Cupping leaves--too wet or too dry?
I'm hoping you all can help me determine what is causing my pawpaw leaves to cup up and curl. Please see photos. Is it too wet or too dry? I was trying to use moderate watering. I am experimenting with several mixes. Note that one is a 1:1 peat:sand mix, the other is in 5:1:1. The worst tree is in the peat sand mix, and perhaps that is telling us something. A third mix used is 9:1 pine bark:compost, and those trees, while some are cupping, look the best. Again, another clue? While my first reaction to the leaves is that they look dry, perhaps because the faster drying mixes look better, is there too much moisture?
I am using dowels to help me with moisture levels, and the bottom half of the containers seem plenty moist. The containers are Rootmaker, and the mixes contain Osmocote at a rate of 12 lb/cubic yard--about 2 tabs/gallon. Small amounts of micronutrients are also in the mix. Some acid is being injected into the water. Newly-germinated pawpaws in 5:1:1 in Rootmaker 18s look great. Thank you for any ideas.