Great article! It really is a wonderful food to grow.
Here (zone 8a) chard will grow year-round. The leaves can wilt in summer heat, but perk right back up at nighttime or on an overcast day. A hard frost will damage some exposed parts but again, it comes right back once the weather warms up. I've grown it in containers and in the ground, in full sun and nearly-full shade, and it just keeps on truckin'. I recommend it to all my novice gardener friends who want to grow their own food but don't know where to start.
I always grow Bright Lights because the color is fun, but I've actually had better luck with a variety called Perpetual. It tolerates both cold and heat a bit better than the Bright Lights, has larger leaves, and is slower to bolt. I find it to be a bit less strongly flavored as well. The only downside is that it looks rather plain compared to all the colorful options out there.
