Lobelia belongs to the bellflower family (Campanulaceae) and it consists of shrubs, annuals, and perennials. It is a low growing, widely popular, trailing or bushy flower. Most of the times, these flowering plant species are planted in garden beds or in containers because that is where they look the best. Keep in mind; it has the ability to litter the ground or the container. Although the typical and traditional shades of lobelia flowers would range from electric blue to violet, there are newer varieties that are available in red and pink as well. The stems of the lobelia flowers bear spikes of vibrant, tubular flowers.
The flowers and foliage of this plant are quite delicate. The lobelia flowers grow abundantly during the summer and frost time. During the spring and fall time, the flowers thrive under the full sun. However, during the summertime, the sun can be too strong for these delicate beauties, which is why putting them in shade is important. Bushy plants thrive in well-grouped beds, whereas the trailing ones do well in window boxes, hanging baskets, and containers.
The cultivation requirement of lobelia heavily depends on the species, but the majority of the species loves partial shade or the full sun and the soil must be well-drained and moist. This bellflower plant does not do well in drought as they are not tolerant. To add an aesthetic value to your house, the best thing to do would be to plant this beautiful looking flower plant in gardens or in outdoor containers. The beautiful shades of different colors can instantly add beauty to any setting.
Table of Contents
- Origin: Lobelia is a species native to most parts of the world except for Central and Eastern Asia.
- Family: Campanulaceae
- Common names: Cardinal flowers, edging lobelia, puke weed, vomit weed, asthma weed, and Indian tobacco.
- Height: The perennials can grow up to 4 feet in height. The annuals can reach a maximum of 14 inches in height.
- Hardiness: Annuals – USDA zones 1-10, Perennials – USDA zones 2-10
- Uses: Trailing, hanging baskets, edging, window boxes, folk medicine, deck or patio railing.
- Life cycle: Half hardy perennial or annual
- Light: Either under the full sun or in partial shade. The older types of lobelia cannot tolerate the heat at all, which is why it should be planted in partial shade.
- Temperature: The ideal temperature for this plant type is 70 degrees F.
- Soil requirements: It requires moist, humus-rich soils with a pH of 6 to 7.5 and it must be well-drained. Keep in mind; soil requirements vary from species to species.
- Water requirements: It is important to keep the soil evenly and light moist. You must water two times a week for garden plants. For potted plants, daily watering is required.
- Fertilizer: Before planting any species of lobelia, make sure there is a lot of organic matter and compost in the soil. Fertilize the soil two times a month with the help of a water-soluble liquid fertilizer that has high phosphorus levels.
- Grooming: To make sure the blooms are not getting disrupted, deadhead the plant frequently. Tips should be pinched back so the growth is bushier. After the first flowering has taken place, prune the entire lobelia plant by half an inch as it will promote more flowering.
- Flowers: Lobelia produces large amounts of 5 lobed, asymmetrical flowers that are available in blue, violet, purple, white and red shades throughout the summertime.
- Foliage: The lance-shaped, small leaves are hidden under the flowers. The color of the leaves ranges from medium shades of green to really deep ones. There are a few types that have bronze edges leaves.
- Pests: Lobelia is vulnerable to red spider mite infestation which leads to the color of the leaves changing and eventually they all fall. The best thing to do is prevention. Frequently spraying the plant with cold water can ensure that no red spider mites will even come near the plant. Adding a couple of drops of horticultural neem oil pesticide with the water will make the effects even stronger.
- Issues: If the soil of the lobelia plants becomes too dry, the plant will not be able to produce any flowers during the summer months. When a situation like this arises, it is important to perform thorough pruning followed by deeply watering so the issues can be resolved. It is important to make sure the soil stays moist so you can prevent such issues. To make sure the moisture is trapped in the soil, you can add a few inches of organic mulch onto the surface.
- Miscellaneous: Lobelia plants repel deer and rabbits, but butterflies and hummingbirds are attracted towards the beautiful flowers.
Types of Lobelia Flowers
It is safe to say that Lobelia erinus (native to South Africa) is one of the most popular and compact lobelia species. Also known as the trailing lobelia, this tender perennial grows as an annual species and features masses of vibrantly striking colored flowers that are yellow or white in the center. These flowers blossom from the early springtime all the way to the early frost period. The flowers of this lobelia species range from the traditional violet and blue and more unusually colored like reddish-purple, white, and pink. Each flower is a two-lipped tubular flower that is 0.5 inches long. The lower lip of the flower is larger compared to the top one. The flowers are produced in loose clusters and survive the best during the cooler summer weather. However, if the summer months are really hot, it is possible for the color of the flower to fade. The branching stems are quite leafy, but they have linear, narrow green leaves. Sometimes, the green foliage is more on the bronze foliage size.
The Lobelia erinus is a versatile lobelia species and it can be used for many different things. The common uses of this species would include putting them in window boxes, hanging baskets, or containers. By placing them in these things, they can gracefully be over the edge, looking as beautiful as always. The upright variety of the Lobelia erinus is the ideal choice for flower beds and edging. This species is easy to grow and quite colorful.
