Sunchoke/Jerusalem Artichoke dying leaves
I live in zone 11a. I planted Sunchokes this year, but they haven't done well. I have never planted them before, I got the tubers from the Farmers Market, so the variety is a mystery. Anyway, the lower leaves are continually dying. The top leaves look fine, the next few down have brown spots, below that, more brown and some holes, below that the leaves are totally dead. See pictures below.
I've searched around, but every website says that diseases and pests are not an issue. Contributing factors could be:
1. The spot where I planted them is only partial sun.
2. The bed I planted them in has a lot of clay soil, mixed with compost.
3. Last year the tomatoes I planted in that bed all got blossom rot. On the other hand, this year some tomatoes came up in that bed as volunteers. They have been my best, healthiest tomatoes. Weird.
Any ideas? Micro-nutrient deficiency perhaps?