How to Plant, Grow, and Care for Lisianthus
Are you someone who’s ready for a gardening challenge? Are you desperate for a cut flower that will thrive in hot, dry conditions? There may be an answer to your solution in a little-known flower called lisianthus. In this article, gardening expert and cut flower farmer Taylor Sievers shares how to grow this colorful, rose-like flower in your garden.
Roses are red; violets are blue. Lisianthus is red, blue, purple, pink, orange, yellow, and even lime green shades, too! What other flower looks like a rose but can naturally be lime green? Lisianthus, sometimes called prairie gentian or Texas bluebell, is an ornamental member of the Gentianaceae family. This family is known for their smooth leaves, bitter taste, elegant flowers, and difficulty starting from seed.
Significant breeding efforts for this U.S. native wildflower in recent years have taken the world of floristry and cut flower farming by storm. Today, we have lisianthus in every color of the rainbow. The flowers are prolific (with multiple flowers per stem), thrive in the heat of the summer, and will last 2 to 3 weeks in a vase as a cut flower.
If you have a cut flower garden or often experience drought-like conditions in your garden, then lisianthus is one plant you don’t want to miss out on! Read on to learn more about this enigmatic flower!
|common name Lisianthus|
|botanical name Eustoma grandiflorum syn. russellanium|
|plant type Biennial, Hardy Annual|
|bloom colors Blue, purple, white, pink, green, yellow, mixed|
|sun requirements Full Sun|
|water needs Low|
|height 24 to 30 inches|
|spacing 4 to 9 inches|
|hardiness zones USDA Zones 8 to 10|
|soil needs Sandy loam|
|pet toxic No|
History and Cultivation
Lisianthus is native along the 100th meridian to short grass prairies from western Nebraska and south to Texas and northern Mexico. It prefers dry winters and sandy soils, mainly growing as a biennial in the wild. The wild blooms are typically a shade of purple.
Lisianthus was fairly unknown in the floriculture world of the United States until about the 1980s. Gerald Klingaman, a retired horticulturist, writes that he didn’t know about this flower until the Japanese released some highly ornamental specimens to the trade.
When it first appeared in seed catalogs, it was called Lisianthus russellianus. When it was later recognized as part of the Eustoma genus, people were used to calling it Lisianthus, so the name stuck around. You may hear lisianthus called Texas bluebell, bluebell gentian, or prairie gentian.
Today, lisianthus comes in not only the familiar colors of blue and purple but also shades of pink, apricot, champagne, white, green, yellow, and beautiful bicolors called “picotee,” where the outer edges of the petals are darker than the centers. Some varieties have single petals, while others have a double layer of petals. A few cultivars have small flowers arranged in clusters.
Most lisianthus plants are grown as annuals, but in USDA hardiness zones 8-10, they’re often biennial plants. This means they won’t flower until the second year, and then they’ll die. In USDA zone 10, you can grow it as a perennial that returns yearly.
Reasons to Plant Lisianthus
Have you been eager to grow beautiful roses, but the cost and maintenance of rose plants are prohibitive? Enter the flower that is sometimes mistaken for a rose: the lisianthus. Here are a few reasons why you should consider growing this gorgeous plant:
Lisianthus flowers are often planted in gardens to add a fresh and elegant feeling. They come in a large range of colors that attract a diversity of pollinators to your garden and look gorgeous while doing it.
Affordable and Low-Maintenance
Compared to a rose bush, lisianthus is affordable and low-maintenance. They don’t require nearly as much water, pruning, fertility, or pest management as a rose bush. They don’t have many insect or disease issues and can be quite drought-tolerant once established. Moreover, the seeds are very affordable.
Lisianthus plants are a great addition to your garden if you need help attracting pollinators. Bees, butterflies, and hummingbirds will likely flock to these blooms all summer long. Cutting them will encourage new growth so that you can keep the gorgeous flowers both inside and outside throughout their growing season.
One drawback to this plant is its difficulty to grow from seed, but you can purchase a seed packet for pennies compared to one rose bush. While they are primarily grown from seed, they can also be propagated by cuttings.
Lisianthus seeds are extremely small. Because they are so small, many seed companies sell pelleted seeds. Pelletting is a process where inert materials are used to coat a seed to make it a more uniform size and shape or a larger, easier-to-handle size.
Seeds should be started indoors approximately 10 to 14 weeks before the last expected frost. In many climates, January is ideal. The seeds are extremely slow to start and grow, so give them plenty of time.
