How to Grow Lobelia Plants & Care Tips - Garden Design (2022)

How to Grow Lobelia Plants & Care Tips - Garden Design (1)

Laguna® Dark Blue Lobelia erinus
Photo by: Proven Winners

My favorite color is blue, so I go absolutely giddy every spring when annual lobelia plants start showing up at my local nursery. Not only do many varieties have true blue flowers, a rarity in the garden world, many also love cool weather and are in full splendor during spring and fall. They are a must-have for my spring containers, and anywhere else in my garden where I want to add a blast of blue.

They're not just a one-color wonder, nor are they always a tender annual. There are more than 400 species that include upright and mounding lobelias, annuals, half-hardy annuals, perennials, and even shrubs and aquatic plants. And although cobalt blue may be their signature hue, you’ll also find lobelia flowers in scarlet red, lilac, rose, and vibrant tropical colors.

On this page: The Basics | Types | Growing Tips | Care and Maintenance | Pictures | Design Ideas

On this page:

  • BASICS
  • LOBELIA TYPES
  • GROWING LOBELIA
  • LOBELIA CARE AND MAINTENANCE
  • PICTURES
  • DESIGN IDEAS

BASICS

Hardiness:

Grown as an annual in most zones; perennials vary by species

Height:

Annuals reach a maximum height of about 12 inches. Perennials can grow to be 4 feet high.

Exposure:

Full sun to partial shade.

Bloom time:

Varies by species. Most annuals will bloom from spring through fall, with a lull during midsummer.

Garden uses:

Hummingbird havens, garden borders and groundcovers, rain gardens, woodland gardens, spillers in container combinations, pollinator gardens.

How rare are blue flowers?

Very! They make up less than 10% of the plant kingdom. Blue lobelias are among this elite group, which also includes blue sea holly (Eryngium planum), Siberian larkspur (Delphinium grandiflorum), Lily of the Nile (Agapanthus africanus), Texas bluebonnets (Lupinus texensis), blue daisy (Felicia amelloides), and blue hydrangeas. See more of our favorite blue flowers for your garden.

TYPES

Although there are hundreds of lobelia varieties, these are the types most commonly grown in the home garden:

  • Edging lobelias (Lobelia erinus) and their hybrids are tender perennials grown as warm-weather garden annuals. Often grown as container and edging plants, they can have bushy or trailing habits. The tiny five-petaled flowers bloom in shades of blue, purple, rose, and white, with some accented by white eyes.
  • Cardinal flower (Lobelia cardinalis), named for its showy spikes of scarlet-red flowers, is the most popular perennial variety. Some varieties also have ornamental reddish-bronze foliage. A North American wildflower native to wet areas, cardinal flower can be found growing in marshes, stream banks, and low woods.
  • Great blue lobelia (Lobelia siphilitica), also called blue cardinal flower, is another native perennial wildflower that bears long-lasting bright blue flowers.
  • Lobelia ×speciosa are popular garden hybrids (usually of L. cardinalis and L. siphilitica) with flowers in shades of blue, lavender, pink or red and a long summer bloom period.

What about Lobelia inflata, commonly called Indian tobacco plant?

Due to serious toxic effects, L. inflata is not commonly grown as a garden plant. It has, however, been used for medicinal purposes for many years.

GROWING LOBELIA

How to Grow Lobelia Plants & Care Tips - Garden Design (2)

Container combination featuring Laguna® Sky Blue lobelia.
Photo by: Proven Winners.

When to plant:

In spring, after the danger of frost has passed.

Where to plant:

Most prefer moist, hummus-rich, slightly acidic soil. Some perennial varieties, such as cardinal flower, prefer boggy conditions and can even be grown in standing water.

Light requirements:

In midsummer, most will need some shade to keep them blooming, with the exception of those with improved heat tolerance.

Water requirements:

Water regularly to keep the soil evenly moist, especially during hot, dry weather. Container-grown plants may need daily watering to maintain consistent soil moisture.

Growing from seed:

Although annual types are widely available at garden centers in the spring, you can also start your own plants from seed, sown indoors 8 to 10 weeks before the last spring frost date. Don't transplant seedlings outdoors until a few weeks after the last frost date. Perennial lobelias will often self-sow given the right conditions and usually bloom the first year from seed.

Growing in containers:

Plant in a potting mix rich in organic matter. When using them in mixed container combinations, be sure to team them up with other moisture-loving shade-tolerant annuals and perennials, such as violas, impatiens, and sweet alyssum.

LOBELIA CARE AND MAINTENANCE

Fertilizing:

Perennial varieties can usually get by with a yearly application of fertilizer or compost in the spring. For annuals, fertilize more frequently or apply a continuous-release fertilizer for flowering plants to sustain them throughout the growing season.

