Sweet peas are a summer flowering annual.
This means that they germinate, grow, flower, set seed and die all in one year and have to be re-grown each year. Sweet peas are long flowering and provide colour, scent and flowers to pick for months. Sweet peas are not difficult to grow, but they need regular attention throughout the summer to dead head, take off the tendrils, train and tie them in. For this reason, they are a red wheelbarrow plant.
The good thing about sweet peas is the more you pick, the more you get. You can remove every bloom from a set of Sweet peas and within days they will be back, so keep picking.
Sweet peas are best planted in full sun in rich, moisture retentive soil.
Removing the spent flowers prevents the plant from making seed, which keeps it producing more flowers and prolongs the flowering season. Sweet peas require extra attention if you want straight stems. It is necessary to remove the tendrils regularly, see more below and a video.
If you encounter problems growing Sweet Peas, the most common problem is powdery mildew, a fungus which leaves white powder on the leaves. This fungus is much more likely to attack the plant if it is dry, which is why it is important to water sweet peas, especially during dry periods and to have plenty of organic matter in the soil to retain water. There is a Sunday gardener Video How to plant and grow sweet peas.
Sweet Peas are a popular choice for planting in containers. All plants grown in containers dry out more quickly, which makes Sweet Peas prone to attack by mildew. If you are growing Sweet peas in containers, consider adding water retaining gel and a good mulch to retain moisture. It also follows they will require regular watering, especially during dry spells.
If growing annual Sweet Peas is too much trouble, check out the Everlasting Sweet Pea which has the same lovely delicate flowers, albeit not scented, but as a perennial will return reliably and flower year after year.