Blue is one of the least common colors found in spring flowers, so a garden full of blue blooms in March or April can stand out on the block as unique. Sadly, most popular blue popular flowers don't begin to bloom until early summer. There are a few great spring plants with blue flowers, however, if you want to deck your garden with shades of cool, soothing hues.
More commonly known as forget-me-nots, these are traditionally used in beds. Sow the seeds in autumn, or start them indoors to get a jumpstart on the season. The flowers bloom in early April in most regions, but only last a couple of months. Trim off the flowers as they begin to wither to help prolong the growing season.
Primroses are another popular bedding flower that come in a variety of shades, including blue. In full sun in mid-zones they'll flower in early March, but should be given shade as the weather warms up. They will bloom until summer. Give them a soil that is slightly acidic for best results.
Ajuga, or bugle plants, are hardy perennials that will begin flowering in May and will continue to produce short spikes of blue flowers through the summer. Since ajuga is low growing, only reaching 4 to 6 inches, it makes a good edging plant. Keep it protected from the worst heat of the day and it will ask for little else. Ajuga adapts to the conditions you provide.
Commonly called columbine, blue is one of the many shades of hese hardy perennials. They'll bloom at least throughout May and June in the USDA Zones 3 through 9; but if you start them early in warmer climates you might get an extra few weeks. Provide them with partial shade.
With its speckled leaves, pulmonaria, or lungwort, makes quite a display in cottage gardens. Pulmonaria sports tubular flower in various shades, including blue. They are not fussy about soil, but they insist on shade.
Periwinkle, as it is commonly known, has its own shade of blue named after it. Though technically a shrub, it is compact, growing only up to 12 inches high, and it will show off sprays of small blue flowers from mid-spring until mid-fall. Periwinkle is a low-maintenance plant; it tolerates sun or shade, is not picky about its soil and it tolerates heat and droughts well.