Since I'm new to potato growing, I am hoping someone with a bit more experience can help me figure out what--if anything--is wrong with these potato plants. They have been happily growing in their bags over the last month or so, but, all of the sudden, things seem less promising.
I have two primary concerns:
(1) Their stalks have flopped over.
(2) They don't seem leafy enough.
I had been trying to keep the soil in the potato bags moist, but I also don't want to over-water them. Now, I'm not sure whether I need to water more or less. I added about an inch more compost to the bags, in case that would help, and also fed the potatoes with some liquid organic fertilizer that is high in potassium. I haven't seen any bugs hanging around, so I don't think they're under attack by a garden pest.
I have removed quite a few yellowing, dying leaves from the stalks. And some of the leaves currently on the plants look like this:
Usually I don't worry too much about dropping leaves, but the potato stalks look really bare. Could they have some sort of leaf blight? I was thinking it might be too hot for them, but it's really only gotten into the 90s a couple of times this summer, and my gardening book says potatoes are pretty happy up to 85 degrees. So, what could be bothering my potato plants?
As you can see, I'm feeling a bit anxious about my potato crop. To be honest, I'm into the nervous phase with my entire vegetable garden. Everything is producing baby fruit, but nothing has ripened for harvest yet. I have had several experiences in the past where everything goes wrong at this particular phase--withering squash, pepper flowers that won't make fruit, blossom-end rot on tomatoes--so I'm worried. This is the phase where I start reading gardening message boards and getting confused by conflicting advice about nitrogen levels and how many inches to water your zucchini. Perhaps I just need to chill out.
But anyway... Does anyone have some potato growing advice? Should I be concerned about the floppy, spindly plants? Or should I just calm down and cross my fingers that tubers will eventually form inside those big green bags?