I am SO confused about how to determine what is wrong with a plant by its leaves. I can't seem to find anything online that exactly matches what I see. Or a database of leaf issues that I can scroll through. If anyone doesn't mind, could you help me figure out what is going on with my garden? I have attached pictures:
1) Tomatoes. The two plants are in the same planter and started out as the same size. I feed them the same food and water them at the same time, but the plant that is on the left is much shorter and just developed those weird veiny leaves. My research seems to indicate that it needs chelated iron?
2) More Tomatoes. Is this blight on the tomato? The leaves develop brown spots and edges then yellow fills in the leaf. All five of my tomato plants develop this on their bottommost branches. I cut them off when that happens, but if I keep this up, I will have naked tomatoes! Should I be applying a fungicide or is this just life with tomatoes?
3) Squash. My squash leaves are turning yellow. It starts out on a healthy green leaf as a splotch and then the entire leaf turns yellow. There are a few tiny brown/rusty spots. Is this a fungus?
4) Cucumbers. At first it was the bottommost leaves on my cucumber vines that developed the weird points and then yellow splotches, but now it is moving on up the plant. I cut them all off this morning, but don't know if more will develop. Do the older leaves just die off? Or is this a fungus, too?
5) Bee. The happy bee paused for a photo op. I had to share her with you.
Thanks in advance for any help.