I grow Arum too, but they come up in the fall, stand all winter, bloom in the spring and then go dormant until fall when you see their seed stalks. Great plant, but not a great substitute for caladiums. I am not certain that it is winter hardy, but Calla bulbs might be a suitable substitute for caladiums in your area and would enjoy similar growing conditions. The white calla called "Crowborough" is supposed to be the most winter hardy type. I saw it offered by Arrowhead Alpines. You have only two choices: pick another plant or dig your caladium bulbs each year (#3 buy new caladium bulbs each year) :)

I am in zone 6 in southern Ohio. It is hot but you can still start peas. I planted mine in seed starter cells on my deck and kept them well watered (be careful though because too much water will rot them) so the soil temp wasn't too hot. They grew just fine and I transplanted them in my garden last week. They are still doing well. Along with peas I have broccoli growing on my deck in seed cells. I kept them in the shade but as soon as they started sprouting moved them to a sunny spot (they will get leggy fast if you don't). You could always pre-sprout seeds in a damp paper towel in the house if you are worried about the temperatures. I will plant lettuce and spinach but not yet, it is still too hot. Btw, I live in zone 6a, close to areas in zone 6b.

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.

I've had Sabal minor (Mccurtain and simply an Arkansas selection) at my (zone 6b/7a) houses for 23 years now. I've had defoliation a few times when the wind dried them out after ground froze (would recommend somewhere protected from prevailing winds), but in both houses (Oklahoma and now Arkansas), they have experienced up to -27F (polar vortex event) and passed through the other side. In both houses, maturity (ie berries) were produced. I have a mature Arkansas one now and a small McCurtain seedling (4 years or so now). It should produce a mature leaf (upright and divided) this year. I would say that to reach the flowering stage took about six years (though I don't remember if that included a setback winter) in both places. We had a -17 last year, but it didn't really hurt it, but a year before that we had drying winds with frozen conditions...not that cold but blistering, killing essentially all the foliage. I took this photo two days ago. I provide no protection at all other than initial siting of the plant. I think they should be more used in landscapes. We have few evergreens native to my state at least. Oh, and I had a needle palm in Oklahoma and while I've been considering it, I am not currently growing one, and probably won't. It grew slower (took 4 years to really begin growing) and was initially more sensitive to winter damage, though more resistant when it got older. And yes, the spines were treacherous and seemed to be mostly invisible till impaled.