Deformed new leaves on my bilberry (european blueberry) plants

Question

I have some bilberry plants (european blueberry, Vaccinium Myrtillus) growing in containers on my balcony, and I just noticed that new leaves are deformed and discolored (a bit more yellow that the rest of the plant).

Some images:

Some more context:

• The soil has a Ph of approx. 4.5 (according to the vendor)
• It has been very sunny and hot in the last days (more than 25° C ambient temperature, perhaps more than 30 on the balcony)
• The blueberries are under direct sunlight from early in the morning to about 4pm
• I am watering lightly with distilled water and vinegar (1ml/l) once every few days if it doesn't rain. The solution should have a Ph of around 4
• Last week I have inoculated the roots with ericoid mycorrhiza

Can please someone help? Should I fertilize/water more?

Thank you.

EDIT:

The crinkled new leaves seem to grow up healthy and overall the plants are doing great.

Answer 1

I've seen this happen for 2 different reasons. When I buy plants from a nursery that uses synthetic fertilizers and I use organic. And when I take them outside in the spring. If you're watering every few days with vinegar your probably getting too acidic. These 2 links may help. I've used baking soda on my plants forever. I don't mean any harm, I use vinegar to kill weeds. Vinegar, dawn dish soap and sugar is better than roundup.

https://www.fieldnotesbystudioplants.com/houseplants/why-does-my-plant-have-a-wrinkled-leaf

https://balconygardenweb.com/baking-soda-uses-in-the-garden-baking-soda-for-plants/