The Lobelia erinus plant has the ability to grow 6 to 9 inches in height and 6 to 12 inches in width. It does really well in evenly moist, organically rich and well-drained soils. It is important to make sure this plant is in either partial shade or under the full sun. Through the growing season, it is important to do regular fertilization. This perennial does well in hardiness zones 10-11.
Also known as the great lobelia or the great blue lobelia, the Lobelia siphilitica is a North American native upright and popular perennial. This species has the ability to produce spikes of vibrant blue flowers that sit beautifully on top of lance-shaped, lightly toothed foliage. The plant produces long-lasting flowers that blossom during the late summer to mid-fall time. This lobelia species is quite upright which makes it a great addition to a lot of landscape. This pest and disease-free, low maintenance, hardy plant are short-lived even if it is given utmost love and care. The flowers on this plant are self-compatible but they cannot pollinate themselves, which is why bees and other insects need to pollinate it.
The Lobelia siphilitica has the ability to grow 2 to 3 feet in height and 12 to 18 inches wide. These clump-forming lobelia species do well in humus filled and rich soils. It is important for the soil of this lobelia to be moist or wet, especially during the summertime. The reason is that during the summer, dry spells are everywhere. This lobelia looks gorgeous alongside streams and ponds as well as wild gardens.
The best flower option for the late summertime would be the Lobelia cardinalis (Cardinal Flower). This North America native bellflower plant is a popular, clump-forming, upright perennial that features a profusion of spiked flowers that are abundant in scarlet red color. Each flower is a two-lipped blossom which is 2 inches long. These striking red flowers blossom during the midsummer to early fall time. They blossom on alternate leafed, erect stalks that rise above bright green, glossy leaves. This allows this species of lobelia to add a vertical architectural value to any landscape. This species is low care, extremely hardy, and disease and pest free most of the times. Cardinal flowers are short-lived, even if it has the potential to self-seeds and is growing in ideal locations.
The Lobelia cardinalis has received the Award of Garden Merit awarded by the Royal Horticultural Society. The plant has the ability to grow 2 to 4 feet in height and 1 to 2 feet in weight. It does well in medium to well, rich soils under the full sun or in partial shade. It also has the ability to tolerate bad drainage and damp soils.
Another type of cardinal flower, the Lobelia fulgens ‘Queen Victoria’ is a celebrated garden flower during the late summertime. This lobelia species is clump-forming, upright, and quite popular. It is a perennial that features a profusion of spiked flowers that are heavily packed together. These flowers possess a gorgeous fiery scarlet color and they are two-lipped blossoms. The flowers blossom during the midsummer to early fall time. Like a few of the other lobelia species, this one too is borne erect. The stalks are alternatively leafed and have beet red colored leaves. Automatically and effortlessly, this lobelia species instantly elevated the look of any landscape. Unfortunately, the Lobelia fulgens ‘Queen Victoria’ is also a short-lived flowering species even if it is growing in ideal situations.
Like the previously mentioned Lobelia cardinalis species, this one has won the Award of Garden Merit by the Royal Horticultural Society. This lobelia species has the ability to grow 3 to 4 feet in height and 1 to 2 feet in width. It does well in medium to wet rich soils under the full sun or in partial shade. It can tolerate poor drainage and damp soils.
Considered as being one of the most popular and loved flower for the summertime, the Lobelia x speciosa ‘Vedrariensis’ is an upright, vigorous perennial that beautifully boasts dark violet flowers along with dark green leaves. As the mid-summer and early fall time come near, the dark green leaves turn into a shade of purple. Along with being extremely beautiful, this plant is known to be quite architectural as it adds vertical value to a landscape. This species of lobelia is a cross between Lobelia fulgens, Lobelia siphilitica, and Lobelia cardinalis.
The Lobelia x speciosa ‘Vedrariensis’ has the ability to grow 3 to 4 feet in height and 1 to 3 feet in width. This species of lobelia does exceptionally well in average, medium or wet soils under the full sun or in partial shade. However, this plant craves afternoon shade and loves being in moisture. It adds beauty to cottage gardens and garden beds.
If you are purchasing or starting out with seedlings, the best time to get your hands on lobelia would be the springtime. Go to your local garden center or nursery and keep your eyes open for plants with compact shapes, flowers, buds, and healthy leaves.
Another important thing to know about lobelia plants is that they tend to continuously blood through the spring, summer, and fall time. This is why; you do not need to worry about choosing or purchasing a lobelia plant that has bloomed. You can choose a plant that has not bloomed because when the time comes, it will bloom. A lobelia plant will continue to bloom properly as long as you are taking care of it by checking the soil and keeping the other things in check.
The final verdict is that lobelia plants are very easy to take care of. Just by the presence of these plants, there will be an instant elevation of happiness and color in your patio, garden or porch.
Lobelia plants are the ideal choice for individuals that want to add the perfect amount of beauty and color to their homes. The flowers that blossom on it are strikingly gorgeous, but it is important to take care of them. With the right amount of care, your lobelia plant will stay healthy for longer.