Sorry I do not have answers to some of your questions,but hubby has one of those hanging thingys for his tomato-plants and the very lowest leaves are curling too,but there are a lot of tomatoes.
We really do not fertilize anything and I have a lot of flowers and bushes,if it has not rained,we water everything very well every morning.
The Morning-Glory spells trouble after what I've heard,kind of spreads everywhere.
I don't know why yours is not flowering.
The grass,we have given up,after the pesticide-ban,I did not use pesticide even before the ban,because of my cats.
My motto is,if it's green it's ok,but we do pull Dandelion and Crab-Grass.
I know,if you keep a nice thick lawn,you will starve the weeds.
The Lilac I have no idea why it's mildewy,but it happens sometimes late in the season.
See,not much help,but I tried
