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?

[img][/img]

Normal, though not pretty.

That's normal? All the images I found on-line had healthy leaves all the way down. Well, I don't care about pretty as long as I get a decent harvest.

Well, I betcha they would be a bit greener next year with some more good compost added to the soil... The sunchokes that we had growing at the edge of our garden years ago looked like that at the end of the season. The ones that migrated into the garden looked a lot better for a longer part of the season. They are really hard to kill. And don't ever run a tiller through where they are... you will never get rid of them.

Here is a little bit more about them.
http://harvesttotable.com/2009/03/how_to_grow_sunchoke/

Thanks. They are in the worst spot in my garden. The soil is marginal and there is a lot of shade. I'll be amending with more compost over the winter.

They are isolated in their own bed, I doubt they will spread through the surrounding concrete-like clay. I'm not too worried if they get a little out of hand in that one bed.

I remember my Aunt talking about the best artichoke bed was down near the pig and cattle pens. For what it's worth and a 1949 memory.

Kay

Oh, by the way, it does look like that plant has a good dose of powdery mildew on it. But these plants are quite sturdy and it probably wont terribly effect the tubers.