Viscaria flowers will generally start as small, grass-like tufts of foliage, eventually reaching about 5 inches in height before producing flowering stalks. Viscaria is also called sticky catchfly, clammy campion, and rose of heaven. Its “sticky” nickname comes from its gummy, viscous substance that catches bugs nosing around. The stalks can rise as high as 12 to 18 inches tall. Viscaria plants are usually stiff enough to hold their own weight, but if you plant one of the taller varieties of viscaria, you may need to provide stakes or other forms of support. Consider viscaria plants as a way to add a colorful border to a rock garden or any other dry areas. The viscaria flower contains brassinosteroids, a substance used in plant strengthening formulas and fertilizers. They can help to promote disease resistance and the overall health of any flowers planted nearby. However, they are susceptible to slugs and snails, which can damage foliage.
Light
The viscaria will thrive in both full sun and partial shade. However, they should ideally receive full sun for at least half of the day. Though they can tolerate partial shade, bright sunlight will help bring out the plant’s vibrant colors and promote stem strength.
Water
Viscaria plant is undemanding and somewhat drought-resistant, but don’t let your plants become too dry. Water either in the morning or evening, as opposed to the midday, particularly on sunny days. Plus, don’t let the soil become waterlogged; it might cause root rot and kill the plant.
Soil
Viscaria can grow when planted in a wide range of soils. However, steer clear of heavy, wet soil. Well-drained soil is best, and they will thrive in slightly sandy, loamy soil.
Temperature and Humidity
These are hardy plants that can tolerate a bit of frost. Some varieties of viscaria can survive freezing temperatures. It’s generally best to plant these plants after the coldest part of the winter has passed.
Fertilizer
Viscaria plant doesn’t require fertilizer, but it can help promote healthy growth. Liquid fertilizer can be used during the summer. However, for best results, apply monthly throughout the warmer months.
Viscaria Varieties
Several subspecies often get confused for varieties or cultivars for Silene viscaria. The most common cultivar, ‘Splendens Plena,’ features bright pinkish magenta double flowers. It is also sometimes sold as ‘Splendens Flore Pleno’ or ‘Flore Pleno’.
Pruning
Viscaria plants don’t require extensive pruning; however, you can deadhead spent flowers to encourage fuller blooms. Trim inflorescences or flowering stalks to about two inches, and prune stems and branches after the flowers have bloomed. Time your pruning to before the seeds have matured, so the plant puts its energy toward its flowers instead of forming seeds.
Propagating Viscaria
Viscaria plants can be propagated in a few different ways: seed, offsets, or division. Viscaria plants that are rooted outdoors should freely self-seed. The best time to start sowing seeds is between February and May. They will take about two weeks to germinate (in temperatures between 64 and 68 degrees Fahrenheit). Once the plant begins to produce its grass-like tufts, you can transplant them to garden beds or plant containers.
Potting and Repotting Viscaria
When planting viscaria in containers, it’s important to sow only a few seeds per pot (and thin the seedlings to just one plant per pot). Transplant potted plants every couple of years to fully replace the soil and provide a larger pot for the root system.
Overwintering
Viscaria is native to the cold tundra of Siberia and is hardy down to -25 degrees Fahrenheit. If you are planning to overwinter viscaria outdoors in containers in extreme frigid temps, those plants will need winter protection, such as placing them on wooden blocks and wrapping them in fleece.
