Origin
Mertensia oblongifolia var. amoena is a species of flowering plant native to North America. It can be found across the western United States, from Alaska to New Mexico.
Common Names
This plant is commonly known as Rocky Mountain bluebells, mountain bluebells, or streambank bluebells.
Uses
Mertensia oblongifolia var. amoena is a popular ornamental plant, often used in gardens for its beautiful blue flowers. In addition to its aesthetic qualities, this plant has also been used for medicinal purposes by various Native American tribes. Some tribes used the leaves and stems to make poultices for treating external injuries, while others used it as a remedy for respiratory issues.
General Appearance
This plant is part of the Boraginaceae family and typically grows to be 10-40cm tall. The leaves are oblong or lance-shaped and are often covered in fine hairs. The flowers are funnel-shaped and range in color from pale blue to deep blue-purple. They typically bloom from May to July and attract a variety of pollinators, including bees and butterflies. After flowering, the plant produces small, dry, and papery fruits.
Growth Conditions for Mertensia oblongifolia (Nutt.) G. Don var. amoena (A. Nels.) L.O. Williams
Light: Mertensia oblongifolia var. amoena grows well in partial shade to full sun. It can tolerate full sun in cooler areas, but in hotter regions, it will need some protection from afternoon sun. In general, it prefers bright, indirect light.
Temperature: This plant is native to cool, mountainous regions and does well in cooler temperatures. It can tolerate a wide range of temperatures, from 50°F to 85°F (10°C to 29°C), but it prefers temperatures in the range of 60°F to 70°F (15.5°C to 21°C). In summer, it may need some extra watering or protection from high temperatures, especially if grown in full sun.
Soil: Mertensia oblongifolia var. amoena prefers well-draining, sandy loam soil with a pH range of 5.5 to 7.5. It grows best in soils that are rich in organic matter and have good water retention capacity. The soil should be kept moist but not waterlogged. It can tolerate some drought, but prolonged periods of dryness can cause the plant to wilt and suffer.
Fertilizer: This plant does not require much fertilizer. However, if you choose to fertilize, use a balanced, slow-release fertilizer that is low in nitrogen. Too much nitrogen can cause the plant to grow too quickly, making it more susceptible to pests and diseases.
Cultivation methods
Mertensia oblongifolia var. amoena is a hardy herbaceous plant that grows well in most soil types, although it prefers well-drained soil. It can be grown in full sun to partial shade and in USDA hardiness zones 3 to 7. When planting, ensure that the plant has enough room to spread out, as it can grow up to 16 inches tall and 12 inches wide. Seeds should be sown in the spring or fall to allow for natural stratification during the winter months.
Watering needs
Mertensia oblongifolia var. amoena prefers to be in moist soil and will need regular watering during the summer months. However, be careful not to overwater the plant as it can cause root rot. Allow the soil to dry out slightly before watering again. In the winter, the plant can handle periods of drought, but it's best to check the soil's moisture level regularly and provide water as needed.
Fertilization
Mertensia oblongifolia var. amoena is not a heavy feeder and does not require frequent fertilization. In fact, too much fertilizer can cause the plant's leaves to become droopy and yellow. Apply a balanced fertilizer, such as a 10-10-10, once in the spring or early summer when growth begins. Alternatively, you can mix in some organic matter, such as compost or well-rotted manure, into the soil when planting to provide the plant with some nutrients.
Pruning
Mertensia oblongifolia var. amoena does not require regular pruning, but deadheading can encourage the plant to bloom more profusely. Cut back the spent flowers to just above the next set of leaves to promote new growth. If the plant becomes too large and unruly, cut it back by half in the late summer or fall. This will help keep the plant's size in check and promote healthier growth next season.
Propagation methods for Mertensia oblongifolia (Nutt.) G. Don var. amoena (A. Nels.) L.O. Williams
There are a few different methods to propagate Mertensia oblongifolia (Nutt.) G. Don var. amoena (A. Nels.) L.O. Williams, including seed propagation, division, and stem cuttings.
Seed propagation
Seed propagation is one of the most common ways to propagate Mertensia oblongifolia (Nutt.) G. Don var. amoena (A. Nels.) L.O. Williams. Seeds can be harvested from mature plants and sown in the spring. Seeds should be sown in well-draining soil and covered with a thin layer of soil. Keep the soil moist and the temperature around 60-70°F until germination, which usually takes 1-2 weeks.
Division
Another method of propagation is division. To do this, mature plants are lifted from the ground and the roots are carefully separated into smaller sections. Each section should have a good amount of roots and several healthy shoots. These sections can then be replanted in well-draining soil and watered thoroughly.
Stem cuttings
Stem cuttings can also be used to propagate Mertensia oblongifolia (Nutt.) G. Don var. amoena (A. Nels.) L.O. Williams. Cuttings should be taken from new growth, about 4-6 inches long. Remove the lower leaves and plant the cutting in well-draining soil. Keep the soil moist and the cutting in a warm location with indirect light until roots begin to develop, which usually takes 2-3 weeks.
Disease Management
Mertensia oblongifolia var. amoena is relatively resistant to common plant diseases. However, it may occasionally suffer from fungal infections, such as leaf spot caused by Septoria mertensiae. The disease manifests as small brown spots on the leaves, which may merge to form larger necrotic areas. Infected leaves may drop prematurely, weakening the plant.
To manage the disease, infected plant parts should be removed as soon as possible and destroyed. Fungicides containing copper or chlorothalonil may be applied, following the manufacturer's instructions. Additionally, proper cultural practices, including providing adequate air circulation and avoiding overhead irrigation, can prevent the spread of the disease.
Pest Management
Mertensia oblongifolia var. amoena is also relatively resistant to pests. However, it may be attacked by several insects, including aphids and spider mites. Aphids are small, soft-bodied insects that feed on plant juices and secrete honeydew, which attracts ants and promotes the growth of sooty mold. Spider mites are tiny pests that suck plant sap, causing leaves to turn yellow or bronzed and to drop prematurely.
To manage aphids, natural enemies, such as ladybugs, lacewings, and parasitic wasps, can be released or encouraged by planting nectar-rich flowers nearby. Insecticidal soap or neem oil can also be used to control infestations, following the manufacturer's directions. To manage spider mites, misting the plant with water and using a high-pressure hose to wash them off may help. In severe infestations, insecticidal soap or horticultural oil can be used carefully, following the manufacturer's instructions.
