Try this annual. It can be found in garden centers (not necessarily the big box store garden centres), and it is one of the bluer of the blue colours. Grows in an upright form, once it starts it doesn't stop. I grew it one year and loved it, and forgot about it since this fall, I'm going to have it again next year.

Here is a link that might be useful: Anagallis

Salvia farinacea, Victoria or Rhea. Lovely 12 to 18 inch spikes of true blue. Absolutely carefree and wonderful.

Ageratum blue horizons and larkspur....which will re seed with abandon.
Linda C

Bachelor Buttons,all the way!
Bluest of the blues,definitely bold!

Take a look at anchusa varieities (also called bugloss). You'll probably need to buy seed as this is an overlooked genus

wow that anchusa looks great! I prefer starting from seed when possible because you get the best varieties from seed.
Ah yes, and there's bachelor buttons. Let's not forget those sweeties.

Salvia Cambridge Blue has large flowers for a salvia and is a true sky blue.
Here's a photo, not the best, but it gives a good size relationship for the blooms.
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Remy

These blue pansies are usually available at most garden centers:
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How about some beautiful blue bearded Iris or Dutch Iris in a pot? Those are very "manly" type strong flowers, and they cut beautifully! Also, don't forget Rosemary! A wonderful easy care herb that blooms blue, and gives you joy at breakfast in some fried potatoes, at the barbecue with shrimp strung on it's strong stick like stems, and the list goes on. If you put it in a pot, the HOA can't say a thing!!

Campanula carpatica Blue Clips: known as bluebells sometimes. Also delphiniums! they're magnificent.

nemophilia, centaurea, linum narbonense, browallia, sweet pea - many blue shades - morning glory 'Heavenly Blue' or 'Granpa Otts', brunfelsia, salvia farinacea, jasione (sheepsbit scabious) primula capitata, BULBS, bluebells, grape hyacinth, tritilea, chionodoxa, hyacinth, babiana, various iris -reticulata, algerian, dutch, english or siberian.

Caryopteris incana has spikes of mid-true blue flowers and makes a fine annual for colder regions (it was reliably perennial for me in zone 8b).

Aside from hardiness, it differs from the commonly grown bluebeard in that the flowers completely encircle the stem in C. incana.

Himalayan Blue Poppies. They are a perennial though.

Here is a link that might be useful: {{gwi:24303}}

Nigella comes in various shades of blue and I second the comment about Sweet Peas, especially Lord Nelson, a really dark blue. Those pansies are fabulous, I'll have to keep my eye out for those this year. I like blue flowers, too. Also borage is a blue flower and edible as well. It's actually a self-seeding herb tasting of cucumber.

Salvia 'Black and Blue': hummingbirds love it.