Sweet Peas and Mildew

powdery mildew on sweet peas

Do your sweet peas always end up looking like this, or similar, but maybe not so bad.  This is powdery mildew, which can be a real problem with Sweet Peas, and probably, at some point, in the season they will become infected, it is almost inevitable. What we can do is fight it off until, hopefully, towards the end of the growing season when we have had time to enjoy the wonderful colour, scent and blooms before the mildew gets the edge.

Illustrated is a bad attack of mildew, and by this stage there is not much to be done, but dig them out.

The key to preventing, ameliorating, or reducing mildew is:

  • plant in organically rich soil, which is moisture retentive.
  • good air circulation so do not plant to densely.
  • Do not to let the plants dry out, water well in dry spells.

The mildew attacks the plants when they become too dry or otherwise stressed. Sweet peas are hungry feeders, and they like plenty of water. Also, when we plant sweet peas, we tend to pack them in, for mass colour effect, and we plant too many too close.

So what to do?

First, plant sweet peas in a part of your garden which is the least dry. Gardens are not uniform, there are slightly different growing areas, and one area will be less dry than another.  Before planting, add lots of organic matter so the soil holds moisture. Once planted water, water, water, if the days are dry. Mulch the soil to retain the water. Sweet Peas are very susceptible to becoming over dry and this sets off mildew.

Given the watering requirements, especially in drier areas of the country, it may be time to consider if Sweet Peas are the best annual to grow.

Sweet Peas are a popular choice for planting in containers. All plants grown in containers are prone to drying out more quickly. 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.

See also

How to Grow Sweet Peas and video

How to get straight stems on sweet peas

Video Removing tendrils from sweet peas

Updated 02.11.2021