Winter Pruning Your Apple Tree? Watch out for Brown Rot and Apple Canker

Apple trees are typically pruned in the winter to keep them productive and at the desired size. Winter apple pruning is also the perfect time to identify and treat apple tree fungal diseases such as brown rot 🍏1️⃣ (Monilinia species) and apple canker 🍏 2️⃣ (Neonectria ditissima). By taking action in the winter, you can keep your apple tree healthy in the coming year.

🍏1️⃣ Brown rot symptoms: rotting, brown, mouldy fruit are most obvious in the autumn. However, the brown rot fungus also overwinters on so-called ‘mummified fruit’ on the apple tree. I’ll show how to spot these mummified fruit and what you should do with them.

In the UK, brown rot is caused by two different fungal species, ‘Monilinia laxa’ and ‘Monilinia fructigena.’ A third Monilinia species, ‘Monilinia fructicola,’ causes similar symptoms of brown rot elsewhere in the world.
Thankfully, ‘Monilinia fructicola,’ hasn’t yet been found in the UK - thank goodness!

The brown rot fungal species Monilinia laxa can also cause symptoms on the tree in the spring with a separate disease called Blossom Wilt.

🍏 2️⃣ Apple canker symptoms: These symptoms are most easily spotted when the leaves have fallen on your apple tree. These ugly, dark sunken and damaged areas of bark on the apple tree stand out from the healthy branches.

Once you learn how to spot the symptoms of these apple canker lesions you can take steps to protect the health of your tree.

Branches above apple canker lesions eventually die-back and the fungal disease will reduce fruiting. The sunken lesions often develop small, red, pin head sized fruiting bodies (known as fungal perithecia), which produce spores allowing the fungus (Neonectria ditissima) to spread.


⌚ Timestamps:

00:00 Beware of these 2 diseases when winter pruning apple trees
00:13 Spot and treat apple brown rot symptoms
00:42 Spot and treat apple canker symptoms
01:30 Clean your gardening tools!

Please note: Thoughts shared in this video are my personal opinions. I'm not paid any money to promote the gardening products I talk about or use here.

Happy gardening! 🌸