It should do OK in zone 6B, but it will likely be dormant 5 to 6 months of the year. It will go dormant at first frost and will not green up until your weather is up around 80 and higher. FWIW Zoysia does not look anything like Saint Augustine. It looks more like Bermuda just not as fine textured or as green as Bermuda. If you go with Zoysia I suggest Meyers aka Z52 because it has the best cold tolerance of the Zoysia varieties.

My Dream Come True roses are in this vivid knock-your-socks-off color combinations, and they do fine for me in zone 5. As for the rating systems, most hybrid teas are "officially" rated as zone 7 as a default, and some of them will immediately croak in any colder zone. Others are really perfectly fine in zones 6 or 5, as long as you bury the graft below the soil so the rose can come back if it needs to be pruned back to the soil line. You don't necessarily know about a rose until you see gardeners in your zone or your area talk about a particular rose. It's also good to know if the rose is robust or just barely surviving in a given zone - I have a 7 year old Love and Peace, but it's about 2 feet high and maybe puts out 2 blooms on a spindly plant per year. Bella Roma was iffy for me last time I planted it, but has seemed to come back this past winter. Here's a shot of Dream Come True, and while she dies to the ground in our winters she's pretty robust at growing back to 4' or so and blooming well. This one is about 5 years old. Cynthia

I've been wanting to try some more cold hardy cacti outside all year, too. I've had the same doubts about the claimed cold hardiness I've seen on the Internet. Some of the cold hardiness ratings I see listed by some nurseries seem a bit exaggerated to me. However, I'd rather not point fingers at any specific nurseries because I have no hard evidence to the contrary. Plus cold hardiness is not the only thing needed for a cactus to survive the winter. As I mentioned, they do better in the extreme cold if they are dry. Perhaps those cold hardiness ratings I have doubts about are possible if the plant is completely dry. I'm in the Snake River Valley, Idaho. I'm not sure how the precipitation here compares to that of New England. I don't cover my cactus bed. It does get wet and frozen during the winter. So far I've had good luck with certain kinds of Pediocactus simpsonii and Escobaria missouriensis. I have a couple small Escobaria sneedii or leei (the label says leei but the growth habit suggests sneedii) that over wintered OK last winter, too. Also, there are some wild kinds of Opuntia that grow in the valley and mountains.

You will be more likely to get feedback if you put the photos directly in the thread and give us some info on the amount of sun each area gets and at what time of day such as all afternoon or midday only for 4 hours. Also, can you give us a general part of the country such nearest big city? Zone 6 in NM is pretty different from z 6 in Illinois or in MA. Good ideas with moving mulch from tree trunks, getting rid of the landscape fabric, and avoiding invasives and aggressively spreading plants!