Ok, that's great to know. A month or two ago I read this (<--click me) article written by a gardener in New Jersey (admittedly south of us, but probably also zone 6) suggesting that the Pacific Giants and the Blackmore and Langdon hybrids wouldn't do well there. But maybe there are just so many unknown variables that affect whether any particular plant will grow in any given place, and there's no reason not to give them a try.

Maybe part-sun is the secret. You give them morning sun?

Years ago I had a gardening friend who grew the New Millennium delphiniums. It was a major production to find the seeds, pay for the seeds, then grow the seeds, but she thought it was worth it. I've done OK with Pacific Giants, and very well with some of the smaller species delphiniums, so wasn't all that interested at the time.

The best delphiniums I've seen were in coastal Maine, and southern Nova Scotia, so not that far from you. New Jersey summers are a different beast, and I wouldn't say that was particularly relevant. If you have a local garden center that sells small, cheap seed grown plants, just get a few varieties of what they carry, and see how they do.

My delphiniums are in part shade or dappled shade in the afternoon, but they do get full sun in the morning. And the soil around them is protected from drying out by mulching and by planting shorter perennials around their base to keep them cool. I agree with gallica, you can always try a few inexpensive seeds and see how they do in your garden.

I did what mad_gallica's friend did - a major production to find the seeds etc, but I also thought it was totally worth it. I grew them for a couple of years, they didn't continue to keep coming back and I changed gears and wanted to put less time into flowers and seed starting that were not perennials. I'd definitely try the New Millennium Delphiniums again. Sometimes someone starts seedlings of them and I'd rather buy them that way and not go to the trouble of starting them from seed. I bought mine directly from New Zealand I think and they were expensive, but I did end up with some quality plants.

Here is one photo of them that I could put my hands on easily - these were growing up against the back of the house in half day sun facing West, so not a full day of sun.

I have been successful buying small plants of the low growing, single-flowered Butterfly Blue. They are relatively short-lived, but are a gorgeous bright blue that blooms all summer into fall.

Many years ago (so long ago that I don’t remember the variety) I grew from seed one of the taller, double types, but after a couple of seasons of ugly mildewed foliage I ripped them out.

A few years ago I heard good comments on D. elatum on the perennial forum, so that is one I am planning to grow from seed. I think the flowers are single and typically bright blue.

I have Delphinium grandiflorum ‘Blue Butterfly’ indoors under grow lights right now and have a couple of seedlings already.

Babs - The reason I went to the trouble of getting the Dodswell seed is they were bred for mildew resistance etc. Here's an article on it....and I don't remember having any problem with them.

Breeder Profile Terry Dowdswell - Walter's Gardens