What is Arenaria?

Arenaria is a genus of herbaceous flowering plants also known as sandworts. The sandworts are found widely distributed throughout the world and they are deliberately cultivated as ornamental plants in some regions. This genus is a member of the carnation family, Caryophyllales, and sandwort flowers superficially resemble those seen on carnations, also known as pinks. These plants lack the spicy odor people may associate with carnation flowers.

Members of this genus are usually small upright to trailing plants. Arenaria has blade-shaped leaves and is typically evergreen, producing small white flowers with five petals on upright flower stalks. Many species are very hardy, with their typical range being in climates similar to those found in United States Department of Agriculture zones four through eight.

Some sandworts are abundantly common. Others are threatened or endangered and there are concerns about their survival in the wild. Threatened species are typically of concern as a result of human activities in their habitat. Sandworts favor marshes, sand dunes, and other environments with sandy to loamy soil. When these areas are used by people, small plants can be trampled and may find it difficult to survive.

People interested in cultivating Arenaria can find it at nurseries and garden supplies, through catalogs, and in plant exchanges. These plants are somewhat unusual ornamentals in some regions of the world, and it may be difficult to obtain specimens for a garden. One thing to be aware of is that some species can become invasive in climates they enjoy. Gardeners may want to see if a native species is available, and if they are growing a non-native Arenaria species, it is a good idea to grow in containers or areas with clear boundaries to limit the plant's spread.

These plants require well-drained soil with the capacity for a high moisture content. They do not like to be wet, but they do need to be kept consistently damp. Sandworts benefit from fertilizer in the spring and can be propagated through seeds or division. They are excellent as groundcovers in the garden and can also be grown as container plants. The trailing species can make unusual and visually interesting features in hanging containers.

If gardeners identify this plant in the wild, they should exercise caution about collection. Some species have low numbers in the wild and are not stable enough to support plant collectors. A botanist can provide more information about which native Arenaria species can be collected.