Blueberry rust is on the rise throughout Australia with ongoing wet conditions. At PlantNet® we notice an influx of questions about the disease during periods of widespread rain. To address these concerns, and concerns from newly impacted areas like WA, we have compiled 7 Tips to Preventing Blueberry Rust in Your Garden.
Before you start, you need to understand when blueberry rust grows best. Here are two signs blueberry rust might grow:
- Your blueberry is too wet – including around its leaves and soil. This may be from persistent rain or overwatering.
- The weather is warm and humid.
A combination of these mean you to be extremely observant with your blueberries! Thankfully, our 7 tips to preventing blueberry rust will help you avoid the problem altogether:
- Prune your blueberries in late winter to reduce the canopy density. Condensed leaves will capture moisture which increases the risk of rust.
- Plant your blueberries in a mixture of 50% azalea and camellia mix and 50% pine bark – pine bark increases drainage, and therefore decreases the incidence of rust.
- Move your potted blueberries undercover in periods of extreme rainfall – this allows them to dry out.
- Raise your blueberry pots off the ground using bricks or pot stands. This increases the airflow under and around your blueberry, allowing captured moisture to dissipate.
5. Spray a preventative fungicide before long periods of rain. Note: Always follow directions of use when handling chemicals.
6. Avoid spraying leaves with water when hand watering your blueberries.
7. Sanitize thoroughly if you have encountered blueberry rust before touching your rust-free blueberries.
Following these tips will give you the best chance to avoid blueberry rust in your garden. If you are experiencing constant rain and fear you can’t avoid rust or other diseases in your orchard, read our article on Preparing Deciduous Fruit Trees and Blueberries for Extreme Wet Weather.
Hang on – what do I do if my blueberry already has rust?
We hear you, and it happens to most blueberry growers at some point. Here are our 4 steps to getting rid of blueberry rust:
- Remove affected foliage. If the whole bush is affected, it’s wise to hard prune and start again – this avoids the disease consuming the whole plant.
- When the plant is dry, spray the foliage and branches with a mancozeb or copper fungicide. This will destroy the remaining fungal pathogen – if it doesn’t, repeat the treatment at the recommended interval.
- Remove leaf litter as frequently as possible and dispose of them responsibly (not in your compost bin!).
- Identify and treat or remove other plant species that may be harbouring and spreading the disease. Many of the plants that spread this disease are, like blueberries, in the Ericaceae family. For example, azaleas and cranberries.
Prevention is always the key to success – but occasionally life gets in the way of our blueberry growing and we must resort to chemical treatment! If your PlantNet® blueberries do get rust, you can be sure that these hardy varieties will bounce back if you follow these tips. If you need more advice, or need help identifying blueberry rust, Contact Us!