Origin
Penstemon davidsonii Greene var. menziesii (Keck) Cronq. is native to the Western United States, particularly in California, Oregon, and Nevada.
Common Names
The plant is commonly known as Menzies' beardtongue, Menzies' penstemon, and Davidson's penstemon, named after Scottish naturalist Archibald Menzies and American botanist George Davidson.
Uses
Penstemon davidsonii Greene var. menziesii is often used as an ornamental plant due to its striking appearance and easy maintenance. Its flowers attract bees, hummingbirds, and butterflies, making it a popular choice for pollinator gardens. The plant is also used in landscaping and wildflower restoration projects.
General Appearance
Penstemon davidsonii Greene var. menziesii is a perennial herb that grows up to 3 feet tall. It has lance-shaped leaves that are gray-green in color and hairy. The plant produces showy clusters of bright pink to purple-blue tubular flowers with white markings and long stamens in late spring to early summer. The flowers are about an inch long and are arranged in branching spikes. The plant prefers well-drained soil and full sun to partial shade.
Light Requirements:
Penstemon davidsonii var. menziesii prefers full sunlight to partial shade for ideal growth. It can handle dappled shade, but it may impact flowering and overall growth. In areas with hot summers, some afternoon shade may be beneficial for the plant.
Temperature Requirements:
This plant can be found naturally at a wide range of elevations, indicating that it can tolerate a variety of temperatures. However, it prefers a mild climate with moderate temperatures. Ideal temperature range for the growth of Penstemon davidsonii var. menziesii is between 70-80°F (21-27°C) during the day and in the 50s°F (10s°C) at night. During winter, the temperature does not usually cause any problem as long as the plant is protected from harsh winds and heavy snow.
Soil Requirements:
Penstemon davidsonii var. menziesii grows well in well-draining soils. It prefers moist, but not soggy, soil. This plant can tolerate most soil types, including loamy, sandy, or rocky soils. Soil pH should be 6.0-7.5. Avoid poorly draining soils as stagnant water can lead to root rot.
Cultivation Methods
Penstemon davidsonii Greene var. menziesii (Keck) Cronq. is native to the Sierra Nevada mountain range in California and prefers well-draining soil in full sun to partial shade. It is recommended to plant this species in early spring or fall.
You can propagate this plant through seed or stem cuttings. For seeding, sow seeds indoors 8-10 weeks before the last frost date or directly in the ground after the danger of frost has passed. For stem cuttings, take cuttings from the parent plant in early summer or fall and root them in moist soil.
Watering Needs
Penstemon davidsonii Greene var. menziesii (Keck) Cronq. requires moderate watering. It should be watered thoroughly once or twice a week, or when the top inch of soil is dry. However, avoid over-watering as it can lead to root rot.
It is also recommended to water this plant in the morning so that the foliage has enough time to dry during the day, reducing the risk of fungal diseases.
Fertilization
Penstemon davidsonii Greene var. menziesii (Keck) Cronq. does not require much fertilization. However, you can add compost or a balanced fertilizer in early spring and mid-summer to provide extra nutrients.
Avoid using high-nitrogen fertilizers, as they can promote excessive foliage growth and reduce flower production.
Pruning
Penstemon davidsonii Greene var. menziesii (Keck) Cronq. does not require heavy pruning. You can deadhead faded flowers to encourage new growth and prolong the blooming period.
You can also prune back the stems by half after flowering to promote bushiness. However, avoid pruning too much or too late in the season, as it can affect the next season's flowers.
Propagation of Penstemon davidsonii Greene var. menziesii (Keck) Cronq.
Penstemon davidsonii Greene var. menziesii (Keck) Cronq. is a beautiful flowering plant that is native to California. The plant is popularly grown in gardens and landscaped areas as it is fairly easy to propagate. There are a few different propagation methods that can be used to propagate this plant.
Seed Propagation
Penstemon davidsonii Greene var. menziesii (Keck) Cronq. can be propagated from seeds. Collect the seeds from mature pods that have dried out in the fall. Soak the seeds in water overnight to soften their coat. Then, stratify the seeds at around 40°F for 30-60 days before they are sown in the spring.
Cuttings Propagation
Penstemon davidsonii Greene var. menziesii (Keck) Cronq. can also be propagated from cuttings. To propagate from cuttings, take stem cuttings of around 3-5 inches from an existing plant in the spring or fall. Removal of the bottom leaves and hormones are sometimes helpful. Plant the cuttings in well-draining soil with a good moisture content, and provide a cover to maintain humidity. Roots will form within 3-4 weeks.
Division Propagation
Penstemon davidsonii Greene var. menziesii (Keck) Cronq. can be propagated by division. Divide the plant during the fall to spring months. Split the root ball into several sections, ensuring that each section has at least one stem, and replant in well-draining soil with a good moisture content. This method is the easiest, but the plant may take longer to establish and grow.
Disease Management
Penstemon davidsonii Greene var. menziesii (Keck) Cronq. are quite hardy and resistant to most diseases. However, certain conditions may lead to diseases such as:
- Powdery mildew: This is a fungal disease that affects the leaves, causing a powdery grey or white covering. It can be prevented by ensuring good air circulation around the plant and avoiding overcrowding.
- Crown rot: This is a fungal disease that causes the rotting of the stem and roots. It is commonly caused by overwatering or poorly-draining soil. To prevent this, ensure that the soil is well-drained and avoid overwatering the plants.
- Root rot: This is another fungal disease that affects the roots and causes them to rot. It occurs in poorly-draining soil and is exacerbated by overwatering. To avoid root rot, ensure that the soil is well-drained.
If you notice any signs of disease, such as discolored or withered leaves, remove affected leaves and destroy them to prevent further spread.
Pest Management
Penstemon davidsonii Greene var. menziesii (Keck) Cronq. are generally resistant to pests and do not require much pest control. However, some pests that may affect them include:
- Aphids: These are small, soft-bodied insects that often congregate on new growth or the underside of leaves. They can be controlled by removing them manually or by spraying with insecticidal soap or neem oil.
- Spider mites: These are tiny arachnids that can cause yellowing and stippling of leaves. They can be controlled by regularly spraying the plant with water or neem oil.
If pest infestations are severe, chemical insecticides can be used as a last resort. However, it is recommended to try non-toxic methods first.
