You won’t need to deadhead the plant for it to continue blooming during its long flowering season of May to October. The prolific plant continuously produces new foliage to cover dying blooms, and new flowers quickly take their place. In the winter, the plant will die off if temperatures fall below freezing. In zones 8-11, it will grow as a perennial. Popular in both gardens and containers, bidens are considered an excellent choice as a groundcover or spiller plant. Newer varieties also offer more upright choices.
Light
Bidens prefer full sun conditions for the biggest and best blooms. Any location you choose to plant bidens should receive at least six hours of direct sunlight per day. Without adequate light, the plant will still grow but may not produce as many blooms and is likely to be leggy.
Soil
Whether you’re planting bidens in an outdoor garden or a container, ensure that they have well-drained soil to avoid problems with root rot. In addition, this abundantly blooming plant thrives in rich, humus soil. It can tolerate a variety of pH levels in soil but generally does best in neutral to slightly acidic soil types.
Water
These plants are considered fairly drought-resistant. However, they do require regular watering for their best appearance and longevity. An inch of water per week is typically sufficient; water before wilting begins.
Temperature and Humidity
Warm temperatures don’t put a damper on the growth and blooming of most varieties of bidens. With many of these plants being native to warm-weather locales like Hawaii, Mexico, and Polynesia, it’s safe to say that they won’t mind a little heat and humidity. The drought-resistant quality of this plant also helps it to endure hot, dry conditions. However, if such a spell of dry weather persists, it’s best to provide these plants with regular watering to offset the impact of the heat on the plant’s foliage and blooms. On the other hand, if temperatures dip too low, bidens plants will suffer. These plants are not frost-resistant and will die at temperatures under 40 degrees Fahrenheit.
Fertilizer
To flourish, the abundantly flowering bidens plant will require nutrient-rich soil. How much fertilizer to use and what type is generally specified by the specific type of bidens plant you’re growing. It’s generally recommended to supplement this plant with a general-purpose fertilizer or to use a timed-release fertilizer when planting. Fertilizer is especially important if you are growing bidens in a container.
Types of Bidens
There are more than 200 species of bidens plants with native types in such far-flung places as Hawaii, Mexico, and Europe. In the United States, these plants are considered native species in every state except Wyoming. If you encounter wild-growing bidens, you’ll recognize them for the tiny, sticky seeds that cling to your clothing or in your dog’s fur. The good news is that most commercially available bidens have been cultivated to avoid the sticky seed problem. Here are a few:
Bidens alba: Resembling a daisy, this bidens plant variety features white petals and a bright yellow center. It’s also sometimes referred to as beggarticks or Spanish needles. Bidens ‘Campfire Burst’: This variety of bidens is hard to miss, thanks to the brightly-hued flowers crowning each plant. The tri-colored petals are shaded inward from a deep red to blazing orange and zippy yellow. They flower abundantly from the summer into the fall and are a great colorful addition to any landscape design.Bidens ferulifolia ‘Golden Nugget’: With yellow petals that resemble a star and an orange center, the Golden Nugget variety is one of the most eye-catching bidens plants. It’s a native of Mexico and is also called the Apache beggartick or fern-leaved beggartick, courtesy of its fine, soft foliage.
Pruning
Bidens are easy to maintain and don’t need to be pruned or deadheaded. However, in favorable growing conditions, you might choose to prune the plant back if it becomes too large. Also, pinching or cutting back the plant can make it denser and encourage new blooms.
Propagating Bidens
It’s relatively easy to turn one bidens plant into many, since these plants can be propagated by seed, cuttings, or through dividing. If you want to propagate by cuttings, take an actively growing stem with a node from the plant. Plant it in moist, rich potting soil and water generously and often until new growth emerges. You can divide bidens plants to create more of these flowering beauties. For bidens growing as perennials in southern regions, wait to divide the plants until the spring.
How to Grow Bidens From Seed
To propagate by seed, you should plan to sow the seeds at the end of winter or the beginning of spring. Keep in mind that this plant prefers warm weather, so wait until after the last frost if you’re sowing seed in an outdoor location.
Overwintering
Bidens will die back in the winter if temperatures drop below 40 degrees Fahrenheit and will need to be planted again in the spring. In areas where the temperatures never get that low, expect them to bounce back in the spring. A 2-inch layer of mulch might help ensure they stay hearty.
Common Pests and Plant Diseases
Bidens might have issues with whiteflies, which can be remedied with earthworm castings sprayed at the base of the plant. Botrytis and pythium are common diseases that might affect bidens plants. The cure is often the use of a broad-spectrum fungicide.
How to Get Bidens to Bloom
Bidens are very hearty plants that want to bloom prolifically. There’s no need to deadhead them to increase the blooms, but ensuring they are in good soil, with rich fertilizer and plenty of water, as essential steps to ensuring bidens plants grow at their best.
