Germander Speedwell (Veronica chamaedrys) offers delicate blue flowers set against bright green foliage. These blooms grow in the wild throughout much of Europe but can be cultivated for formal gardens, too. The flowers prefer moist but well-draining soil and thrive in full sun or partial shade. Bonus? Bees and other pollinators love them. Note that these flowers may be invasive in certain areas, so be sure to check before planting. Germander Speedwell is typically hardy in Zones 3 – 7.