Powdery mildew on peas is a common problem, particularly as conditions become warmer towards spring. It appears as a white, powdery coating across the leaves, stems and sometimes pods.
The disease is also common towards the end of a pea crop’s life, when older plants naturally become less vigorous. Whether it’s worth treating depends largely on the age and productivity of your plants.
1. Assess your pea plants
If your plants are still young and have plenty of growth and production ahead of them, it’s worth taking action to manage powdery mildew on peas.
If the plants are nearing the end of their productive life and you’ve already enjoyed a good harvest, treatment may not be worthwhile. In this case, harvest the remaining peas and prepare to remove the crop.
2. Remove badly affected leaves
Remove leaves that are heavily covered in powdery mildew to help reduce the amount of fungal material around the plants.
Avoid removing too much foliage at once, as the plant still needs healthy leaves to support growth and pea production. Dispose of infected material rather than leaving it around the garden bed.
3. Apply a suitable organic fungicide
Treat young, productive plants with an organic fungicide labelled for use on peas or edible crops. Suitable options may include wettable sulphur or an eco-fungicide.
Follow the product label carefully, including application rates, withholding periods and temperature restrictions. Some sulphur products can damage plants when applied during hot weather or too close to an oil-based spray.
Continue monitoring your plants and reapply the treatment as directed on the label, particularly after rain.
4. Improve airflow around your peas
Powdery mildew on peas is encouraged by warm conditions, high humidity and poor airflow. Thin crowded growth where practical and make sure the vines have enough space and support.
Water around the base of the plants to keep moisture in the root zone. Although powdery mildew doesn’t require wet leaves to infect plants, avoiding unnecessary overhead watering can help reduce other fungal problems.
5. Remove plants when production finishes
If your pea plants are reaching the end of their productive life, don’t stress too much about treating them. Harvest any remaining peas, pull out the plants and make space for your next crop. When you’re ready to sow again, follow our guide on how to grow peas for a bigger harvest.
Dispose of badly infected plants rather than leaving them in the garden. Depending on your climate, replace them with lettuce or silverbeet in cooler areas, or bush beans and eggplants in warmer districts.
Powdery mildew on peas can look alarming, but it doesn’t always require intensive treatment. Focus your efforts on young, productive plants and remove older crops once they’ve finished producing.
