Numerous types of Bidens species can be found thriving in their natural environment, while others have spread beyond their original range. While some species are known for their aggressive growth habit, others are commonly cultivated in garden and landscape settings. To avoid confusion about the different types of Bidens, let’s delve into their cultivation and history. As members of the Asteraceae family, Bidens are typically annual or short-lived perennial plants. Currently, there are around 220 recognized species of Bidens in existence.
Bidens are flowers with petals similar to daisies and yellow tubular disk florets. The length and presence of petals vary depending on the species, and some don’t have petals at all. The foliage is green and the leaf structure changes between species. Bidens are found all over the world, from Africa to Europe, Central and South America, and Asia. They grow best in warm, tropical areas, but can also be grown as annuals in colder regions. In some zones, they can survive as perennials for a short period. The name of the genus comes from the Latin words “bis” and “dens,” which mean two and tooth respectively. This refers to the fruiting head’s two sharp pappi or modified calyxes at the tip that look like “two teeth.”
The various popular names associated with Bidens can cause a mix-up between different species. Some of the commonly used names are Beggarticks, black jack, burr marigolds, cobbler’s pegs, Spanish needles, stickseeds, tickseeds, and tickseed sunflowers. These names pertain to the way the plant grows or the look of the seed heads. My introduction to this tough and bee-friendly flower was through B. ferulifolia, which appeared like miniature sunflowers.
B. ferulifolia is a sturdy plant that thrives in hot conditions and is commonly found growing naturally in the American Southwest and Mexico. Many of the ornamental plants available on the market today have been specifically cultivated from this resilient species.
Native to tropical and subtropical regions of the Americas, B. pilosa, also known as Spanish needles, has spread throughout the world and is often used for food and alternative medicine purposes. Despite being viewed as a noxious weed by some, others choose to grow it in their gardens. However, this species is considered an agricultural and environmental nuisance in over 40 countries and poses a threat to 31 major crops.
B. pilosa and B. alba are frequently mistaken for one another due to their shared common name and tendency to become invasive in specific regions where they have been introduced. While B. alba is used for its nutritional and medicinal properties, it can also be challenging to distinguish between the two species. Nonetheless, the length of their white petals is a straightforward way to differentiate between them since B. alba’s petals are longer.
B. Pilosa and B. Alba are known to thrive in various locations, but endemic species in Hawaii are at risk due to factors such as land development and competition from invasive plants. For instance, the Ko`oko`olau, a subspecies of B. Micrantha or ctenophylla is considered endangered in Hawaii. To counteract this loss, landowners are encouraged to cultivate and protect threatened species. It could be fascinating to understand a plant’s historical origin even if we decide to opt for non-native species. Moreover, it can be thrilling to spot a native plant while exploring the wild. If you’re an avid gardener, there is an extensive range of native species within the genus to explore and learn about.
Apart from native species, there are cultivars of plants with more attractive blooms that offer a wide range of planting options suitable for various garden designs. If you want to grow Bidens in your garden, it is effortless to propagate them from seed or cuttings. However, the availability of its seeds may not be as widespread as nursery starts. Therefore, you can either save seed from existing plants or search for seed suppliers online. Transplanting seedlings or nursery starts into your garden or larger containers is also simple, provided you plant them in conditions that allow them to thrive. To sow Bidens seeds, it’s best to start them indoors in a heated area as they prefer warm weather. If you plan to sow them outside, make sure to wait until after the last frost and when soil temperatures have increased.
To start seeds, simply sow them on the surface of a moist seed-starting mix and gently press them into the soil. To ensure germination, keep the seed tray in a sunny location indoors with a temperature of at least 65°F. If you prefer to sow directly outdoors, wait until after the last frost when temperatures reach the high 60s. Make sure to keep the soil evenly moist and your seeds should sprout within one to three weeks.
For propagating Bidens, taking cuttings is a great method to extend their lifespan and increase your garden’s plant supply. Choose a branch that hasn’t flowered or remove any flowers and buds. Leave only the larger leaves intact and cut off any new smaller ones. Using a low-strength rooting hormone can speed up root development, which typically takes three to six weeks. Dip the cutting into the hormone while wearing gloves and shake off any excess before planting it at least two inches deep into a container of moist potting soil. Keep the soil consistently moist.
To transplant seedlings or nursery starts, wait for spring when the weather has warmed up and there is no threat of frost.
