Origin
Lupinus polyphyllus Lindl. ssp. polyphyllus var. grandifolius (Lindl. ex J.G. Agardh) Torr. & Gray, commonly known as Large-leaved Lupine, is a perennial plant species from the genus Lupinus. The plant is native to North America, particularly in the Pacific Northwest region of the United States and British Columbia, Canada.
Common Names
The plant has several common names, including Large-leaved Lupine, Bigleaf Lupine, and Washington Lupine.
Uses
The Large-leaved Lupine plant is often grown as a garden ornamental. Its showy blue flowers and lush green foliage make it an attractive addition to any garden or landscape. Aside from its ornamental use, the plant has been used for medicinal purposes. The Native Americans used the plant to make poultices and liniments for a wide range of ailments, such as stomach cramps, headaches, and skin problems.
General Appearance
The Large-leaved Lupine plant is a perennial herb that can grow up to 120 cm tall. It has a deep taproot and erect, hairy stems that are typically green. The plant's leaves are alternate and palmately compound, with 7 to 11 leaflets. The leaflets are oval to lance-shaped and can grow up to 15 cm long. The plant blooms in late spring to early summer, with showy blue flowers that are arranged in a tapering, terminal raceme. The flowers are about 1.5 cm long and have a distinctly sweet fragrance. The plant produces pods that contain seeds, which can be used for food or replanting.
Light Requirements
Lupinus polyphyllus Lindl. ssp. polyphyllus var. grandifolius requires full sun to partial shade for optimal growth. It can tolerate some shade but will not bloom as profusely as in full sun.
Temperature Requirements
Lupinus polyphyllus Lindl. ssp. polyphyllus var. grandifolius prefers cool temperatures and can tolerate frost. It grows well in USDA hardiness zones 3 to 8. It is important to provide the plant with temperatures between 55 to 70°F (13 to 21°C) during its flowering period.
Soil Requirements
The plant prefers moist, fertile, well-draining soils that are rich in organic matter. It does not tolerate standing water and poorly-draining soils. A soil pH between 6.0 and 7.5 is ideal for growth. Amending the soil with compost or well-rotted manure before planting can be beneficial for the plant's growth and health.
Cultivation Methods
Lupinus polyphyllus Lindl. ssp. polyphyllus var. grandifolius (Lindl. ex J.G. Agardh) Torr. & Gray grows best in well-draining soil with a neutral to slightly acidic pH level. It prefers full sunlight but can tolerate some shade. When planting, ensure that there is enough space between each plant, as they can grow up to 4 feet tall and 2-3 feet wide. The best time to plant is in the spring or fall when the soil is moist and temperatures are mild.Watering Needs
Lupinus polyphyllus Lindl. ssp. polyphyllus var. grandifolius (Lindl. ex J.G. Agardh) Torr. & Gray requires moderate watering. It is important not to overwater, as this can lead to root rot. Water the plant deeply about once a week or when the top 1-2 inches of soil feel dry. However, adjust watering depending on the weather and soil conditions.Fertilization
Lupinus polyphyllus Lindl. ssp. polyphyllus var. grandifolius (Lindl. ex J.G. Agardh) Torr. & Gray benefits from a balanced fertilizer every spring before new growth begins. Work the fertilizer into the soil around the base of the plant. Avoid using high-nitrogen fertilizers, as this can lead to excessive leaf growth at the expense of flower production.Pruning
Pruning is not necessary for Lupinus polyphyllus Lindl. ssp. polyphyllus var. grandifolius (Lindl. ex J.G. Agardh) Torr. & Gray. However, deadheading spent blooms can encourage the plant to produce more flowers throughout the growing season. When cutting back old flowers, take care not to damage any new buds or emerging leaves. After the plant has finished blooming for the season, you may also cut back the entire plant to just above the ground to help promote healthy growth for the following year.Propagation of Lupinus polyphyllus Lindl. ssp. polyphyllus var. grandifolius (Lindl. ex J.G. Agardh) Torr. & Gray
Lupinus polyphyllus Lindl. ssp. polyphyllus var. grandifolius (Lindl. ex J.G. Agardh) Torr. & Gray, commonly known as the large-leaved lupine, is a flowering perennial plant that is native to western North America. This plant can be propagated through seed or vegetative means, such as cuttings or division.
