General Information
Lithospermum obtusifolium I.M. Johnston, commonly known as bluntleaf or blunt-leaved stoneseed, belongs to the Boraginaceae family and is native to North America. It is a perennial herbaceous plant that typically grows up to 1-3 feet tall, and it is commonly found in prairies, savannas, and open woods.
Appearance
The plant has an upright and spindly stem that branches out at the top. The leaves are simple, alternate, and lance-shaped with a blunt tip, hence the common name. They are hairy and up to 5 inches long. The flowers are small and tubular, about 1/4 to 1/2 inch wide, and are typically pinkish-purple with five petals that split open when the flower matures. The flowers emerge from May to August, and the plant's fruit is a brown nutlet, typically about 1/8 inch long.
Uses
Lithospermum obtusifolium has been used for multiple medicinal purposes. Native Americans used infusions of the plant to treat kidney, bladder, and liver problems. It was also used to treat snake bites, cuts, and bruises. Nowadays, the plant has not gone through significant research for its medicinal uses, but it is still used in some natural treatments. It is not used as a food source for any animal and is considered poisonous when eaten in large amounts by humans and livestock.
Overall, Lithospermum obtusifolium is an interesting and appealing plant that has been part of North America's history and the native culture's holistic treatments. Its flowers are especially charming and eye-catching, making it a potential garden staple in the present day.Light Requirements
Lithospermum obtusifolium is a plant that belongs to the family Boraginaceae. It requires full sun to partial shade to grow and it cannot tolerate complete shade. The plant grows in open areas such as meadows, grasslands, and limestone hills.
Temperature Requirements
Lithospermum obtusifolium is a hardy plant that can tolerate a wide range of temperatures. It can grow in USDA hardiness zones 3-9, which makes it suitable for most regions of the United States. However, the plant prefers cooler temperatures and grows best in temperatures between 60-80°F (15-27°C).
Soil Requirements
The plant grows best in well-drained soils that are rich in organic matter. It prefers soils that are alkaline to slightly acidic with a pH range of 6.0-7.8. Lithospermum obtusifolium can tolerate a wide range of soils including clay, loam, and sand. However, it cannot tolerate waterlogged soils or soils that are constantly wet.
Cultivation Methods
Lithospermum obtusifolium I.M. Johnston is a hardy perennial that thrives in well-drained soil. It prefers full sun exposure and can withstand droughts and occasional flooding during rainy seasons. It's best to plant it in areas with temperatures ranging from 17°C to 27°C, as it doesn't do well in environments that are too hot or too cold.
Watering Needs
When it comes to watering this plant, you'll want to ensure you're not overwatering it. Water it deeply once every week, or more frequently if the soil dries out faster than usual. Avoid watering unless the top inch of soil is dry to the touch and make sure to water at the base of the plant to prevent foliage damage.
Fertilization
To ensure that Lithospermum obtusifolium I.M. Johnston yields healthy growth and blooms, fertilization is crucial. Apply a slow-release fertilizer with a balanced ratio of nitrogen, phosphorus, and potassium (N-P-K) right before spring to encourage vigorous growth. Repeat the application every six to eight weeks during the growing season.
Pruning
Lithospermum obtusifolium I.M. Johnston requires little to no pruning. However, if you notice any dead, diseased, or damaged foliage, prune them out immediately to prevent further damage. If you want to control the plant's size, you can prune it in late winter or early spring before new growth appears.
Propagation of Lithospermum obtusifolium
Lithospermum obtusifolium is a plant that can be propagated through several methods, but the most common is through seed propagation and division.
Seed Propagation
The seeds of Lithospermum obtusifolium can be sown directly into the ground in the fall or spring. The ideal time to sow the seeds is in late fall or early winter before the ground freezes. If sowing in spring, it is best to wait until the soil has warmed up and all danger of frost has passed.
The seeds should be sown at a depth of ¼ inch and spaced 6-12 inches apart. The seeds require light for germination, so they should not be covered with soil. It is important to keep the soil moist until the seeds germinate, which usually takes about 2-4 weeks.
Once the seedlings emerge, they should be thinned to 6-12 inches apart to allow sufficient space for growth. Seed-grown plants may take up to 2-3 years to reach maturity and start producing flowers.
Division
Lithospermum obtusifolium can also be propagated through division. The best time to divide the plant is in the early spring, just as new growth is emerging.
To divide the plant, carefully dig it up and separate the clumps into smaller sections. Each section should have at least one shoot and a portion of the root system. The divided sections can then be planted in their new location at the same depth they were originally growing.
It is important to water the newly transplanted divisions well and keep the soil moist until they establish a new root system. It may take a few weeks for the divisions to become established and start growing.
Disease Management
Lithospermum obtusifolium is generally resistant to diseases, but it can still be affected by some fungal infections, such as leaf spots and powdery mildew.
To manage leaf spots, it is recommended to remove and destroy infected leaves as soon as they are noticed to prevent the spread of the disease. Avoid overhead watering and make sure to maintain good air circulation around the plant.
Powdery mildew can be controlled through the use of fungicides, such as neem oil or potassium bicarbonate, and by providing adequate sunlight and air circulation. Removing infected foliage can also help prevent the spread of the disease.
Pest Management
Lithospermum obtusifolium can attract some pests, including aphids, spider mites, and slugs.
To manage aphids, it is recommended to encourage natural predators, such as ladybugs or lacewings, or use insecticidal soaps or neem oil. Regularly inspecting and removing infested leaves can also help control aphid populations.
Spider mites can be controlled through the use of insecticidal soaps or neem oil, and by regularly spraying the plants with water to increase humidity levels.
Slugs can be managed through handpicking, applying diatomaceous earth or copper strips around the plants, or using slug bait. It is important to remove any hiding places, such as boards or rocks, where slugs can hide during the day.
