Named for the vivid red color of a Roman Catholic cardinal's robe, the cardinal flower (Lobelia cardinalis) produces intense red blossoms at a time when many other perennials are declining in the summer heat. This plant is an excellent choice for naturalizing and wildflower meadows, but you'll also enjoy growing cardinal flowers in perennial borders. So exactly what is a cardinal flower and how do you grow cardinal flowers in the garden? Keep reading to learn more about the cardinal wildflower plant.
What is a Cardinal Flower?
The cardinal wildflower plant is an American wildflower native to Illinois, Indiana, Iowa, Michigan, Missouri, Ohio, and Wisconsin. These Lobelia flowers are tall perennials that thrive in USDA plant hardiness zones 1 through 10. Tall spikes of brilliant red, trumpet-shaped flowers rise above the dark green foliage. Growing cardinal flowers bloom during summer and sometimes into fall.
Most insects struggle to navigate the long necks of the trumpet-shaped flowers, so cardinal flowers depend on hummingbirds for fertilization. The bright red color of the flowers and the sweet nectar attract many species of hummingbirds and growing cardinal flowers are ideal for use in hummingbird gardens.
The finely ground roots of this Native American wildflower were once traditionally used as aphrodisiacs and love potions, but the plant is toxic if eaten in large quantities. Therefore, it is better to stick only to growing and caring for cardinal flowers as opposed to using them medicinally.
How Do You Grow Cardinal Flowers?
Cardinal flowers grow best in a location with morning sun and afternoon shade, except in cool areas where they need full sun.
They need a moist, fertile soil and perform best if you work plenty of organic matter into the soil before planting. Set out new plants in spring, spacing them about a foot apart. Keep the soil very moist as the seedlings become established. A layer of organic mulch around the plants will help prevent water evaporation.
Caring for Cardinal Flowers
•Water your growing cardinal flowers deeply in the absence of rain.
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•Fertilize the plants in fall with a shovelful of compost for each plant or a general purpose fertilizer.
•In USDAzones colder than zone 6, cover the plants in fall with a thick layer of pine mulch unless you expect heavy snow cover.
Cardinal flowers begin blooming in early summer and peak in mid- to late summer. Clip out the flower stems when they are done blooming, or leave them in place if you want the plants to self-sow. You'll have to pull back the mulch so the seeds can fall directly onto the soil if you want seedlings. If you cut the spent flower spikes just above the leafy part of the stem, new spikes may arise to take their place, but they will be somewhat shorter than the first spike.
FAQs
Cardinal flowers grow best in a location with morning sun and afternoon shade, except in cool areas where they need full sun. They need a moist, fertile soil and perform best if you work plenty of organic matter into the soil before planting. Set out new plants in spring, spacing them about a foot apart.
How does cardinal flower grow? ›
It is a fairly fast-growing plant that requires full to partial sun. Individual plants are short-lived, but cardinal flower perpetuates itself constantly by self-seeding and sending out offshoots that quickly colonize an area.
Where is the best place to plant cardinal flowers? ›
Hardy in Zones 3 to 9, cardinal flowers can be found on roadsides and the banks of ponds, streams and rivers. They also grow in swamps and wet ditches, meadows and woodlands. Unlike many plants that rot in wet soil, they need evenly moist soil.
Does cardinal flower need fertilizer? ›
Cardinal flower will take two years to bloom, forming a large rosette the first year. Allow the plants to self-sow. They are heavy feeders, so compost or a shot of granular fertilizer when they begin growth is recommended.
How to take care of cardinal flowers? ›
Cardinal flowers grow best in a location with morning sun and afternoon shade, except in cool areas where they need full sun. They need a moist, fertile soil and perform best if you work plenty of organic matter into the soil before planting. Set out new plants in spring, spacing them about a foot apart.
Do cardinal flowers come back every year? ›
Once established in your garden, Cardinal flower will self-sow and come up for years. Lobelia is perennial, but is considered a short-lived plant, so natural reseeding is important to keep the population healthy and abundant. It grows well in any garden if it does not dry out.
What do cardinal flowers need? ›
Cardinal flowers can be grown in full sun or very light shade but probably grow best in filtered light. The roots require moisture so mulch is needed, or it can be planted on the edge of a marsh or pond.
What is the Cardinals favorite plant? ›
Native trees and shrubs are always a good bet when you want to attract local birds. Some of the cardinals' favorite trees include mulberry, serviceberry, flowering dogwood, crabapple, and spruce. Shrubs at the top of their feeding list include staghorn sumac, red-osier dogwood, gray dogwood, and viburnum species.
How tall does a cardinal flower grow? ›
Cardinal flower produces leafy inflorescences 3-6 feet tall from midsummer to fall. The flowers are a brilliant red. Each erect terminal raceme is covered with numerous five-lobed flowers. The flowers open from the bottom to the top over a period of several weeks.
How much water does the cardinal flower need? ›
Cardinal Flower needs 0.8 cups of water every 9 days when it doesn't get direct sunlight and is potted in a 5.0" pot. Use our water calculator to personalize watering recommendations to your environment or download Greg for more advanced recommendations for all of your plants.
The Cardinal Flower is named for its thrillingly cardinal-red flowers. For attracting hummingbirds, the Cardinal Flower gets our bird-friendly seal of approval because it is an excellent source of nectar for Ruby-throated Hummingbirds mid-August through October.
How to keep Lobelia blooming all summer? ›
To have the most blooms, it's necessary to pinch or prune lobelia back to keep it bushy, which will lead to continual flowering. Once flowers fade, prune them off and new buds will appear. Fertilize monthly. Feed lobelia on a regular basis with an organic fertilizer designed for flowering plants.
Is cardinal flower toxic to dogs? ›
Although these beautiful red perennials have been used for medicine, the cardinal flower is actually very toxic to people as well as dogs and other animals. It is common to see the cardinal flower growing anywhere in the United States and Canada along the banks of streams and rivers as well as in gardens.
Is cardinal flower invasive? ›
Special characteristics: non-aggressive. non-invasive. native to North America - Wet places in eastern North America.
What is the host plant for the cardinal flower? ›
In addition to being stunningly beautiful and a hummingbird magnet, lobelia cardinalis (the straight species) is an important host plant for many native butterflies and moths, including the spicebush swallowtail, and others (see links to the right).
Does red cardinal flower spread? ›
The cardinal flower's natural range is New Brunswick, Quebec, and Ontario southward to Florida and Texas and across the southern plains and mountain states to California.
Do cardinal plants spread? ›
Plants are 2-4' tall with a 1-2' spread.