Sow seeds on the surface of your moist germination mix and keep the seeds around 70° to 75°F until you see germination. You can keep seeds at this temperature by using a heat mat or placing them in a warm area, like on top of your refrigerator. Use a humidity dome or plastic wrap to cover your seedling tray or pot to retain moisture.
You may need a magnifying glass to see the tiny seedlings initially. Once they have germinated, it is very important to remove any bottom heat. Lisianthus are prone to a phenomenon called rosetting. Essentially, this means they will stay dormant if temperatures are too high. Keep the seedlings between 50° and 65°F to prevent rosetting.
Pro Tip: The key is to keep lisianthus cool while they’re small. Mimic nature! In the wild, lisianthus germinates in the cool, moist early spring.
Because they are so difficult to start from seed (they’re slow and prone to root rot), many commercial growers purchase them as plugs. Plugs are seedlings ready to be transplanted once you receive them from the grower.
Unfortunately, plugs can be cost-prohibitive for the home gardener due to the minimum order quantity and cost of shipping. If you live in the southern United States, you may be able to find a local nursery that sells the plants as starts.
Pro Tip: It is not recommended to sow lisianthus seeds directly into the garden. Starting indoors is the preferred method.
In zones 8 and warmer, these heat-loving plants are self-seeding. You can allow nature to take its course at filling your flower beds. The plants don’t like to have their roots disturbed, but if you want to move a plant from one location to another, you can gently dig up seedlings and plant them where you want them.
You can save lisianthus seeds after the blooms have died and sprinkle them over the soil. The seed needs sunlight to germinate, so press them gently into the soil but don’t allow them to get covered up. Avoid planting them in unprotected open areas since the wind may blow away the superfine seed. Even greenhouse growers may have a lot of luck with lisianthus in this regard.
You can propagate lisianthus by stem cuttings in the spring. This works great if you have a plant you want to multiply or you know a fellow gardener willing to share some stems.
To propagate by cuttings, snip off a stem section with at least 4 to 6 sets of leaves. Pull off the lowest set of leaves and dip the end in a rooting hormone, covering the spot where the leaves just were that you pulled off. This is where the new roots will arise.
Place the cutting in a moist, loose mix of peat moss or coconut coir mixed with perlite. Poke a hole so the cutting can be placed without rubbing all the rooting hormone off. Firm the mix around your cutting so it is held in place.
You need to keep your cutting moist but not waterlogged at this time. Place a humidity dome or the top of a plastic soda bottle or milk jug over the cutting to keep the humidity high around the cutting. Mist periodically over the next 4 weeks.
In about 4 to 6 weeks, you should start to see roots and maybe some new growth. Once the cutting has rooted sufficiently, you can transplant it into the garden or a larger pot.
Lisianthus seedlings are ready to be transplanted when they have four sets of true leaves. True leaves are leaves that emerge after the initial first set of leaves. The first set of leaves are called cotyledons.
Cotyledons are seedling leaves that were already developed inside the seed. They will typically be shed when the first true leaves emerge to start doing the work of photosynthesis (basically, the plant’s process of creating its energy).
Germination to transplant can typically take about 60 to 90 days. (It’s the long game with these guys, remember?)
Lisianthus can withstand some cool spring temperatures. If you plant in a protected space like an unheated greenhouse or cold frame, you can transplant about a month before your expected last frost.
If you are planting outside, you can transplant them outdoors starting 2 weeks before your expected last frost. Be sure they are hardened off to their new environment before transplanting.
Lisianthus are very upright in growth habit and can be prone to flopping over if not supported by staking or flower netting. Gardeners get around this by planting lisianthus with tight spacing, sometimes as close as 4 inches apart! You can plant lisianthus anywhere from 4 to 9 inches apart.
There are dwarf varieties that will not flop, like the tall varieties that can reach up to 3 feet. These will reach heights of only 6-10 inches tall.
How to Grow
Lisianthus has a bit of a reputation for being difficult to grow. It may seem that way to beginners, but once you know how to care for them, putting it into practice is easy.
Be patient when growing from seeds since they take a very long time to show signs of life. They can take up to 3 weeks to germinate, and it may be 6 months before you see the first flower.
Lisianthus requires a lot of sun for proper growth and flowering. At least 6 to 8 hours of direct sunlight per day is ideal. In warmer climates, pick a site that will receive full sun in the morning with partial shade in the afternoon when the sun is the most brutal.
In climates with mild summers, such as the Pacific Northwest, you may not need as much shade in the afternoon, and they can usually tolerate full sun or bright light conditions.
