Mertensia is a flowering plant genus native to North America and found primarily in temperate to cool regions. Members of this genus are sometimes known as bluebells, a common name shared with several other plant genera as well. Several species are cultivated as ornamentals and many others can be spotted on wildflower walks throughout the native range of this genus. It is estimated that around 40 species fall under the Mertensia genus.
These members of the borage family have an herbaceous growth habit and are perennial. The leaves and simple and alternate, produced on low plants with minimal branching. Clusters of pink buds form in the spring and develop into blue, bell-shaped flowers. In the fall and winter, Mertensia species die back during the cold weather. They will return with new growth in the spring and often propagate underground with the use of rhizomes, expanding their growth each year.
Gardeners in United States Department of Agriculture (USDA) zones three through eight can cultivate Mertensia species in their gardens. They will need full to partial shade, as these plants are adapted to woodland environments, and the soil should be rich, worked with leaf litter, and well-drained to prevent rot and other damage to the roots. Seedlings can be established in spring and if the plants like the area where they are planted, they should continue to grow. Gardeners can also obtain divisions from people with existing stocks of the plant and use them to start a patch of Mertensia.
Members of this genus do best in massed and clumped plantings. They will tend to sprawl over time as a result of their self-propagating tendencies and they can become invasive in some gardens. Gardeners displeased with the bare patches that appear when the plants die back can pair Mertensia with a groundcover to keep the garden looking neat and tidy when bluebells are not present. Low-lying herbaceous groundcovers will also help keep weeds out of the garden, reducing the amount of time people need to spend weeding.
Although many species can be found in the wild, it is not advisable to use wild plants to establish stock in the garden. This can disrupt wild populations, including populations of threatened plants or plants playing an important role in a local ecosystem. Nurseries, garden supply catalogs, and other gardeners should be able to provide people with a source for Mertensia to use in their gardens without needing to disturb wild plants.