This is a picture of a Camellia with leaf gall. Camellia leaf gall is a fungal disease caused by excessive moisture and poor air circulation.
If you have an existing Camellia that is already diseased it might be caused by all the recent rains. Poor pruning practices and/or not enough sunshine can exacerbate and make it worse. While you cannot control the crazy weather, you can take some simple steps to manage the disease without using chemicals. (https://hgic.clemson.edu/camellia-leaf-gall/)
Here are our best management practices for existing Camellias:
First, pick off/prune the affected areas and put in the trash. Do not compost or leave the cuttings nearby other Camellias. This fungal disease spreads when the fungal spores are released into the air and soil. They will lie dormant until the next year. Leaf gall will not kill a Camellia but the plant and any nearby will be more diseased the next year if the affected areas are not taken care of. Make sure to sanitize your pruners afterwards with alcohol.
Secondly, allow light and air to penetrate and circulate inside the shrub. The Camellia in the following picture has been over pruned with hedge trimmers so there is no light or air inside the shrub. This is the perfect environment for diseases and insects to take hold.
The simplest way to allow air to circulate inside the plant is to thin it out. We do this by pruning selective branches by hand. The shrub in the next photograph was sheared every year causing excessive growth on the outside of the shrub and no light inside. We pruned some of the branches; notice how in the following photo the shrub looks more open.
Thirdly, make sure that there is not a mulch ‘volcano’ around the trunk of the Camellia. The following picture shows the wet trunk caused by too much mulch. Wet trunks can also cause rot which will could eventually kill a shrub or tree.
Go check out your Camellias and if you need help, please call Suzanne at Art of Stone Gardening.