Extending Sweet Pea Flowering.
Sweet peas require constant dead heading if they are to continue flowering. The more you pick sweet peas the more they flower.It pays to nip back some of the growing tips of sweet peas to encourage stocky freely flowering plants. Feeding sweet peas every fortnight with a dilute liquid fertilizer will also help extend the flowering season(stop feeding if they start to make to much leaf).Sweet pea flowering is triggered by a number of factors one of which is day length so at the end of July install some normal lights in your glasshouse on a timer and leave the lights on two hours after dark.This in effect as far as the sweet peas are concerned extend the day length and keep them producing flowers for a bit longer.Finally stagger the sowing of the seeds to give you a spread of mature plants later in the year