As part of the Boragineae tribe of the Boraginaceae family, the anchusa plant genus includes about 40 individual species. Although different anchusa species are classified as annuals, biennials, or perennials, bright blue flowers are the common feature. The trumpet-shaped flowers are small and feature five sepals and five petals surrounding a thin, inner tube. Anchusa plants are classified as herbs and feature hairy stems with bright green leaves.
The height difference from one type of anchusa to the next can add variety to home garden designs. Smaller plants can fill in gaps, while taller ones are often used to create borders. Seeds should be planted just below the soil's surface and spaced 10 to 30 inches (25 to 75 cm) apart depending on their size. Germination occurs in one to four weeks on average. Annuals are planted in early spring in full sunlight, while perennials are planted after all danger of frost is past and tolerate either shady or sunny conditions.
Anchusa capensis, also known as bugloss, blue angel, and forget-me-not, produces bushy clusters of small, bright-blue flowers. The forget-me-not has a five-petal flower configuration that is less tubular than many other varieties. This perennial's blooming period is both early and long lasting. It grows to a height of 12 to 15 inches (about 30 to 38 cm) and spreads 12 to 15 inches (about 30 to 38 cm) wide making it a popular choice for both borders and flower beds.
Loddon royalist, or Anchusa azurea, is a perennial that grows to 3 feet (almost 1 meter) tall. In late spring or early summer, the tall spikes produce a deep-blue bloom that is slightly larger than the smaller forget-me-not. As the plant grows taller, it requires support to prevent breakage. The loddon royalist can self-seed in excellent growing conditions, but is usually propagated with cuttings. Unsightly foliage frequently requires cutting back after the blooms have dropped.
Anchusa officinalis, also known as common bugloss or alkanet, is classified as a biennial or perennial herb. It grows up to 3 feet (almost 1 meter) high and blooms from late spring to early fall. The flowers vary from bright blue to purple but it isn't a welcomed plant in most areas. In 46 U.S. states, it is considered an invasive or noxious weed. Handling of this anchusa can cause skin irritation or an allergic reaction.