Origin and Common Names
Erysimum capitatum (Dougl. ex Hook.) Greene, commonly known as western wallflower, is a member of the Brassicaceae family. It is native to western North America, specifically in areas ranging from Alaska to southern California and eastward to Montana, Wyoming, Nevada, and Colorado.Appearance
Western wallflower is a perennial herb that can grow up to 60 cm tall. It is characterized by its numerous, bright yellow, four-petaled flowers that bloom from May to July. The plant's leaves are lance-shaped, with a length ranging from 2 to 10 cm, and are hairy in texture. Its stem is stout and robust, with a reddish-brown color and grows from a basal rosette.Uses
Western wallflower has had traditional historical medicinal uses by Native American tribes for treating various ailments, including respiratory and digestive problems, as a blood purifier, and to alleviate headaches. The plant is also food for several wildlife species, including bighorn sheep, deer, elk, and mountain goats, making it an essential wild forage plant. Additionally, western wallflower has become popular for ornamental landscaping, as the plant can attract pollinators, and its beautiful flowers add bright colors to gardens and landscapes. Despite its beneficial properties, it is essential to contact a healthcare provider before using the plant for medicinal purposes, as excess consumption can cause negative side effects.Light Requirements
Erysimum capitatum plants require full sun to partial shade. They can tolerate full sun if the soil is kept consistently moist. However, in locations with hot, dry summers, plants may benefit from some afternoon shade.
Temperature Requirements
The ideal temperature range for Erysimum capitatum is between 68°F and 77°F (20°C - 25°C). However, they can tolerate temperatures as low as 50°F (10°C) and as high as 95°F (35°C). Plants may not flower well if temperatures consistently exceed 86°F (30°C).
Soil Requirements
Erysimum capitatum plants prefer well-drained, sandy, or loamy soil. They can tolerate slightly alkaline soil, but they prefer neutral to slightly acidic soil with a pH range of 6.0 to 7.5. Plants also require adequate soil moisture to thrive, but they can't tolerate soggy soil or standing water.
Cultivation
Erysimum capitatum (Dougl. ex Hook.) Greene, commonly known as Western Wallflower or Sanddune wallflower, is a herbaceous plant native to the western United States. It is a hardy and adaptable plant that grows well in a variety of soil types and environments.
When growing Erysimum capitatum, start by selecting a well-draining soil mix that is rich in organic matter. The plant prefers full sun to partial shade exposure and can tolerate various pH levels of soil. Plant the seeds or seedlings during the early spring or fall season. Space the plants at least 12 inches apart to allow for proper airflow and growth.
Watering Needs
Erysimum capitatum is a drought-tolerant plant that requires moderate watering. It is best to water the plant deeply once a week than to offer it frequent, shallow watering. Avoid overwatering the plant as it can lead to root rot and other water-related problems. During the hot summer weather, the plant may require more frequent watering to prevent wilting.
Fertilizing
Erysimum capitatum does not require heavy fertilization; instead, it thrives in nutrient-rich soil. Add organic matter such as compost to the soil in the early spring to promote growth. A slow-release fertilizer applied at the beginning of the growing season will sustain the plant throughout its development. Use a well balanced, all-purpose granular fertilizer that contains nitrogen, phosphorus, and potassium.
Pruning
Deadheading or pruning the plant can encourage bushier growth and prevent it from becoming leggy. Cut back the spent flower spikes to encourage the plant to produce more flowers. It is best to prune the plant during its active growth period to promote bushy growth and maximize flowering. Cut back the plant to the nearest leaf node to encourage dense growth and more blossoms.
Propagation of Erysimum capitatum
Erysimum capitatum (Dougl. ex Hook.) Greene, commonly known as western wallflower, is a popular ornamental plant that belongs to the Brassicaceae family. It is a short-lived perennial plant that can be propagated by using various methods.
Propagation by Seed
The easiest way to propagate Erysimum capitatum is by using seeds. Collect the seeds from the parent plant after they have dried on the stem. Sow the seeds in the soil during the late summer or early fall, or in the late spring before the time of flowering. Cover the seeds lightly with soil and keep them moist. The seeds will germinate within two weeks to a month. The seedlings can then be transplanted into individual pots or directly into the garden.
Propagation by Cuttings
Erysimum capitatum can also be propagated by stem cuttings. Take the cuttings from the parent plant during the late spring or early summer when the plant is in its growing season. Choose a vigorous stem with no flowers or buds. Cut the stem at a 45-degree angle and remove the leaves from the lower half of the stem. Dip the cuttings in rooting hormone and plant them in rooting medium. Keep the soil consistently moist and place the cuttings in a warm, bright location. The cuttings will root within several weeks.
Propagation by Division
Erysimum capitatum can also be propagated by division. Dig up the parent plant during the spring or fall and pull apart the clumps into smaller sections. Each section should have several shoots and a portion of the roots. Replant the divided sections in the soil and water them thoroughly. Keep the soil consistently moist until the plant is established.
Disease and Pest Management for Erysimum capitatum
Erysimum capitatum (Dougl. ex Hook.) Greene is a beautiful plant species with a bright, attractive yellow flower that makes it a popular choice among gardeners. However, like other plants, it is prone to disease and pest attacks that can damage its growth, reduce yield, and even lead to plant death. It is therefore necessary to be aware of common pests and diseases that could affect the plant and take steps to manage them.
Common Diseases of Erysimum capitatum and their Management
1. Powdery Mildew: Powdery mildew can occur when humidity levels are high, and temperatures are cool. It appears as a white powdery growth on the leaves of the plant, causing them to yellow and wilt. To manage powdery mildew, it is important to keep the foliage dry by watering the plants at the base and not using overhead watering. It is also beneficial to remove affected leaves and applying fungicides containing copper.
2. Verticillium Wilt: This disease affects the vascular system of the plant, causing the leaves to wilt and yellow. The fungus that causes this disease survives in the soil and can affect the plant for several years. Management involves removing and destroying affected plants, keeping the soil healthy, and planting disease-resistant plants.
3. Clubroot: Clubroot is a soil-borne disease that causes the roots to swell, become soft, and form galls. The infected plants may also become stunted and turn yellow. Management includes removing and destroying infected plants, rotating crops, and planting clubroot-resistant plants.
Common Pests of Erysimum capitatum and their Management
1. Aphids: Aphids are small, soft-bodied insects that suck sap from the leaves and flowers of the plant, causing them to wilt and deform. Management involves using insecticidal soaps, horticultural oils or natural predators such as ladybugs to control their population.
2. Cabbage Loopers: These are caterpillars that feed on the leaves of the plant, causing large holes and significant damage. Management includes picking them off by hand or using Bacillus thuringiensis (BT), a bacteria that kills the caterpillars, to control their population.
3. Slugs: Slugs are nocturnal pests that feed on the plant leaves, causing significant damage. Management includes using physical barriers such as copper tape or spraying iron phosphate-based baits that are safe for the environment.
By monitoring Erysimum capitatum for signs of pest and disease attack, and promptly employing appropriate management measures, it is possible to keep the plant healthy and productive throughout the growing season.
