Bidens are prolific flowering plants with yellow or orange daisy-like blooms; newer biden varieties have pink, gold, and white blossoms. They are also commonly called Spanish needles, tickseed sunflowers, and beggarticks. They thrive in rich soil with sufficient drainage and require full sun. They tolerate drought and heat relatively well. Bidens are perennial plants in warmer climates. In northern climates with freezing temperatures, they are annuals and will need replanting each year.
|Common Name||Bidens, beggarticks, black-jack, burr marigolds, cobbler's pegs, Spanish needles, stickseeds, tickseeds, and tickseed sunflowers|
|Botanical Name||Bidens spp.|
|Plant Type||Annual, perennial|
|Mature Size||6-12 in. tall, 1-3 ft. wide|
|Soil pH||Slightly acidic to neutral|
|Flower Color||Yellow, gold, white, pink, orange|
|Native Area||North America, South America, Africa, Europe, Asia|
Here are the main care requirements for growing bidens:
- Plant in rich soil with good drainage.
- Grows best in neutral to slightly acidic soil.
- Requires full sun.
- Will not require deadheading to produce new blooms.
- Feed monthly with a general-purpose fertilizer.
Several Bidens species are invasive in the U.S. and other parts of the world, including Bidens pilosa (40 countries, including Hawaii), Bidens cernua (Alaska), Bidens aristosa (Maryland, Delaware, Kentucky), and Bidens frondosa (Alaska).
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 daily. Without adequate light, the plant will still grow but may not produce as many blooms and is likely to be leggy.
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 various pH levels in soil but generally does best in neutral to slightly acidic soil types.
These plants are considered reasonably 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
This plant tolerates high heat and drought. Many of these plants grow in warm and humid locations like Hawaii, Mexico, and Polynesia. This plant's drought-resistant quality also helps it 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 below 40 degrees Fahrenheit.
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 every month or to use a timed-release fertilizer when planting. Fertilizer is especially important if you are growing bidens in a container. They may need more nutrients as potted plants since nutrients drain away.
Types of Bidens
There are more than 200 species of bidens with native varieties in Hawaii, Mexico, and Europe. In the United States, bidens have 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. It's a native of Mexico and is also called the Apache beggartick or fern-leaved beggartick, courtesy of its fine, soft foliage.
Bidens are easy to maintain. They don’t need to be pruned or deadheaded. However, if it becomes too large, you might prune the plant back in favorable growing conditions. Also, pinching or cutting back the plant can make it denser and encourage new blooms.
It's relatively easy to propagate this plant by seed, cuttings, or division. Cuttings and division extend the lifespan of the plant. It is best to take cuttings and divide bidens in the spring.
Here's how to propagate by cuttings:
- You'll need sterilized scissors or pruning snips to cut off an actively growing 3- to 4-inch stem with at least one node. Leave a couple of the larger leaves in place. Cut off smaller plant growth, flowers, or buds.
- You'll also need a container of moist potting soil and, optionally, rooting hormone.
- Dip the cut end in rooting hormone, and plant the stem about two inches deep into the soil. Keep the soil moist.
- New growth should occur within three to six weeks.
To divide a bidens plant:
- You'll need a shovel to dig around and under the plant's root ball.
- Use a saw or shovel edge to cut the ball into halves, thirds, or quarters, depending on the size of the plant you have and the size of the plant you want to transplant.
- Replant in the ground or in containers with moistened potting soil. Put the plant in a full-sun location.
How to Grow Bidens From Seed
To propagate by seed, sow the seeds at the end of winter or the beginning of spring. If direct sowing outdoors, wait until after the last frost when temperatures reach at least the 60s.
- Surface sow seeds, only pressing them into the soil. Keep the soil moist.
- Place your seed tray in a sunny location and maintain a temperature of at least 65 degrees Fahrenheit.
- Germination takes about 7 to 20 days.
Potting and Repotting Bidens
Bidens make good potted plants. After several years bidens lose their vibrancy and vigor, which is a sign they may need dividing or repotting if they have outgrown their container. You'll know it's rootbound if water pools at the top of the soil, no longer draining, or roots start growing out of the drainage holes.
Get another same-size pot, divide the root ball in half, and replant each half in each of the pots in moistened soil. This plant may need dividing and repotting every two to three years.
Bidens will die in the winter if temperatures drop below 40 degrees Fahrenheit. They are an annual in frosty regions and must be planted again in the spring.
In zones 8-11, it will grow as a perennial. It will lose its blooms in late fall and winter, but its beautiful foliage remains green all year. Expect the flowers to return 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
You do not have to do anything special to keep Bidens blooming; bidens bloom prolifically. In regions with winters that stay above freezing, it is natural for bidens to stop flowering in fall and winter but keep their green foliage. They'll bloom again when the weather warms up.
There's no need to deadhead bidens to increase the blooms. However, ensure they are in good soil, with rich fertilizer and plenty of water for bidens to grow at their best.
Bidens typically bloom from May to October.
How Long Does Bidens Bloom?
Blooms usually last about two to three weeks. They rebloom continuously, returning annually (within zones 8-11).
What Does Bidens Flowers Look and Smell Like?
Bidens have a slightly sweet scent favored by bees for their nectar and pollen. They are related to daisies and look much like them with delicately petalled, star-shaped flower heads.
How to Encourage More Blooms
This continuous bloomer doesn't need encouragement; it reblooms as soon as its old flowers wither. However, pruning brings bushier growth, likely producing more flowers. Give fertilizer monthly to keep this plant's flower production vigorous. Also, make sure this plant has full sun for full bloom potential.
Common Problems With Bidens
Growing virtually all types of bidens is relatively easy. It's natural for the plant to die off in the winter if temperatures fall below freezing.
Bidens not grown in full sun tend to get leggy as they extend their stems looking for more sunlight. They also don't bloom as much and look unappealing.
Can bidens grow indoors?
While bidens are popular for gardens and landscaping, they also make an excellent choice for container gardening. The abundant foliage and flowers are well-suited to flower boxes or hanging planters. Much of the care of bidens grown in containers remains the same; however, it will be important to fertilize these plants since they require rich soil for flowering and overall vitality.
How long will bidens live?
In areas where the temperatures drop below 40 degrees Fahrenheit, bidens will die in the winter, not living longer than a year. However, depending on the species, they can live in warmer areas for 3 to 10 years.
Where should I place bidens in my house?
If you're going to grow bidens in a container garden in your home, make sure it gets direct, full sunlight. A sunny windowsill will work wonders for this plant. Bdens are considered an excellent choice for a spiller plant.
Bidens pilosa. Global Invasive Species Database.
Nodding beggarticks (Bidens cernua). Invasive Plant Atlas of the United States.
Bidens aristosa. Smithsonian Environmental Research Center.
Devils beggarticks. Invasive Plant Atlas of the United States.