Overview
Achillea millefolium var. gigantea, also known as giant yarrow, is a perennial herbaceous plant belonging to the Asteraceae family. It is native to western North America, particularly in the southwestern United States and northern Mexico. This plant is an attractive addition to the garden, and it has been widely used for medicinal and ornamental purposes.
Appearance
Achillea millefolium var. gigantea grows up to 3 feet tall and up to 2 feet wide. It has a woody stem that is erect and covered with fine hairs. The large leaves are almost fern-like and are about 4 inches long with multiple small lobes. The plant produces clusters of small, tightly packed, white to pale pink flowers that bloom in summer. The flowers have a distinct aroma that is spicy and slightly sweet. They also attract a variety of pollinators such as bees and butterflies.
Uses
The giant yarrow has several uses, both medicinal and ornamental. It is commonly used in herbal medicine to treat various conditions such as fever, colds, digestive problems, and menstrual cramps. The leaves and flowers of the plant are infused in hot water to make tea. It is also believed to have antiseptic and anti-inflammatory properties. In the garden, Achillea millefolium var. gigantea is a popular choice for rock gardens, borders, and naturalized areas. It is also ideal for attracting beneficial insects and pollinators. The plant growth habit makes it an excellent cut flower for floral arrangements. It requires well-drained soil and full sunlight to thrive.
Common Names
The Achillea millefolium var. gigantea is commonly known as giant yarrow or woolly yarrow due to its soft, furry leaves. Other common names include Western yarrow, Fern-leaf yarrow, and Snake's Grass.
Light Requirements
Achillea millefolium L. var. gigantea (Pollard) Nobs is a plant that thrives well in full sun conditions. It requires a minimum of six hours of direct sunlight exposure each day to thrive optimally. It is essential to place the plant in an area where it will not be overshadowed by tall trees or nearby structures.
Temperature Requirements
Achillea millefolium L. var. gigantea (Pollard) Nobs is a hardy perennial that does well in a wide range of temperatures. The plant can tolerate hot and dry conditions, as well as cold and moist climates. The ideal temperature range for the plant is between 60-75°F (16-24°C). In colder regions, the plant may go dormant during winter and regrow in spring.
Soil Requirements
Achillea millefolium L. var. gigantea (Pollard) Nobs grows best in well-draining soils. The soil should be moist but not waterlogged, and it should have a pH range of 6.0 to 7.0. The plant can also grow in poor soils and can even tolerate some drought conditions. It is essential to avoid heavy clay soils, as they tend to hold excessive moisture and may lead to root rot. Fertilization is recommended to maintain healthy growth and flowering during the growing season.
Cultivation of Achillea millefolium L. var. gigantea (Pollard) Nobs
Achillea millefolium L. var. gigantea is a perennial plant that can grow up to 3 feet tall with aromatic leaves and clusters of small white or pink flowers. This plant can be grown in a variety of soil types but prefers well-draining soils that are rich in organic matter.
If cultivating from seeds, it is best to start indoors 6-8 weeks before the last expected frost date and then transplant to the garden after the danger of frost has passed. Alternatively, plants can be propagated by division in the spring or fall.
Watering Needs of Achillea millefolium L. var. gigantea (Pollard) Nobs
Achillea millefolium L. var. gigantea prefers moderate watering and does not tolerate water-logged soils. Water the plant deeply once a week during the growing season and avoid overhead watering to prevent the spread of fungal diseases. The plant is drought-tolerant once established and does not require additional watering during periods of drought.
Fertilization of Achillea millefolium L. var. gigantea (Pollard) Nobs
The plant does not require heavy fertilization but benefits from a light application of a balanced slow-release fertilizer in the early spring. Apply the fertilizer at the base of the plant, being careful not to apply too close to the stem to prevent stem rot.
Pruning of Achillea millefolium L. var. gigantea (Pollard) Nobs
Pruning is not necessary for the plant’s growth but may help to maintain its appearance and remove spent flowers. Cut back the plant by one-third after the first flush of flowers has faded to promote a second flush of blooms. Deadhead regularly to prevent the plant from going to seed and to promote a longer blooming period.