Pruning and deadheading:

Most annual lobelias are self-cleaning, so you don’t need to deadhead them. If blooming slows during the heat of summer, the best way to revive them is to cut them back by as much as one-half to two-thirds, followed by regular watering. This radical pruning will regenerate new growth, and by the time the cooler weather of fall arrives, your plants should be in full bloom again. You can also pinch back plants at any time if you prefer bushier growth.

(Video) Lobelia Tech Tip

Avoid pruning back or deadheading cardinal flower and other perennials if you want them to reseed naturally.

Propagating:

Perennials tend to be short-lived, but the plants are easy to propagate by dividing them in the spring or fall or by taking stem cuttings after your plants finish flowering. Unless you plan to let your plants self-sow, divide them every two or three years to extend their lifespan.

Winter protection:

If perennials are covered with heavy mulch over the winter, the roots can rot, especially in warmer southern climates. If you typically mulch your perennial beds to prevent frost heaving and root damage, use a light layer of mulch that won’t completely cover the basal leaves.

LOBELIA PICTURES

Swipe to view slides

Photo by: Proven Winners

Laguna® Sky BlueBuy now from Proven Winners
L. erinus

Type:

Annual; perennial in Zones 9-11.

Height:

6 to 12 Inches

Spread:

12 to 24 Inches

Bloom Time:

Spring until frost

This best seller blooms all season and requires little to no maintenance. Bred to be more heat tolerant than other varieties.

Photo by: Proven Winners

Laguna® Cloud WhiteBuy now from Proven Winners
L. erinus

Type:

Usually grown as an annual; perennial in Zones 9-11.

Height:

6 to 12 Inches

Spread:

12 to 24 Inches

Bloom Time:

Spring through late summer

Large, clean white flowers all season on cascading plants make this an eye-catching spiller to use in containers and hanging baskets.

Photo by: Proven Winners

(Video) Planting Lobelia in the garden

Laguna® Dark BlueBuy now from Proven Winners
L. erinus

Type:

Annual; perennial in Zones 9-11.

Height:

6 to 12 Inches

Spread:

12 to 24 Inches

Bloom Time:

Spring until frost

A rare true blue flower with improved heat tolerance. Laguna varieties don't like wet feet, so be sure to let the soil dry out before watering.

Photo by: Proven Winners

Laguna® Ultraviolet™Buy now from Proven Winners
L. erinus

Type:

Annual; perennial in Zones 9-11.

Height:

6 to 12 Inches

Spread:

12 to 24 Inches

Bloom Time:

Spring until frost

Bright violet purple flowers add color to hanging baskets, containers, and garden borders. Bred to handle summer heat.

Photo by: Age Fotostock / Alamy Stock Photo

‘Crystal Palace’
L. erinus

Type:

Perennial in zones 7-11

Height:

4 to 6 inches

Spread:

6 inches

Bloom Time:

Late spring through early autumn

(Video) String Theory Amsonia, Chocolate Joe Pye, Liatris & Great Blue Lobelia! | Serenity Now Garden

This compact plant packs a big punch with its deep cobalt-blue flowers and glossy bronzed foliage. Tidy bloom-covered mounds are great for borders, edging, or groundcover.

Photo by RukiMedia / Shutterstock

Great Blue Lobelia
L. siphilitica

Type:

Perennial in zones 4-9

Height:

2 to 3 feet

Spread:

1 to 1½ feet

Bloom Time:

August through September

This blue cousin of the cardinal flower produces dense spikes of showy flowers that are magnets for hummingbirds and butterflies. It’s also a wetland native that flourishes in moist garden soils.

Photo by: Walters Gardens

Cardinal Flower
L. cardinalis

Type:

Perennial in zones 3-9

Height:

3 to 4 feet

Spread:

1 to 2 feet

Bloom Time:

July to September

Fiery red flowers are a favorite source of nectar for hummingbirds. Cardinal flowers crave water and are perfectly happy growing in a water garden or at the edge of a stream or pond.

Also try: 'Queen Victoria' (dark maroon foliage) and ‘Ruby Slippers’ (ruby flowers).

Photo by: John Richmond / Alamy Stock Photo

Mexican Cardinal Flower
L. laxiflora

(Video) How to grow a tropical garden - 5 seed packets, only 1 year! 🌱🌴

Type:

Perennial in zones 7-11

Height:

2 to 3 feet

Spread:

5 feet or more

Bloom Time:

Spring through fall; nearly year round in mild climates.

