Overview
Achillea borealis Bong. is a perennial herbaceous plant that belongs to the Asteraceae family.
Origin
Achillea borealis Bong. is commonly found across most of Canada and in the northernmost contiguous United States.
Common Names
This plant is commonly known as Borealis yarrow, Northern yarrow, and Fernleaf yarrow.
Appearance
Achillea borealis Bong. produces flat-topped clusters of small, white to pink flowers from early to late summer. The plant grows up to 1 meter tall and has fern-like leaves that are finely divided. The leaves and stem have a pleasant fragrance when crushed.
Uses
Achillea borealis Bong. has been used traditionally in the treatment of various ailments. The leaves can be made into a tea and used as a natural remedy for digestive issues and skin problems. Additionally, the plant is often used for ornamental purposes in gardens and landscapes.
Light Requirements
Achillea borealis Bong. thrives in full sun to partial shade conditions. The plant is equipped to handle a wide range of light intensities, but it prefers sunny locations. Full sunlight conditions stimulate better growth, more abundant flowering, and robustness, while partial shade can promote taller growth and less profuse flowering.
Soil Requirements
The plant can live in a wide range of soil types, including sandy, loamy, or rocky soils. Ideally, Achillea borealis Bong. prefers to grow in moist, well-drained, and moderately fertile soils. The soil's pH range should be between 5.5 to 7.2. The plant also requires good air circulation, which means the soil should not be too compact or waterlogged.
Temperature Requirements
Achillea borealis Bong. does well in cold temperatures. The plant can flourish in USDA hardiness zones 2-7, which have average minimum temperatures of -50F to 5°F. The ideal growth temperature range for this plant is between 50°F and 70°F. The plant's tolerance for cold temperatures makes it a suitable plant to grow in alpine gardens and in cooler regions, where it can grow without a lot of maintenance.
Cultivation
Achillea borealis Bong. is commonly known as Northern yarrow. It's a perennial plant that prefers dry to medium moisture soils. You can cultivate this plant by direct seeding or transplanting.
If you opt for direct sowing, make sure to attain good seed to soil contact. Till the soil and remove any debris or rocks before planting the seeds. Ensure the planting depth is not more than 3mm deep. The Northern yarrow seeds should germinate within 7-14 days.
For transplants, plant them in areas with well-draining soils. The Northern yarrow requires a lot of sunlight, so ensure to plant them in areas exposed to full sunlight. Space out each plant at least one foot apart.
Watering Needs
The Northern yarrow is adapted to dry soils, but it still requires moderate watering until the roots are established. Water newly planted seedlings every week or two if there is no rain.
After establishment, the Northern yarrow is drought-resistant. The plant can survive long periods without water. However, it's crucial to water the plant during prolonged droughts occasionally. When irrigating, ensure not to overwater the plant as it can lead to root rot.
Fertilization
The Northern yarrow does not require much fertilization if planted in fertile soil. However, you can add a slow-release fertilizer during planting or topdress with compost after the growing season.
If you have poor soil, you can fertilize the plant with a balanced fertilizer after six weeks. Apply a teaspoon of the fertilizer once a month until the growing season ends.
Pruning
Deadhead the Northern yarrow to prolong the blooming period. Cut back the plant when the blooms start to fade. Prune the plant in the early spring to remove any dead or damaged stems. You can also divide the plant every two to three years to prevent overcrowding.
The Northern yarrow is easy to maintain, and with proper care, it can last for years.
Propagation of Achillea borealis Bong.
There are various methods of propagating Achillea borealis Bong., a herbaceous perennial that belongs to the Asteraceae family.
Seed Propagation
The most common and easiest way to propagate Achillea borealis Bong. is through seeds. The plant produces seeds in small brown seedheads in late summer or early fall. The seeds can be harvested by cutting the seedheads and placing them upside down in a paper bag to air dry. Once the seeds are completely dry, they can be stored in a cool, dry place until the following spring.
To germinate the seeds, they should be sown in early spring in a seed-starting tray filled with a well-draining seed-starting mix. Place the tray in a warm, sunny location and keep the soil moist. The seeds will germinate in two to three weeks. Once the seedlings have several sets of true leaves, they can be transplanted into individual pots or directly into the garden.
Division
Achillea borealis Bong. can also be propagated through division. This method is best done in the fall or spring when the plant is dormant. To divide the plant, carefully dig up the entire clump and separate it into smaller sections with a sharp garden knife. Each section should have a healthy root system and several stems. Replant the divisions in a new location or in individual pots.
Cuttings
Achillea borealis Bong. can be propagated through stem cuttings, though it is a bit more challenging than the other methods. Cuttings should be taken in late spring or early summer when the plant is actively growing. Choose a healthy stem and snip off a 3-5 inch section just below a node. Remove the lower leaves from the stem and dip the cut end in rooting hormone powder. Plant the cutting in a well-draining potting mix and keep it moist. It should root in four to six weeks.
Propagation of Achillea borealis Bong. is relatively easy and can be done by home gardeners with some basic gardening skills.
Disease and Pest Management for Achillea borealis Bong.
Achillea borealis Bong., commonly known as boreal yarrow, is a hardy, perennial plant that is relatively resistant to most pests and diseases. However, in unfavorable conditions or when planted in crowded areas, it can be susceptible to several problems. Proper management techniques can help control these issues and keep the plant healthy.
Common Diseases
One of the most common diseases that can affect Achillea borealis Bong. is powdery mildew. This fungal disease appears as a white, powdery coating on the leaves, stems, and flowers of the plant. It is caused by inadequate air circulation, high humidity, and poor drainage. To prevent powdery mildew, avoid overcrowding the plants, ensure adequate space for airflow, and provide proper drainage. Also, prune the infected parts of the plant and remove any debris from around the plant to reduce the spread.
Achillea borealis Bong. can also be affected by rust, which is another fungal disease caused by Puccinia achilleae. Rust appears as small, yellow or orange spots on the underside of the leaves. The spots later turn brown and can cause premature leaf drop. To prevent rust, ensure that the plants are adequately spaced apart to promote airflow, remove and dispose of any infected leaves, and keep the foliage dry by watering at the base of the plant.
Common Pests
Achillea borealis Bong. is generally not a magnet for pests and is only occasionally attacked by small insects like aphids, spider mites, and thrips. These pests can cause stunted growth, yellowing of the leaves, and wilting of the plant. To control these pests, introduce beneficial insects like ladybugs, lacewings, and parasitic wasps that feed on the pests. Additionally, water the plant with a strong stream of water to dislodge and wash away the pests. Horticultural oils and insecticides specifically designed for these pests can also be used if the infestation is severe.
Keeping your Achillea borealis Bong. plant healthy requires regular monitoring and preventive measures. By following good cultural practices, properly spacing the plants, and applying the right management techniques, you can minimize pest and disease problems and keep the plant thriving for many years.
