug damage to the emerging shoots; scatter organic slug pellets or use wool mulch around the emerging seedlings. Mice are also fond of sweet pea seeds, particularly in autumn \u2014 if this is a problem, sow in pots under cover and plant out as seedlings.<\/p>\n
When Should You Prepare the Soil for Sweet Peas?<\/h2>\n
Prepare the planting site the autumn before if at all possible \u2014 or at least four to six weeks before planting \u2014 so that organic matter breaks down and the soil settles before the plants go in.<\/p>\n
Sweet peas are deep-rooted and hungry plants that reward thorough ground preparation. Dig a trench at least 30 cm deep (some exhibitors dig 60 cm), incorporating well-rotted garden compost or manure at every spade depth. This not only feeds the plants but dramatically improves moisture retention, which is critical in dry summers. If you are preparing in spring rather than autumn, use bagged organic compost and allow it at least a month to integrate before planting. A handful of bonemeal forked in at planting time gives a gentle, long-release phosphate boost to encourage strong root development.<\/p>\n
Which Varieties Are Best for Autumn and Spring Planting?<\/h2>\n
Almost all heritage and Spencer varieties suit both planting windows equally well; variety choice is better guided by colour, scent, and stem length than by season.<\/p>\n
That said, some varieties have particularly robust constitutions that help them stand up to the variable conditions of an autumn or early spring planting.<\/p>\n