This exotic-looking variety has trumpet-shaped salmon-red flowers with bright yellow and orange throats that hang in clusters on thin red stems. A native of Mexico and southern Arizona.

Spreading, bushy growth habit can be invasive.

Photo by Walters Gardens

'Starship Deep Rose'Buy now from Proven Winners
Lobelia ×speciosa

Type:

Perennial in zones 6-10

Height:

20 to 24 inches

Spread:

12 to 24 inches

Bloom Time:

June through September

Rose-pink blooms are set off by dark bronze foliage. This long-blooming hybrid thrives in moist conditions. Use in containers, well-watered garden beds, and aquatic gardens.

Photo by Walters Gardens

‘Starship Scarlet’
Lobelia ×speciosa

Type:

Perennial in zones 6-10

Height:

20 to 24 inches

Spread:

12 to 24 inches

Bloom Time:

June through September

Scarlet red flowers bloom on dense, upright spikes. An excellent choice for borders and beds with moist soil. Hummingbirds love the bright red flowers.

DESIGN IDEAS

  • Cascading varieties make attractive spillers in hanging baskets and window boxes.
  • Upright varieties work perfectly as a centerpiece (or ‘thriller’) in containers or along borders. They also add height to cut arrangements.
  • Add in rock gardens, butterfly gardens, or in a deer-resistant landscaping design.

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FAQs

What plants look good with lobelia? ›

The electric blue of some lobelia varieties will complement pansies, violas, white snapdragons, alyssum or dusty miller. Lobelia can also create beautiful, full, mounding containers when planted on their own.

Where does lobelia grow best? ›

For the most part, lobelia isn't too picky about sunlight and can thrive in partial shade to full sun locations. However, if your summers tend to be very hot, it is best to plant lobelia where it will receive direct sun only in the morning and part-shade to shade in the afternoon.

How do I get more flowers on my lobelia? ›

Water plants whenever necessary to keep the soil or compost moist as this will prolong flowering. Feed with a balanced liquid plant food every 2 weeks during spring and early summer and then switch to a high potash one every two weeks from then on. Deadhead and cut back plants after flowering.

Should I cut back my lobelia? ›

Should I Prune My Lobelia? Yes. Cutting back lobelia plants improves their appearance and health. It also encourages the plant to produce more flowers over a longer period of time.

Do lobelia come back every year? ›

There are many types of Lobelia. Some are annuals and some are perennials and some are annuals only in northern climates. Annuals will usually self-seed and come back the next year, while perennials will re-sprout from the dormant plant in spring.

How often should I water lobelia? ›

Perennial Lobelias need regular watering during the first year. Afterwards, the plants become drought-tolerant and require watering twice a week during dry periods. The top 6 inches (15 cm) must remain moist at all times.

How do you take care of a lobelia plant? ›

Once established, the lobelia plant requires little maintenance. During hot, dry periods, care of lobelia requires that the plant should receive frequent watering, however, especially those in containers. A general-purpose liquid fertilizer can be given once a month or every four to six weeks, if desired.

Why are my lobelia flowers dying? ›

Your lobelia plant may wilt with too much water or too little. Keep in mind that a lobelia plant that is wilting does not necessarily always need water. Sometimes lobelia plants wilt when they have too much water. Always check the soil dryness to determine if you should give the lobelia plant some water.

Can lobelia grow in pots? ›

The profusion of blooms makes growing lobelia in a pot an excellent choice. Deciding to grow lobelia in planters is a great way to ensure the success of this flower. Although these flowering plants are beautiful, they do require some specific growing conditions to truly thrive.

How many lobelia plants are in a hanging basket? ›

Plant spacing
PlantFlower pouchEezee Hanging Basket
Lobelia1012
Pansy and Viola1012
Petunia (trailing)88
Primrose and Polyanthus1010
14 more rows

Do lobelia reseed themselves? ›

Lobelia will reseed themselves if you let them, but they're not invasive due to their demand for rich, loose, consistently moist soil.

Is lobelia self seeding? ›

Lobelia after flowering

And you can leave it as it is, but you should keep in mind that lobelia easily propagates by self-seeding, and with chaos reproduction it will bloom later than spring planted seedlings. It is better to collect the seeds and sow them according to our recommendations.

Is lobelia a sun or shade? ›

PLANTING & LOBELIA CARE

How to plant: Lobelia plant performs best with full sun to partial shade and rich, well-draining soil. Choose a site that receives at least 4-6 hours of direct sun.

Do you dead head lobelia? ›

Some obliging plants do not need deadheading. Typically fuchsias, bedding lobelia and salvias either don't set much seed or neatly deadhead themselves.

