Popular for their scent and attractive blooms in a wide range of colours, sweet peas are deservedly garden favourites. However, they can succumb to a number of problems
Lathyrus odoratus (sweet pea) was introduced to the UK around 1700. Primarily grown for their scented flowers, sweet pea selections can be seen in gardens and allotments across the country. They are, however, prone to a range of problems, but these can be addressed.
Sweet pea seedlings can become leggy if their growing conditions are too warm or light levels are too low. Pinch out the tips of young seedlings to encourage bushy plants. Sweet peas should be grown in cool but frost-free conditions.
Powdery mildew (right) can be caused by dry conditions around the roots and poor airflow around the plants. To help prevent the spread of this fungal disease, avoid wetting foliage,
and spray with an appropriate fungicide at the manufacturer’s recommended rates.
Sweet peas are also prone to viruses that may be carried within the seed. Even if only one seed in a batch is infected with a virus, aphids can quickly spread the problem to other plants after germination. Virus-infected plants are best removed and destroyed.
Scorched foliage can be caused by drought or temperature stress.
Flower-bud drop can be caused by cold nights, drought stress and pesticide application.
Foot rot of seedlings can be avoided by always using clean compost.
Control aphid attacks with an appropriate insecticide.
Although they are harmless, pollen beetles can also gather in blooms. There is no chemical control, but vases of affected flowers can be placed in a dark room with a light source at one end: the beetles may be attracted to the light and should leave the flowers.
Sarah Durrant