What type of sweet pea is best for my climate?
The Spencersweet peas are my favorite sweet peas. Why? The variety of colors is unmatched - spectacular colors with all of their subtle variations. The size of the blooms, and the ruffling of the blooms is unmatched by the other types of sweet peas. Based on feedback from customers, the Spencers do well in the Pacific Northwest, on the Californis coast, in Alaska, and in New England. I haven't heard from gardeners in the upper midwest, but they may be okay for this area in years that you get a cool summer.
The Old Fashioned Types, are my second favorite types. They have bright, cheerful flowers and very strong scent. Although all sweet peas are cool weather annuals, the Old Fashioned types hold up better than the others in the heat. So these types can be tried anywhere. If you are in the south or in the arid west, plant them in the Fall. Otherwise early spring plantings, started in small pots for later transplanting in April (or thereabout) is your best bet.
The Winter Elegance Types were bred specifically for the USA hot summer climates. Does this mean they tolerate the Heat? No, it does not. What makes the Winter Elegance types suitable for many of our climates is that they beat the heat. Specifically, they start blooming early and finish blooming early before the heat really gets going. Usually they are planted in the Fall. These work well in the south and the arid west.
The Royal Family types were also bred in the USA for our hot summer climates. The blooms are large and go well with the Old Fashioned types. Try these anywhere.
The Dwarf types. I have no specific information on climate requirements for the dwarf varieties. Try them anywhere.