Origin
Penstemon glandulosus Dougl. var. glandulosus, commonly known as sticky penstemon, is a plant species native to western North America.
Common Names
Aside from sticky penstemon, the plant is also known by other names such as glandular penstemon, glandular beardtongue, and woolly beardtongue.
Uses
The sticky penstemon is a popular ornamental plant for gardens, landscaping, and as cut flowers for floral arrangements. The plant is also known for its medicinal properties and has been used by native tribes to treat various ailments like fever, headaches, and muscle pain. Additionally, the plant's stems and leaves are known to create a foam-like substance when mixed with water, which was used by some tribes as soap.
General Appearance
The sticky penstemon is a herbaceous perennial plant that can grow up to 2 meters in height. It has lance-shaped leaves that are 5 to 15 centimeters long and arranged in pairs along the stems. The plant produces multiple spikes of showy, tubular-shaped flowers that can be white, pink, red, purple, or blue. The flowers have two lips, the upper lip having two lobes and the lower lip having three lobes. The plant's stems and leaves are covered in glandular hairs, hence the common name sticky penstemon.
Growth Conditions for Penstemon glandulosus Dougl. var. glandulosus
Light: Penstemon glandulosus Dougl. var. glandulosus requires full sun to partial shade for optimal growth. In areas with hot summers, it is best to provide the plant with afternoon shade to prevent leaf scorching.
Temperature: This plant species is native to western North America and can tolerate a range of temperatures from hot summers to cold winters. It typically grows in USDA hardiness zones 5-9. In colder climates, it may die back to the ground in winter and sprout new growth from the roots in spring.
Soil: Penstemon glandulosus Dougl. var. glandulosus prefers well-draining, sandy or loamy soils, but it can also grow in rocky or clay soils as long as they are not waterlogged. The plant is adapted to dry conditions and can tolerate some drought, but it will benefit from occasional watering during extended dry periods.
Cultivation Methods for Penstemon Glandulosus Dougl. var. Glandulosus
Penstemon Glandulosus Dougl. var. Glandulosus, commonly known as the sticky penstemon, requires full sunlight to thrive. Plant the sticky penstemon in well-draining soil with a pH range of 6 to 8. This species of penstemon can grow up to 60 cm (2 feet) in height and up to 90 cm (3 feet) in width. It is essential to space the plants at least 60 cm (2 feet) apart to avoid overcrowding, which can lead to disease and stunted growth.
Watering Needs for Penstemon Glandulosus Dougl. var. Glandulosus
Sticky penstemon is a drought-tolerant plant, but regular watering is necessary for optimal growth. Water the plants once a week, especially during the hot summer months, when the soil is dry. Avoid overwatering, as it can cause root rot, yellowing leaves, and stunted growth. Mulch the soil around the plant to conserve moisture and keep the roots cool during hot weather.
Fertilization of Penstemon Glandulosus Dougl. var. Glandulosus
The sticky penstemon needs a nutrient-rich soil to perform well. Before planting, add well-rotted manure or compost to the soil to boost its fertility. In subsequent years, top-dress the soil around the plant with compost or aged manure annually to maintain soil fertility. Avoid over-fertilization, which can lead to weak growth, few flowers, and an increased susceptibility to disease.
Pruning of Penstemon Glandulosus Dougl. var. Glandulosus
Penstemon Glandulosus Dougl. var. Glandulosus is a low-maintenance plant that requires minimal pruning. Deadhead the flowers after they have faded to promote continuous blooming. Cut back the entire plant to a height of 15-20 cm (6-8 inches) in the early spring to encourage new growth and maintain its shape. Removal of any dead, diseased, or damaged stems is essential to the plant's overall health.
Propagation of Penstemon glandulosus Dougl. var. glandulosus
Penstemon glandulosus Dougl. var. glandulosus is a beautiful perennial plant that belongs to the family Plantaginaceae. The plant usually grows up to a height of 1-3 feet and has several stems. The herb is native to western North America and is commonly used for its medicinal properties.
Propagation of Penstemon glandulosus Dougl. var. glandulosus can be done in several ways, including seed propagation, division, and stem cuttings.
Seed Propagation
Seed propagation is the most common method used for Penstemon glandulosus Dougl. var. glandulosus. Seeds can be collected manually from the mature plants during autumn and winter. The collected seeds must be dried thoroughly and stored in a cool and dry place. The seeds require stratification to stimulate the natural germination process. Stratification can be done by planting the seeds ¼ inch deep in a potting mix and placing them in a refrigerator for at least 4- weeks. After stratification, the seeds must be sown in a well-draining soil mix and kept moderately moist.
Division
Division is another method used for propagating Penstemon glandulosus Dougl. var. glandulosus. This method is often preferred for mature plants that have grown too large for their container or location. The plant must be lifted carefully with a spade and separated into several sections, each containing new shoots and roots. The divided sections must be replanted immediately in a well-draining soil mix and watered thoroughly.
Stem Cuttings
Stem cuttings are another reliable way to propagate Penstemon glandulosus Dougl. var. glandulosus. The cuttings must be taken from a healthy plant during spring or summer and must have several nodes. The cuttings should be 4-6 inches long and treated with rooting hormone before planting them into a potting mix. The cuttings must be kept under high humidity and mild sunlight conditions until they develop roots.
Disease Management
Penstemon glandulosus Dougl. var. glandulosus is susceptible to a range of diseases. The common diseases that affect this plant include powdery mildew, root rot, and rust.
Powdery mildew is a fungal disease that causes white powder-like patches on the leaves of the plant. To manage powdery mildew, use a fungicide as per the manufacturer's instructions. Also, maintain proper spacing between the plants to increase air circulation.
Root rot is a deadly disease caused by soilborne fungi. To manage root rot, avoid overwatering and provide proper drainage. Ensure that the soil is well-draining and enriched with organic matter. Additionally, avoid planting Penstemon glandulosus Dougl. var. glandulosus in the same location after removing infected plants.
Rust is a fungal disease that causes rust-colored spots on the leaves of the plant. To manage rust, prune and discard infected leaves and apply a fungicide to prevent further spread of the disease.
Pest Management
Penstemon glandulosus Dougl. var. glandulosus is resistant to most pests. However, it can be affected by aphids, mites, and nematodes.
Aphids are small, pear-shaped insects that suck sap from the plant. They cause yellowing of the leaves and stunted growth. To manage aphids, physically remove them with a strong stream of water or use an insecticidal soap as per the manufacturer's instructions.
Mites are tiny pests that can cause damage to Penstemon glandulosus Dougl. var. glandulosus. They suck the sap from the plant, causing leaves to curl and turn yellow. To control mites, use a miticide as per the manufacturer’s instructions. Additionally, remove severely infected plants to avoid the spread of mites.
Nematodes are microscopic worms that invade the roots of the plant, causing stunted growth and wilting. To manage nematodes, use a nematicide or solarize the soil by covering it with a clear plastic sheet for six weeks during the hot summer months.