How big does lobelia get? ›

Height: Annuals reach a maximum height of about 12 inches. Perennials can grow to be 4 feet high.

How do you prepare lobelia for winter? ›

Spread a 2- to 3-inch-thick layer of mulch over the root zone. Too much moisture can kill lobelia during the winter months, so only water it when the soil feels dry beneath the surface. Stop fertilizing lobelia plants in late summer to give any new growth a chance to harden off before the first frost.

Can you grow lobelia from cuttings? ›

Lobelias can be grown from seed but it is also possible to propagate them from cuttings. However, the cuttings that you use should be new growth, not stems that have produced flowers.

Is lobelia invasive? ›

Extremely hardy, low care, and fairly pest and disease-free, Great Blue Lobelia tends to be short-lived, although it may self-seed in ideal growing conditions (without becoming invasive).

Can you over water lobelia? ›

Underwatering may be an obvious cause, but overwatering may make less sense until you realize that under these conditions, plants suffer significant root death, decreasing the amount of fluid and nutrients they can bring to their tissues.

Can lobelia grow in shade? ›

Lobelia. Add lobelias to shade gardens for rich, true blues. These trailing, colorful shade annuals bloom prolifically in spring and fall, almost covering themselves in flowers. Annual lobelia is a cool-season plant that can tolerate most light conditions, including shade.

How long does lobelia take to grow? ›

12-16 weeks

Why are my lobelia leggy? ›

Pinch back the tips of the young lobelia plants when you purchase them from the nursery. Without this initial pinching, the stems can grow long and make the plant look leggy and unkempt. Use your fingertips or a pair of sharp pruning shears to remove just the outside tip of each stem.

How do you divide lobelia? ›

If you water the pot thoroughly and then tip the plant out you can grasp it in two hands. One bunch of foliage in each hand. Hold it right down at the base of the stems and then pull the clump apart very gently. Do not worry if you feel some roots tearing.

How do you care for lobelia in a hanging basket? ›

Water the hanging lobelia basket often to keep the soil moist but not waterlogged. Apply the water to the top of the basket until it runs freely out the bottom and sides of the container. During the height of summer, the hanging basket may require daily watering to keep the soil moist.

Are there different types of lobelia? ›

Lobelias

How do you repot lobelia? ›

Re-pot if your lobelia is root bound, outgrows its pot or when the water doesn't quickly drain. Trim back the roots and the top of a plant and repot in the same container (or the next larger size) with some fresh potting soil.

Can you grow lobelia indoors? ›

Lobelia seeds can be sown directly indoors. These plants typically require an area with full sun but will tolerate partial shade. They also prefer moist, rich soil. Start indoors about 10 to 12 weeks prior to the last frost in your region.

What flowers go with lobelia? ›

Lobelia pairs well with other summer bloomers such as pansies, geraniums, and daisies. Depending on the variety, lobelia can be tucked into perennial beds as edgers and fillers, or into containers or hanging baskets as spillers.

How far apart should lobelia be planted? ›

Lobelia seeds should germinate within 10 and 21 days. When the seedlings are large enough to handle transplant them into trays 5cm apart.

What does lobelia symbolize? ›

In some cultures, they symbolize love while others associate them with good luck or prosperity. These flowers are also often worn as jewelry to symbolize love or friendship. These flowers are seen as symbols of love and affection.

When can you plant out lobelia? ›

Overview
Official Plant NameLobelia
FlowersShowy, two-lipped flowers
When To SowApril, May
Flowering MonthsJuly, August, September
When To PruneSeptember, October
5 more rows
18 May 2021

How do you use a basket as a planter? ›

Can You Plant in a Wicker Basket? // Garden Answer - YouTube

How do you organize plants in hanging baskets? ›

How to plant a hanging basket - YouTube

How do you keep lobelia blooming all summer? ›

All lobelias need sun or partial shade, and reliably moist soil. Annual lobelias look great in summer containers, particularly the trailing types, which look great spilling over the edge of a hanging basket. Growing in partial shade will ensure that the plants flower for longer, especially in a very hot summer.

How do you start lobelia? ›

How to Sow Lobelia:
  1. Best sown indoors 10-12 weeks before last frost at alternating temperatures of 55 and 72°
  2. Provide NO cover as light aids in germination.
  3. Expect germination in 15-20 days.
  4. It is not recommended to sow the annual Lobelia seeds outdoors.
  5. Seeds are very small.

How long does it take for lobelia to bloom from seed? ›

Sow thinly and just press into seed-starting formula. Keep the soil moist at 65-75 degrees F. Seedlings emerge in about 20 days.

