Origin
Lewisia pygmaea (Gray) B.L. Robins. ssp. longipetala (Piper) Ferris, commonly known as dwarf bitterroot, is a mat-forming perennial herb that is native to western North America. It is found mainly in the Cascade Mountains of Oregon, Washington, and British Columbia.
Common Names
Dwarf bitterroot is commonly known as Lewisia, pygmy bitterroot, cliff maid, and bitterleaf. The name Lewisia honors Meriwether Lewis, who led the Lewis and Clark Expedition in the early 1800s and collected the first specimen of this plant.
Uses
Dwarf bitterroot has been used by native tribes in the Pacific Northwest for medicinal purposes, including treating skin ailments and digestive issues. Additionally, it is often grown as an ornamental plant due to its low-growing habit, bright-colored flowers, and attractive foliage.
General Appearance
The plant has small, fleshy, succulent-like leaves that form a basal rosette. Its flowers are typically pink, magenta, or white, and are supported by a stalk that rises just above the foliage. The flowers bloom in late spring to early summer and attract pollinators such as bees and butterflies. The plant grows to a height of 2-4 inches and spreads to form a dense mat.
Light Requirements
Lewisia pygmaea ssp. longipetala requires direct sunlight to grow. It thrives in full sunlight, and if planted in partially shaded areas, it may not be able to produce flowers.
Soil Requirements
The plant prefers well-draining soils that are rich in organic matter. The soil pH should be mildly acidic to neutral with a pH range of 5.5 to 7.5. It prefers soils with a sandy texture, but it can also grow in loamy or clay soils that are well-drained.
Temperature Requirements
Lewisias pygmaea ssp. longipetala grow best in areas that have cool summers and wet winters, such as the Pacific Northwest of North America, where it is native. It can tolerate temperatures as low as 14°F, but it prefers temperatures in the range of 25°F to 75°F.
Watering
It is important to keep the soil moist but not waterlogged. Overwatering may cause root rot, and underwatering may cause the plant to dry up and wither. Watering once a week is sufficient for the plant to grow but may need more frequent watering during hot and dry spells.
Cultivation:
Lewisia pygmaea (Gray) B.L. Robins. ssp. longipetala (Piper) Ferris can be grown in a variety of settings. It prefers well-draining soil and partial shade, making it ideal for rock gardens, containers, and raised beds.
Watering needs:
As a drought-tolerant plant, Lewisia pygmaea (Gray) B.L. Robins. ssp. longipetala (Piper) Ferris doesn't require overly frequent watering. In general, it's best to water deeply but infrequently to avoid waterlogging the roots.
Fertilization:
To promote healthy growth with Lewisia pygmaea (Gray) B.L. Robins. ssp. longipetala (Piper) Ferris, it's recommended to fertilize the plants once a year in the spring. Use a balanced fertilizer (10-10-10) that has been diluted to half its typical strength. This will provide your plant with the necessary nutrients it needs to thrive.
Pruning:
Lewisia pygmaea (Gray) B.L. Robins. ssp. longipetala (Piper) Ferris doesn't require extensive pruning, as it is naturally a compact plant. However, it's important to remove any dead or yellowing leaves regularly to promote overall plant health. If the plant becomes too large, it can be gently divided in the spring.
Propagation of Lewisia pygmaea (Gray) B.L. Robins. ssp. longipetala (Piper) Ferris
Lewisias can be propagated by division, stem cuttings, or seed.
Division
Divide your Lewisia plant every three to four years to promote growth and reduce overcrowding. Use a garden fork or spade to carefully lift the plant from the ground. Gently separate the root system into smaller sections, making sure each section has a healthy root mass. Transplant each section into a well-draining soil mix. Water thoroughly and keep the soil moist until you see new growth.
Stem Cuttings
Take stem cuttings in the spring or early summer, when growth is most active. Cut a 3- to 4-inch section of stem from the parent plant, making sure it has at least one node. Remove the leaves from the lower half of the stem. Dip the cut end in rooting hormone powder and plant it in a well-draining soil mix. Keep the soil consistently moist. The stem cutting will develop roots in about four to six weeks.
Seed
Sow Lewisia seeds in early spring, just after the last frost. Scatter the seeds over a well-draining soil mix and gently press them into the surface. Do not cover the seeds with soil, as they need light to germinate. Keep the soil consistently moist until the seeds germinate, which should take about two to four weeks. Once the seedlings have developed their true leaves, transplant them into individual pots. Grow them under bright, indirect light and keep the soil consistently moist.
Disease Management
Lewisia pygmaea (Gray) B.L. Robins. ssp. longipetala (Piper) Ferris is susceptible to a few diseases. The most common disease that affects this plant is fungal disease.
One of the common fungal diseases that infect Lewisia pygmaea is powdery mildew. It appears as a white growth on leaves, stems, and flowers. Severe infections can cause the plant to lose its leaves. To manage powdery mildew, remove infected leaves and flowers as soon as possible. Avoid overhead irrigation and allow enough space between plants for good air circulation. Using fungicides can also help manage the disease.
Leaf spot is another fungal disease that might affect Lewisia pygmaea. This disease appears as circular, water-soaked spots on the leaves. Over time, the spots turn brown and may develop a yellow halo. Leaf spot can weaken the plant, and severe infections can lead to defoliation. To manage leaf spot, remove infected leaves and sterilize pruning tools before using them on healthy plants. Proper irrigation and good soil drainage can also help manage the disease.
Pest Management
Lewisia pygmaea is not prone to pest infestation, but some pests might attack the plant.
Aphids are small, soft-bodied insects that suck the sap of the plant. They usually appear in large numbers and cause the plant to weaken and develop yellow leaves. To manage aphids, use a strong blast of water to knock them off the plant or spray insecticidal soap or neem oil on the affected plant.
Spider mites are tiny pests that usually appear in warm and dry conditions. They suck the sap of the plant and cause the leaves to appear stippled with yellow or white spots. Severe infestations can lead to defoliation. To manage spider mites, use a strong blast of water to dislodge them from the plant or spray the plant with insecticidal soap or neem oil. Also, maintain good air circulation around the plant and avoid over-fertilizing, which can attract spider mites.
Snails and slugs can also pose a threat to Lewisia pygmaea. They usually feed on the leaves of the plant, leaving irregular holes. To manage these pests, handpick them off the plant or use traps like beer traps. Additionally, remove debris around the plant where they might hide.
