Mystic Spires blooms until frost, they are just starting to flower now. Gorgeous next to New Gold lantana. Both bloom simultaneously all summer. The mystic spires blooms better with some moisture but might not return if it's too moist over the winter.

I have five different varieties (colors) of greggi and like them all. The light pink shows up the best - the light color and larger bloom.
They have different names but all do about the same though some have bigger blooms and habit.

I planted several indigo spires this year and predict it will be similar only bigger, of course, than Mystic. Will see.

Victoria Blue farinacea blooms until frost and is very attractive in it's dried state all winter. The others are not. It's a favorite.
May Night for all it's popularity, has been a dud in my yard. I have planted probably 2 dozen over the years but no more.

Blue Hill is the hardiest and rock solid. I have one ten years old, dug and moved twice and in its original, highly neglected spot, it has come back and bloomed each year.
No water, fertilizer, little mulch in that spot. Given some care, it's lovely.

It has a major flush that lasts a long time then I shear it back and it reblooms.

Cardoona, pretty nice if I keep it sheared after the spring flush. Much hardier that May Night.

I love salvias. They a mainstay in my garden after roses.
The greggi's are so easy to break off a rooted piece and plant.

I have black and blue too but it's not a favorite- too much foliage for small flowers. But I still have several and they don't require anything but sun. The blue is beautiful though.

I stopped planting pineapple as it had such a short bloom time and rarely overwintered. Too much work.

Thanks bumblebeez, that is very helpful. I also like that lantana/salvia combo. Good recommendation!
I do have several greggi, and some black and blue and "purple" (mine looks blue)...and hopefully some azure colored in the same family(I'm hoping a neighbor lets me have some of his. The color makes up for the smaller blooms - the lighter blue is more noticable).
I am looking more for those such as Mystic Spires and especially your description of Blue Hill because it won't get extra water often in the front yard. They get well mulched, tended...but not so much water because I took out the poorly functioning soaker hoses. Hopefully next year we can get a rain pillow and drip irrigation out there.
I have several blue salvias, they all tend to bloom early and not again which is very disappointing. I need that blue!

If you need blue, do you have Stokesia laevis (Stoke's Aster)? The cultivar 'Peachie's Pick' has a very long bloom season, I thought. I have it.

Esh, I did buy a Peachie's Pick but I don't think it really is. Not a very long season of bloom for me, and I need vertical more than anything. I like the salvia spikes. I can take care of the job with some annuals this year (don't have to be blue) but I would like to add more of the "spike" salvias in future years.

The late summer blooming blue Lobelias are nice: Lobelia puberula and Lobelia siphilitica.

Esh, I've tried lobelia siphilitaca a mission times and I get it germinated, growing, transplanted...and by mid summer it's just to dry in my front I guess. Lobelia puberula, does that need super acid soil? The photos I just saw look like piney woods. Which I don't have.
I can't wait for the day we can get a rain pillow and drip irrigation...some day....

While not true blue, angelica will bloom until frost and is fairly attractive, if an annual.

We find Lobelia puberula in this area, but I am not sure about the Ph. It seems to tolerant a wide variety of conditions, including moist areas and meadows (which I think of as dry usually).

Here is a link that might be useful: Might be available here