Update on my swiss chard...as I mentioned above, I suspected frost damage one day when I noticed circular tan spots. The spots spread for days and the leaves are now schriveled up and brown/black...they are toast. Was the cause frost?
I'm with rainbowgardener on this one. Swiss chard is pretty tough. Some even winter over here in zone 8 Wa. If they were tender transplants, maybe. I would be looking for another cause. Dease, insect, something wrong with the soil. Unfinshed compost
I have sometimes had Swiss chard over winter and start growing again in the spring here in zone 6b, if we have a milder winter!
Sounds like it got diseased, although really Swiss chard is usually resistant to most diseases too. I love growing it because it is (for me) the easiest thing in the garden to grow. So I'm kind of at a loss for what happened to yours.... sorry; I know it is frustrating.
I have that problem with zucchini, everyone talks about how easy zucchini is and watch out you will have zucchini coming out your ears. But for me it always gets root borers and dies...
Unless it was a very hard frost, I doubt the frost was the cause. It sounds like disease, but as RG said, it's not too common for the chard to get disease.
I think that DDF may be onto something when he asked if you used any unfinished compost. What happens is as the bacteria are finishing your unfinished compost, they "gas-off" in the soil and that can harm your plants at the root-level.
Actually, the Scotts product is pretty good. I don't use it, but it is a pretty good soil base for a garden. They use the word "manure" on the label causing people to think it really has some nutritive value. I think they may put a table spoon of manure with the organics which they call humis. The way most companies add manure to their "manure" products makes me think they must have a bunch of constipated cows.