blueberries leaf issue - red tinged
i need your help! i have no idea what to do about my poor blueberries. they're struggling to keep going on, and i cannot tell if this is due to mites, hot summers (90ÃÂ°f+), pH or what.
i've read that ideal soil pH for blueberries is acidic, between 4.5-5.5 is ideal. i've been taking readings and some places get down to 5.8, but most are ~7.0 (my meter is an electronic tester).
to correct this, i've used aluminum sulphate to drop the ph -- supposedly it could take a week to see the change in the surrounding affected soil. i water these blueberries once a night, or every other night. i've applied alaska fish fertilizer to them approximately 4 weeks ago and have observed very little change.
tldr: what does this leaf discoloration tell you folks?
lastly -- my appologies for not being able to zoom in further on leaf discoloration, using smartphone cam digital zoom loses detail.