hi, all. new to the forum and to gardening; been serious about my green thumb for only a few months. thanks to the forum members for the blackberry edumacation i've acquired as i lurked.

i'm in zone 10, and for the past 1.5 months, i've been growing two prime ark freedom plants, one from hirt's, another from hello organics. the hirt's plant recently exhibited browning of the leaves; the most affected leaves are curling at the edges. was wondering whether someone could help me, please, in diagnosing the problem. does it look like an infection? an infestation? (i don't see any critters.) neither of the above? do i need to trim these leaves?

some thoughts: possible fertilizer burn, since i recently used a couple doses of miracle gro liquid plant food, albeit only a few drops diluted in plenty of water. another thought: i recently moved the plant from a relatively shaded place to a sunnier spot, which suddenly increased the amount of sunlight it received from about 5-6 hours per day to 7-8 hours per day. did this stress the plant?

the temperature was recently in the 90s. could this be a dehydration issue?

other notes: not all the leaves are affected. there's still new growth going on, so the plant isn't dead. there are some older leaves which have yellowed a bit, but i'm guessing that's due to usual senescence.

thanks in advance for any help!