Propagation of Achillea millefolium L. var. gigantea (Pollard) Nobs
Achillea millefolium L. var. gigantea (Pollard) Nobs, commonly known as 'Giant Yarrow' or 'Western Yarrow,' is a perennial herbaceous plant species that belongs to the Asteraceae family. It is a native plant of Western North America and is found in varied habitats like meadows, disturbed areas, and roadsides. Propagation of this plant species can be done vegetatively or via seed.
Propagation via Seed
The propagation of 'Giant Yarrow' via seeds can be done indoors or directly outdoors in the garden.
If propagating indoors, sow the seeds in late winter (February/March) in seed-starting trays with a well-draining seed starting mix. Sow the seeds at a depth of about 1/8 inches and place the trays in a bright location with temperatures of about 60-70°F. Keep the soil consistently moist, but not waterlogged. The seeds would germinate in 14-21 days.
If the propagation is directly outdoor, sow the seeds in the prepared garden soil in spring (April/May) or fall (September/October). Sow the seeds on the soil surface and cover them with a thin layer of soil. Water the soil thoroughly with a gentle stream of water, without disturbing the seeds. The seeds would germinate in about 2 weeks. Prune your 'Giant Yarrow' once the seedlings grow to about 3-4 inches tall, leaving only the strongest seedling.
Propagation via Vegetative Cuttings
Propagation of 'Giant Yarrow' via vegetative cuttings can be done in late spring to early summer.
Take 3-4 inch cutting from a healthy and mature 'Giant Yarrow' plant, making an angled cut with a sharp and sterile knife. Strip off the lower leaves, leaving only 2-3 leaves on the top. Dip the cuttings in rooting hormone powder and gently tap off the excess powder. Insert the cuttings in a pot with a well-draining potting mix, and water them until the soil is evenly moist. Keep the pot in a bright but shaded location with temperatures of around 70°F. Keep the potting mix moist but not waterlogged.
The cuttings will root in about 2-3 weeks, after which they can be transplanted into a garden or moved to larger pots.
Disease Management
Achillea millefolium L. var. gigantea (Pollard) Nobs is a relatively hardy plant species that is tolerant to many diseases. However, some diseases may still affect the plant, reducing its productivity and quality. Here are some common diseases and ways to manage them:
- Powdery mildew: This is a fungal disease that appears as white, powdery spots on the foliage. To manage it, ensure proper air circulation around the plant, avoid overhead watering, and apply fungicides as recommended by a specialist.
- Crown rot: Crown rot is caused by soil-borne fungi and bacteria, leading to the death of the plant's crown. To manage it, avoid planting Achillea millefolium L. var. gigantea in poorly-drained soil and apply fungicides as recommended.
- Root rot: Root rot is also caused by soil-borne pathogens that lead to the death of the plant's roots. To manage it, avoid over-watering the plant and plant it in well-drained soil. Apply fungicides or bio-control agents as recommended.
Pest Management
Achillea millefolium L. var. gigantea (Pollard) Nobs is also susceptible to pest attacks, which can reduce its yields and quality. Here are common pests and ways to manage them:
- Aphids: Aphids are small, sap-sucking insects that can cause stunted growth and yellowing of the plant. To manage them, use insecticidal soaps or oils, prune infested branches, and encourage natural predators such as ladybugs and lacewings.
- Spider mites: Spider mites are tiny creatures that feed on the plant's sap, leading to yellowing and drying of leaves. To manage them, use insecticidal soaps or oils, increase humidity around the plant, and prune infested branches.
- Thrips: Thrips are small insects that feed on the plant's foliage, causing silvering or bronzing of the leaves. To manage them, prune infested branches, use yellow sticky traps, or use biological control agents like predatory mites.
Regular monitoring of the plant for any signs of disease or pest infestation is critical for early detection and management. Additionally, it is vital to maintain plant cleanliness and ensure proper sanitation to prevent the spread of diseases and pests. When using pesticides or fungicides, always follow the manufacturer's instructions for safe and effective use.
