How to treat Purple Hebe with black spotted leaves?

ellie1234

Hi, 

We recently put in a new garden bed. My pink Hebes are doing well but my two purple ones are losing leaves and now have black spots on the foliage but not on the new growth. A local worker at a nursery suggested they may be too cold and too wet. The garden bed receives direct sunlight every morning for a few hours. Any tips to save these plants? 

Ellie 

EricL

Hello @ellie1234 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your Purple Hebe.

Your purple Hebes are likely reacting to a combination of environmental stress and possible fungal infection. The black spots on the older leaves while not appearing on new growth indicate that the plants have recently been under stress, most likely from excess moisture and cold soil, which is common in freshly prepared garden beds during cooler months. Hebes generally dislike sitting in damp conditions, especially if drainage is poor or airflow is limited, and purple varieties can be slightly more sensitive than the pink ones.

If your garden bed receives only a few hours of morning sun, it may not be drying out quickly enough, especially in winter or early spring. While that light is helpful, it may not be enough to fully evaporate surface moisture and keep fungal issues at bay. To help your Hebes recover, begin by removing the worst-affected leaves to reduce fungal spread. Dispose of them rather than composting, and try to improve airflow by gently thinning the plant if it’s dense. Avoid watering the foliage directly and only water the soil when the top layer feels dry.

To assist the plant’s recovery, you can apply Yates Rose Shield or Eco-fungicide, both of which are suitable for fungal leaf spots and safe for ornamental plants. These are available at Bunnings and can be used as needed just make sure to apply during dry conditions and repeat after rain if necessary. If you haven’t already, check that the soil drains well and isn’t holding water. If it's heavy or compacted, consider gently aerating around the plant with a hand fork to improve drainage.

Adding a light mulch, such as sugarcane or pea straw, can help regulate soil temperature and reduce further splash-back of fungal spores, but keep it clear of the base of the plant. Lastly, don’t fertilise heavily while it’s stressed, but a light application of Seasol or PowerFeed All Purpose can support root health and help it bounce back.

If you need further assistance, please let us know.

Eric