Origin
Lewisia cotyledon (S. Wats.) B.L. Robins. var. howellii (S. Wats.) Jepson, also known as Howell's lewisia, is a succulent plant species that is endemic to western North America. It is mostly found in the Oregon and California states of the United States.
Common Names
The plant is commonly known as Howell's lewisia, Siskiyou lewisia, and cliff maids.
Uses
The plant is primarily grown for ornamental purposes due to its attractive, showy, and vibrant flowers. It is a popular choice for rock gardens, alpines, containers, and borders. The plant does not have any significant medicinal uses but it is sometimes used in traditional Native American medicine to treat diarrhea and as an emetic.
General Appearance
Lewisia cotyledon (S. Wats.) B.L. Robins. var. howellii (S. Wats.) Jepson is a small, evergreen, and fleshy plant that grows up to six inches in height and twelve inches in width. The plant has a basal rosette of succulent leaves that are densely clustered and often form a rosette. The leaves are long, narrow, and up to four inches in length. The plant produces an erect floral stem that bears a terminal cluster of four to twelve flowers that open wide and have five petals with varying colors including pink, purple, red, or white. The plant typically blooms from late spring to early summer.
Light Requirements
Lewisia cotyledon var. howellii prefers full sunlight to light shade. It can grow well in areas that receive direct sunlight for at least six hours a day. In areas with hot, intense sunlight, shading may be necessary to prevent the plant from drying out quickly.
Temperature Requirements
This plant is native to the rocky mountain regions of North America and is adapted to a range of temperatures. It can tolerate cold temperatures, withstanding temperatures as low as -20°C (-4°F) in winter. However, during summer, temperatures should not exceed 30°C (86°F), as this may cause damage.
Soil Requirements
Lewisia cotyledon var. howellii requires a well-draining, rocky or sandy soil that is slightly acidic. A pH range of 5.5-6.5 is ideal. It can suffer from root rot if the soil is too heavy and holds too much moisture. Soil fertility is not as important, and the plant can grow in poor soil conditions, provided the drainage is good. Compost can be added to the soil during planting to improve soil structure and nutrient content.
Cultivation Methods
Lewisia cotyledon var. howellii is a perennial plant that prefers well-draining soil and full sun exposure. When choosing a location to grow these plants, consider both of these factors as they will play a significant role in the plant's health and growth. Ensure that the soil is sandy and slightly acidic, and if necessary, amend it with some coarse sand or gravel to improve drainage. Plant the Lewisia cotyledon var. howellii in the spring after the last frost, and space the plants at least two feet apart to encourage healthy growth.
Watering Needs
Although Lewisia cotyledon var. howellii prefers well-draining soil, it still requires regular watering, especially during the dry months. Be careful not to water them too much, as this can cause root rot, which can be fatal to the plant. Generally, water the plant about once a week, but if you are experiencing a prolonged dry spell, water more frequently. Ensure that the soil is moist but not waterlogged.
Fertilization
When it comes to fertilization, Lewisia cotyledon var. howellii is not too demanding. You can use a well-balanced, organic fertilizer in small quantities once or twice during the growing season. Be careful not to over-fertilize the plant, as this can lead to excessive vegetative growth and reduced flowering.
Pruning
Pruning of Lewisia cotyledon var. howellii is required to remove any dead or damaged foliage and encourage new growth. You can prune the plant in the early spring or fall after flowering, taking care to avoid cutting off the flower buds. Pinch or snip off the spent flowers, as this can encourage the plant to produce new blooms. Always use a sharp and clean pair of pruning shears to prevent the spread of diseases.
Propagation Methods
Lewisia cotyledon (S. Wats.) B.L. Robins. var. howellii (S. Wats.) Jepson, commonly known as Howell's Lewisia, can be propagated through seed, leaf cuttings, or division.
Seed Propagation
Seeds can be sown in a well-draining potting mix during early spring or late summer. Before sowing, seeds should be stratified at 2-5°C for 2-4 weeks to mimic winter conditions. Sow seeds at a depth of 1/8 inch, and keep the soil moist. Germination may take up to 3 weeks. Once the seedlings have developed true leaves, they can be transplanted into individual pots or directly into the garden bed.
Leaf Cutting Propagation
Lewisias can also be propagated from leaf cuttings. Cut a healthy leaf, avoiding any damaged areas, and make a clean cut at the base of the leaf. Insert the leaf cutting into a well-draining potting mix, burying the stem to half its length. Water the cutting and place it in a shaded area. Keep the soil moist and wait for roots to develop, which may take a few weeks. Once the roots have developed, the new plant can be potted up or planted directly into the garden bed.
Division Propagation
Finally, Lewisia cotyledon (S. Wats.) B.L. Robins. var. howellii (S. Wats.) Jepson can be propagated through division. In early spring, dig up an established plant and carefully separate the root system into sections. Each section should have a portion of roots and several healthy shoots. Replant the divided sections into individual pots or directly into the garden bed.
Disease and Pest Management for Lewisia cotyledon var. howellii
Like any other plant species, Lewisia cotyledon var. howellii is susceptible to several diseases and pests that can cause devastating damages to the plant's health and growth. However, understanding the common diseases and pests that can affect the plant and implementing proper management practices can help minimize the risk of infestations.
Common Diseases
One of the most common diseases that affect Lewisia cotyledon var. howellii is powdery mildew. Powdery mildew is a fungal disease that manifests as white powdery spots on the plant's leaves, flowers, and stem. Infected plant parts might die if the disease is left untreated. Other common diseases include damping-off, leaf spot, and Botrytis blight.
Pest Management
Lewisia cotyledon var. howellii is seldom attacked by pests. But when pests like spider mites, slugs, and snails feed on the plants, they can cause significant damages to the plant's foliage, flowers, and fruits. The following are ways to manage pests on Lewisia cotyledon var. howellii:
- Handpick snails and slugs or use beer traps to trap and kill them.
- Using a direct stream of water, carefully wash spider mites and aphids off the plant's foliage.
- Encourage beneficial insects that feed on pests to inhabit the garden. Examples include ladybugs, lacewings, and parasitic wasps.
Disease Management
To prevent diseases from attacking Lewisia cotyledon var. howellii, it is essential to avoid wetting the plant's foliage and stem during watering. Additionally, the following management practices can help minimize the risk of plant diseases:
- Plant disease-resistant cultivars.
- Practice crop rotation to prevent the buildup of disease-causing pathogens in the soil.
- Destroy or remove infected plant parts, including fallen leaves and stems, to prevent the spread of diseases.
- Disinfect garden tools before and after use to prevent the spread of diseases from one plant to another.
In conclusion, proper disease and pest management practices are essential to keep Lewisia cotyledon var. howellii healthy and productive. By identifying and managing pests and diseases early, gardeners can prevent the spread of pathogens and minimize the risk of plant destruction.
