Purple viper’s bugloss (Echium plantagineum) is native to parts of Europe, Asia, and Africa, but it has also been naturalized in Australia and the Americas, where it is sometimes considered a noxious weed. The plant produces vibrant bluish-purple flowers that are an important early nectar source for bees; however, purple viper’s bugloss is highly poisonous to grazing livestock, particularly horses.
I. Appearance and CharacteristicsÂ
Echium plantagineum, commonly known as purple viper’s-bugloss or Patterson’s curse, is a species of the genus Echium native to western and southern Europe (from southern England south to Iberia and east to the Crimea), northern Africa, and southwestern Asia (east to Georgia). It has also been introduced to Australia, South Africa, and United States, where it is an invasive weed. Due to a high concentration of pyrrolizidine alkaloids, it is poisonous to grazing livestock, especially those with simple digestive systems, such as horses.
The Latin genus name comes from the Greek word ekhis, which means viper (a type of snake), possibly due to the seeds resembling a viper’s head or the forking at the end of the thin flower style resembles a viper’s tongue. The plant roots when eaten with wine, are claimed to provide a folk cure for a snakebite. The Latin specific epithet plantagineum refers to the leaves of the plant, which are similar to those of a plantain.
Echium plantagineum is a winter annual plant growing to 20–60 cm tall, with rough, hairy, lanceolate leaves up to 14 cm long. The flowers are purple, 15–20 mm long, with all the stamens protruding, and borne on a branched spike.
Toxicity
E. plantagineum contains pyrrolizidine alkaloids, so is poisonous to nonruminants. When eaten in large quantities, it causes reduced livestock weight, and death in severe cases, due to liver damage. Paterson’s curse can also kill horses, and irritate the udders of dairy cows and the skin of humans. After the 2003 Canberra bushfires, a large bloom of the plant occurred on the burned land, and many horses became ill and died from grazing on it. Because the alkaloids can also be found in the nectar of Paterson’s curse, the honey made from it should be blended with other honeys to dilute the toxins.
Invasive species
E. plantagineum has become an invasive species in Australia, where it is also known as Salvation Jane (particularly in South Australia), blueweed, Lady Campbell weed, Paterson’s curse and Riverina bluebell.
In the United States, the species has become naturalised in parts of California, Oregon, and some eastern states and areas such as northern Michigan. In Oregon, it has been declared a noxious weed.
II. How to Grow and Care
Purple viper’s bugloss generally has a straightforward care profile. It thrives in well-draining soil and requires full sun exposure to flourish. One special care point to note is that purple viper’s bugloss is drought-tolerant once established, making regular watering less critical. However, it is essential to avoid waterlogging the roots as this can lead to decay. Maintain a regular, but moderate watering schedule to balance moisture levels.
Sunlight
Purple viper’s bugloss thrives in full sun conditions, where it can receive unfiltered, direct light for at least 6 hours daily. Though purple viper’s bugloss is adaptable to some variation in light exposure, prolonged periods outside its ideal range may hinder blooming and stunt growth. Purple viper’s bugloss demonstrates its resilience through certain adaptive traits, such as the capability to orient leaves towards light sources for maximum absorption.
Predominantly an outdoor plant, purple viper’s bugloss flourishes in open areas that provide ample sunlight, making it well-suited for beds, borders, and wildflower gardens. Ensuring that purple viper’s bugloss is planted where it can bask in full sun will greatly enhance its vitality and floral show.
Temperature
The purple viper’s bugloss is a very resilient plant. It is heat tolerant and can withstand temperatures down to -7 ℃. The purple viper’s bugloss needs regular water only for germination.
Watering
Originating from the Mediterranean, purple viper’s bugloss is adapted to a climate with moderate rainfall. This species thrives in conditions where it can experience a balance of moisture and dry periods, showcasing its ability to tolerate short droughts. In line with its natural rhythm, purple viper’s bugloss prefers watering every week to maintain its health and vigor. Given that purple viper’s bugloss is typically cultivated outdoors due to its robust nature, it’s important to consider the plant’s flowering phase when adjusting water supply; adequate hydration during this period is crucial for optimal bloom development.
Soil
The purple viper’s bugloss is not particularly picky about its soil type, just the drainage. It will grow best in sandy type soil, even if the soil is quite dry. Ideally, the soil should also have a bit of lime in it. The purple viper’s bugloss can tolerate alkaline, acid, and neutral soils, although its optimum pH is between 6-6.5.
Fertilizing
Fertilizing purple viper’s bugloss with balanced nutrition or high nitrogen fertilizers promotes robust growth and abundant blossoming. Apply a balanced 10-10-10 fertilizer in spring at the onset of growth. Increase nitrogen supply once buds form, roughly every 4-6 weeks. Use about 1 tablespoon per plant, ensuring even distribution at the base without direct stem contact. Seasonal changes trigger variable nutrient demands; reduce feeding in autumn. Use a lighter hand with new plants to avoid over-fertilizing. Always water thoroughly post-application. This targeted feeding schedule benefits both beginners and seasoned gardeners seeking vibrant purple viper’s bugloss displays.
Pruning
The purple viper’s bugloss does not need pruning, but you should pinch off wilted flowers in order to stimulate new blooms. The purple viper’s bugloss is so successful at spreading because it seeds readily – consider pinching off all flowers at the end of the flowering season, just before the production of the seeds starts. This will prevent it from spreading by seed.
Propagation
This perennial can rejuvenate its population through sowing. To achieve successful propagation, gardeners should use well-draining soil, ensuring it remains moist until germination. Given purple viper’s bugloss’s robust nature, the seeds tend to establish themselves readily when dispersed in a sunny location. Cover the lightweight seeds with a thin layer of soil to protect them from being washed away and to maintain the ideal conditions for sprouting. Be patient as the seedlings develop, and thin them out to prevent overcrowding and promote strong growth.
Transplanting
The perfect window to relocate purple viper’s bugloss falls between the generous warmth of late spring and the golden days of midsummer, promoting strong root establishment. Choose sun-drenched spots with well-draining soil, ensuring successful take. A friendly nudge: keep the roots intact during transfer for a happy, thriving purple viper’s bugloss.
III. Uses and BenefitsÂ
The versatile purple viper’s bugloss works as either an upright wildflower in garden beds or a drooping shrub in garden borders and hedges. The foliage is evergreen, while the showy summer flowers add ornamentation to gardens. It’s deer resistant and easily grows in sandy coastal gardens and well-drained cottage gardens. Bees will flock to this plant.