For optimum root health, make sure to water your plants regularly. In case your plants are not flowering, it might be due to lack of sunlight or water. When growing plants like B. pilosa for medicinal purposes, you don’t need to worry about planting them in soil rich in organic matter as these plants grow well in lean and disturbed soil.
To ensure healthy growth, use nutrient-rich soil and ensure good drainage. While planting, make sure to choose an area that receives full sun or at least four hours of sunlight in shaded locations. During hot weather, provide extra water to encourage more blooms.
Bidens bloom profusely from May to October, and you don’t need to deadhead them as they take care of their flowering needs. If you want fuller and bushier plants, occasionally pinch them back to promote branching growth. During summers, if temperatures rise, give them extra water as they reward with more blooms.
It’s important to keep in mind that if you don’t want
B. alba
to dominate other areas of growth, you should control its aggressive reseeding. On the other hand, the cultivar
B. ferulifolia
, known as bɩazing fire, has a name that perfectly describes its appearance. Its vivid flowers resemble flames and bloom from late spring to mid-fall, with dark red buds adding to its stunning display.
This type of plant is very strong and can survive with minimal watering, making it perfect for areas that experience drought. Known as ‘blazing fire’, it’s a great addition to planting arrangements as it adds a fiery element to combinations with other plants. Another option for adding some brightness to your garden is ‘Gold Nuggets’, whose double daisy-like flowers stand out against the green foliage when grown in borders, containers, or hanging baskets. Yellow is a joyful color, and this plant is sure to bring a smile to your face.
The plant variety ‘Golden Nuggets’ is highly attractive to pollinators and blooms from midsummer to fall. Burpee offers seeds of this variety in packages of 50. When it comes to pests and diseases, Bidens are generally resilient and experience few issues. However, there are a few concerns to keep in mind. Two common insects that can affect the growth of Bidens are aphids and whiteflies. Aphids suck the sap from plants and can spread disease, but they can be controlled by attracting beneficial insects like ladybugs, green lacewings, and birds to the garden. Whiteflies, on the other hand, might cause leaves to yellow, shrivel, and drop prematurely, but they can be managed by encouraging the presence of beneficial insects such as ladybugs, green lacewing larvae, spiders, and dragonflies. As for diseases, plants grown in optimal conditions are less vulnerable, but stressed plants can become susceptible to diseases that may lead to plant death. Bidens Mottle virus and Botrytis Blight are two common diseases that might affect Bidens. Pythium Root rot can be a persistent issue in waterlogged soils with poor drainage. Good garden maintenance, cleaning containers before planting, relying on trusted soil sources, ensuring good soil drainage, and being mindful not to overwater are some preventive measures one could take. Bidens serve as great planting options for planters, hanging baskets, and garden beds as borders.
These plants can be a great addition to your drought-tolerant and pollinator-friendly garden designs. They may even help cultivate threatened species, increasing their population. The Quick Reference Growing Guide provides information about the plant type, flower and foliage color, native regions, tolerances, hardiness, maintenance, season, soil type, exposure, spacing, soil pH, drainage, planting depth, attracting qualities, height, spread, water needs, family, common pests, diseases, and species. Bidens are short-lived perennials or annuals that come in red, orange, peach, pink, yellow, white, and green colors. They are native to Africa, Asia, Central America, Europe, North America, and South America. They can tolerate drought and heat and thrive well in full sun to partial shade. They require low maintenance and grow well in fertile soil with good drainage. Bidens can attract bees, butterflies, hummingbirds, and moths and come in different heights ranging from 6 inches to 5 feet, depending on the variety. They are commonly used for hanging baskets, plant combinations, pollinator gardens, borders, and xeriscaping. Bidens’ water needs are low and are typically established once they’ve started growing. Common pests and diseases include aphids, whiteflies, mottle virus, Botrytis blight, and Pythium root rot. Plant Bidens in the spring for beautiful and fragrant flowers that will attract pollinators throughout the fall.
The abundant foliage and frequent blossoming of various types may inspire you to cultivate more than one species! For those who prioritize establishing flourishing garden ecosystems, give Bidens a chance. These plants play a crucial role in promoting thriving habitats for local wildlife. If you’re particularly fond of these flowers that attract bees, butterflies, and hummingbirds to your garden, you can learn more about how to attract pollinators here.
