How to Plant and Grow Bidens

Tumbling over the edges of containers and spilling down the sides of hanging baskets, bidens look like a colorful floral waterfall. These annuals (or short-lived perennials in zones 8-11) have prolific blooms of orange, gold, pink, white, or red. Their fine foliage adds a light, airy texture and acts as an unobtrusive backdrop to let the floral display shine.

The bidens plant started with simple yellow blooms, but it's now available in various colors. Most commonly grown as a trailing or groundcover plant, bidens are also available in more upright types that work as a bedding plant. This tough annual can keep blooming through some genuinely rough conditions.

Where to Plant Bidens

For the best blooms, plant bidens in full sun in well-drained soils with a good amount of organic matter and slightly acidic pH (5.5 to 6.3) While the plants can tolerate part sun, they won't bloom as well when they lack sunlight, and the overall plant habit can become leggy and unappealing. 

Bidens are a good pick for containers, hanging plants, and planter boxes because of their abundant flowers.

How and When to Plant Bidens

The bidens commonly sold by nurseries are frost-sensitive, and the plants die below 40 degrees F. Delay planting until after the last average frost date in your location.

Dig a hole about twice the diameter of the nursery container. Plant bidens about 10 to 15 inches apart to allow for good air circulation.

Bidens Care Tips

There has been a recent influx of new bidens varieties featuring new colors, patterns, and habits. Bidens plants used to be mainly oranges and yellows but now include pinks and whites. Another improvement for bidens has been plant habits. Some older types can get leggy and loose, so many new varieties have improved branching with tighter internodes, which means denser plants and more blooms. Most new types are also sterile, so the plants don't waste energy on seed production and produce more blooms for extended periods.

Light

Bidens should get at least six hours a day of full sunlight.

Soil and Water

Plant in fertile, well-drained soil with a pH between 5.5 and 6.3. Once established, bidens are quite drought-tolerant, but a too-long period of drought can affect their blooming potential, so water them about once a week for an extended bloom.

Temperature and Humidity

The temperature tolerance depends on the variety. Most bidens sold in the nursery trade do fine with hot and humid temperatures but will die back when it dips below 40 degrees F. Other varieties of bidens are winter-hardy even in cold climates.

Fertilizer

Give them a monthly dose of fertilizer at a minimum to keep them producing cheery flowers or at least a dose of slow-release fertilizer at the start of the growing season. For the amount to use, follow product label instructions.

Pruning

Because these plants can be a little rangy at times, it's a good idea to give bidens plants a good pinching or shearing early on to encourage dense plants with lots of branching. If plants become leggy during the season, they can handle a hard cutback to encourage a new flush of foliage and flowers. Bidens don't require deadheading; because of their rapid growth and numerous flowers, they "bury their dead." When the old blooms drop their petals, there is already a flush of new growth to cover it up.

Potting and Repotting Bidens

Bidens make good potted plants. Use a pot with large drainage holes, preferably terra-cotta, to wick away excess moisture. Fill it with a well-draining potting mix. For a single plant, the pot should be at least 6 inches in diameter. Potted plants need more frequent watering and fertilizer than inground plants due to the loss of nutrients through drainage.

Since bidens are mostly grown as annuals and their life cycle ends with the onset of fall frost, repotting them is usually unnecessary because they don’t outgrow their pots in a single season. If you live in a warm climate where bidens is a short-lived perennial, repot the plant to a larger container when the roots have filled the container or grow out of the drainage holes.

Pests and Problems

Some older varieties of bidens can produce burr-like, bothersome seeds, as they stick to anything and everything. Bidens hitch rides on animals and other passersby to spread their seeds, which can be aggravating in a garden setting, especially with pets. Fortunately, many new varieties are sterile, with no sticky seeds to worry about.

Whiteflies may be a problem for bidens, and botrytis and pythium are diseases that can afflict plants.

How to Propagate Bidens

The best way to propagate bidens is through seeds. Start the seeds indoors about six weeks before the last frost date to get a head start on the season. Use seed flats or small pots filled with sterile, damp potting mix. Place the seeds on top and gently press them into the soil, but do not cover them as they need light to germinate. Keep the pots well-watered in a warm, bright location, ideally under grow lights. Harden off the seedlings before transplanting them outside in garden beds or containers after the last frost.

Types of Bidens

'Goldilocks Rocks' Bidens

Bidens ferulifolia 'Goldilocks Rocks' has large, semi-double golden blooms. The vigorous drought-tolerant plants are perfect for containers. Zones 9-11

'Bee Alive' Bidens

Bidens ferufolia ‘Bee Alive’ has a mounding growth habit, which makes it an excellent choice for containers and hanging baskets. It is covered in large orange-red flowers from spring through fall. Zone 9-11

Tall Swamp Marigold

Tall swamp marigold (Bidens coronata), also known as crowned beggarticks, is a winter-hardy bidens variety with a spreading habit and large yellow flowers. Zones 3-8

Bidens Companion Plants

Angelonia

Angelonia is also called summer snapdragon. It has salvia-like flower spires that reach 1 or 2 feet high, studded with snapdragon-like flowers with beautiful colorations in purple, white, or pink. It's the perfect plant for adding bright color to hot, sunny spaces. This tough plant blooms all summer long with spirelike spikes of blooms. Keep an eye out for the sweetly scented selections. While most gardeners treat angelonia as an annual, it's a tough perennial in its hardy Zones. Or, if you have a bright, sunny spot indoors, you can keep it flowering all winter. Zones 9-10

Geranium

Geraniums have been a gardener's favorite for well over a century. The old-fashioned standard for beds, borders, and containers, geranium is still one of the most popular plants today. Traditional bedding types love hot weather and hold up well to dry conditions; many offer colorful foliage.

Though most geraniums are grown as annuals, they are perennials in their hardy Zones. If you like, bring them indoors to overwinter, then replant outdoors in spring. Or they can bloom indoors all year long if they get enough light. Zones 10-11

Garden Plans for Bidens

Deckside Container-Garden Plan

Dress up your deck with this low-maintenance, high-color container-garden plan.