I got one quince plant(double take pink storm from PW) in early spring, then plant into a big pot in backyard(16-18 in diameter) . It has at least 8 hours full sun and now it is turn to hot in San Jose(zone 9, 75-85F). It starts grow quickly and flowering a lot, I thought it is strong and didn't pay attention every day. Recently I found aphids then applied the selvin pesticide(some leaves still show a little white powders).
And I also notice watering every week in this hot climate may be two dry for the quince.Because I found the inter leaves seems all yellowed and dried. So I start to water every 3-4 days when top soil become dry for some time. It start to show signs to grow better now. However it developed black spots on the leaves, not sure if I need to treat that? Am I watering too much? Also I noticed quite some spider nets like threads around the plants(see the last photo), not sure it that matter?
Photos attached. Thanks in advance!