How do you get seeds from lobelia? ›

How To Collect Lobelia Seeds, How To Harvest Lobelia ... - YouTube

What temperature can lobelia tolerate? ›

The keys to growing Lobelia erinus primarily are that they must never be allowed to dry out and that they prefer cool weather, with night temperatures ranging between 50 to 70 degrees.

Is lobelia an evergreen? ›

Plant Profile: Lobelia

These x speciosa hybrids exhibit a vibrant range of colours from white, blue and deep purple through to vibrant red, and tend to send their flowering stems up 40cm to 1.2m above fleshy, evergreen rosettes.

Can you put lobelia in hanging baskets? ›

Lobelia. Lobelia erinus is a popular bedding plant for hanging baskets and summer containers. It comes in a range of colours, including white, purple, pink and brilliant shades of blue. Grow in full sun, don't let the compost dry out, and feed regularly.

Does lobelia bloom in shade? ›

Lobelia. Add lobelias to shade gardens for rich, true blues. These trailing, colorful shade annuals bloom prolifically in spring and fall, almost covering themselves in flowers. Annual lobelia is a cool-season plant that can tolerate most light conditions, including shade.

How do you grow lobelia in hanging baskets? ›

Plant trailing lobelia along the edge of the hanging basket so it cascades over the sides. Plant compact lobelia in the middle of the basket to form a dense mound. Applying a 2-inch layer of sphagnum moss around the the lobelia plants will help keep the soil moist during the hot summer months.

Can you plant lobelia with tomatoes? ›

One of my favorite combinations to plant is a tomato or lettuce plant (which also likes cooler temperatures), petunias, lobelia and alyssum.

How many lobelia plants are in a hanging basket? ›

Plant spacing
PlantFlower pouchEezee Hanging Basket
Lobelia1012
Pansy and Viola1012
Petunia (trailing)88
Primrose and Polyanthus1010
14 more rows

Why do my lobelia keep dying? ›

Your lobelia plant may wilt with too much water or too little. Keep in mind that a lobelia plant that is wilting does not necessarily always need water. Sometimes lobelia plants wilt when they have too much water. Always check the soil dryness to determine if you should give the lobelia plant some water.

Is lobelia good in pots? ›

Growing Lobelia in Containers

The profusion of blooms makes growing lobelia in a pot an excellent choice. Deciding to grow lobelia in planters is a great way to ensure the success of this flower. Although these flowering plants are beautiful, they do require some specific growing conditions to truly thrive.

How do you maintain lobelia? ›

All lobelias need a spot in full sun or part shade, and reliably moist soil. The annual varieties don't need deadheading but can be cut back in mid summer to maintain bushiness and good flowering. Deadhead perennial varieties once they've finished flowering and cut foliage back in autumn.

Is lobelia a spreading plant? ›

Lobelia - The Ultimate Growing Guide from Proven Winners. Annual lobelia (Lobelia erinus) blooms prolifically for months, with a trailing, spreading or bushy habit that's perfect for containers and landscape plantings.

How big does lobelia get? ›

Height: Annuals reach a maximum height of about 12 inches. Perennials can grow to be 4 feet high.

How do you divide a lobelia plant? ›

If you water the pot thoroughly and then tip the plant out you can grasp it in two hands. One bunch of foliage in each hand. Hold it right down at the base of the stems and then pull the clump apart very gently. Do not worry if you feel some roots tearing.

What flowers go with lobelia? ›

Lobelia pairs well with other summer bloomers such as pansies, geraniums, and daisies. Depending on the variety, lobelia can be tucked into perennial beds as edgers and fillers, or into containers or hanging baskets as spillers.

How far apart should lobelia be planted? ›

Lobelia seeds should germinate within 10 and 21 days. When the seedlings are large enough to handle transplant them into trays 5cm apart.

What should you not plant near tomatoes? ›

Plants that should not share space with tomatoes include the Brassicas, such as broccoli and cabbage. Corn is another no-no and tends to attract tomato fruit worm and/or corn ear worm. Kohlrabi thwarts the growth of tomatoes and planting tomatoes and potatoes increases the chance of potato blight disease.

What plants keep bugs away from tomatoes? ›

More Herbs & Flowers to Plant with Tomatoes to Keep Bugs Away: Don't just stop at planting Marigolds with your tomatoes. For further protection from pest bugs, you can also plant basil, beans, bee balm, borage, sweet alyssum, chives, garlic, nasturtium, mint, anise, onion, and parsley.

Videos

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4. Lobelia plants ന്റെ മനോഹരമായ ദൃശ്യങ്ങള്‍ /Lobelia plant full caring /Home garden ideas by farha
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