Propagation by Seed
Seed propagation is the most common and easiest method of propagating Lupinus polyphyllus Lindl. ssp. polyphyllus var. grandifolius. The seeds should be sown in the late fall or early spring, after they have been scarified or soaked in water overnight to break down their hard seed coat. The seeds should be sown at a depth of approximately 1 inch in well-draining soil, and kept consistently moist until germination occurs. Germination can take several weeks to a few months, and the seedlings should be transplanted when they have reached a height of 2-3 inches.
Propagation by Cuttings
Propagation by cuttings can be done in the spring or fall. Select healthy stems that have not yet flowered, and cut them into 3-4 inch sections. Remove the lower leaves and dip the cut end in rooting hormone. Plant the cuttings in pots or directly in the ground in a well-draining soil mix, and keep the soil consistently moist until roots have formed. Once the cuttings have rooted, they can be transplanted to their permanent location.
Propagation by Division
Propagation by division can be done in the spring or fall when the plant is dormant. Carefully dig up the plant and separate the root ball into sections, making sure each section has a portion of the root system and several shoots. Replant the sections in a well-draining soil mix and keep the soil consistently moist until they have become established.
Common diseases affecting Lupinus polyphyllus Lindl. ssp. polyphyllus var. grandifolius (Lindl. ex J.G. Agardh) Torr. & Gray
Lupinus polyphyllus Lindl. ssp. polyphyllus var. grandifolius (Lindl. ex J.G. Agardh) Torr. & Gray is vulnerable to a range of fungal diseases, which are more likely to occur in wet weather. These diseases include:
- Root rot: caused by soil-borne fungi that attack the roots, leading to wilting and yellowing of the foliage.
- Powdery mildew: a fungal disease that appears as a white powdery growth on the leaves, ultimately leading to leaf drop.
- Rust: a fungal disease characterized by orange-brown spore masses on leaves and stems.
Managing diseases affecting Lupinus polyphyllus Lindl. ssp. polyphyllus var. grandifolius (Lindl. ex J.G. Agardh) Torr. & Gray
To manage these diseases, it is important to ensure good cultural practices. Water the plants at the base to avoid wetting the foliage, and thin the plants to improve air circulation. Adding compost or organic matter to the soil can also help improve soil health and drainage, reducing the likelihood of root rot.
If diseases do arise, it may be necessary to use fungicides. Consult with a local extension office or nursery to determine the best fungicide for the specific disease affecting your plants.
Common pests affecting Lupinus polyphyllus Lindl. ssp. polyphyllus var. grandifolius (Lindl. ex J.G. Agardh) Torr. & Gray
Common pests that can affect Lupinus polyphyllus include:
- Aphids: small, soft-bodied insects that can be found in large congregations on the growing tips of plants.
- Slugs and snails: mollusks that can damage leaves and stems by leaving large holes in the foliage.
- Thrips: tiny, winged insects that can cause damage to the flowers by feeding on them.
Managing pests affecting Lupinus polyphyllus Lindl. ssp. polyphyllus var. grandifolius (Lindl. ex J.G. Agardh) Torr. & Gray
To manage the pest population, it is important to remove any damaged plant material or debris around the plants. This will help to eliminate any potential hiding places for pests. Additionally, using insecticidal soap or neem oil can be effective in controlling aphids and thrips. Slugs and snails can be controlled by using a beer trap or applying diatomaceous earth around the plants.
Remember, prevention is key when it comes to pests and diseases. By maintaining good cultural practices and keeping the plants healthy, you can help prevent outbreaks from occurring in the first place.