If you start seeds indoors, a grow light will be necessary to produce healthy seedling growth since a window provides limited sun, and they’ll need something that mimics the brightness of the full sun for at least part of the day.
Remember that lisianthus is native to the open plains in the southern U.S. and northern Mexico, so mimicking that environment in the garden will allow this beautiful flower to thrive.
Lisianthus are drought-tolerant plants because they have low water requirements. If you miss a watering or two, your flowers should be OK. However, they are extremely intolerant of being waterlogged. Rock gardens and xeriscape plantings are perfect for this plant.
Just remember, as seedlings and establishing transplants, lisianthus prefer cool, moist conditions like early spring. Once established, they will be much more tolerant to dry conditions.
Water lisianthus at the base and ensure the water doesn’t touch the leaves. Soaker hoses will be the easiest way to accomplish this in raised beds and on the ground.
Be careful not to overwater since that can increase the chances of your flowers contracting plant diseases. Watering early in the morning is ideal so the water can soak into the ground before the sun evaporates any excess moisture. It will also give the soil time to dry out before nighttime, reducing the risk of diseases.
Remember, in their native habitat, lisianthus enjoys a hot summer with dry spells that involve just a few drops of rain. If growing in damp climates, they’ll need less watering and may even suffer from too much water. As hot summers fade during the late summer months, you can gradually decrease the watering needs.
Because lisianthus is intolerant of waterlogged conditions, well-draining soil is essential. You must prevent water from pooling up around the roots. Lisianthus prefers well-draining loam soils or sandy to sandy loam soils to thrive.
Lisianthus prefers a pH of 6.5 to 7.0. It won’t grow well in acidic soil because more acidic soils can lead to zinc toxicity, which slows plant growth. They are also salt-sensitive.
If your planting site has more clay, increase drainage by amending the soil with organic matter, like well-rotted manure or compost.
Another great option is to plant lisianthus in a raised bed. Raised beds naturally have better drainage, and you can control the type of soil in the raised bed because you can fill it yourself. Birdies Raised Metal Garden Beds are the perfect sustainable, rot-resistant, DIY solution for including raised beds in your garden.
Climate and Temperature
These elegant heat-loving plants are winter hardy in USDA zones 8 to 10. Some gardeners contend that they can be hardy in zone 7. I have successfully overwintered lisianthus inside an unheated greenhouse in zone 6a. The point? Lisianthus can withstand some freezing temperatures.
The ideal soil temperature is 59-73°F (15-23°C). The lowest air temperature a mature plant can survive outdoors is 10°F (-12°C).
If you live in zones colder than 8, you must bring your plants inside until the temperatures warm up again. Growing in a pot is ideal in cold climates.
Provide Cool Weather While They Establish
In the wild, the lisianthus growth habit is more like a biennial. During the first year of growth, the plant will form a mound of leaves and send forth long shoots with flowers in the second year.
Most ornamental varieties are grown like an annual, but it takes a long time to reach maturity and bloom. Again, they can withstand freezing temperatures with some protection in cooler climates.
When grown as an annual, temperature is key to preventing rosetting. Rosetting will cause a delay in growth and flowering. Allan Armitage and Judy Lauschman, authors of the guide Specialty Cut Flowers, stress the importance of avoiding temperatures above 70°F “like the plague,” especially at night.
Seeds can be started with heat mats, but once germinated, they must be grown in cool temperatures (45° to 65°F) for most of the seedling stage to prevent rosetting.
Slow-release fertilizers are recommended at transplant time. Nitrogen will boost the plant, but look for a fertilizer with just as much potassium (K) as nitrogen (N).
Applying a fertilizer high in potassium throughout the growing season will increase the number of gorgeous flowers you have on each lisianthus plant. Using a fertilizer high in nitrogen will make the plants favor foliage instead of flowers.
Fertilizers that are higher in potassium are potash, kelp meal, and alfalfa. Alfalfa meal or pellets are also a good source of nitrogen. Fish emulsion has both nitrogen and potassium but is typically higher in nitrogen.
Another nutrient that is key for lisianthus development is calcium (Ca). Calcium deficiency will show up as a tip burn on the leaves. Many calcium fertilizers are applied as a spray on the leaves (called a foliar application). However, plants uptake their calcium better via the soil, and most soil already has ample calcium to support your plant’s needs.
Some gardeners like to pinch lisianthus when the plant reaches about 6 inches in height. Pinch just above a set of leaves to induce branching.
However, Cornell University reports that pinching will delay flowering and has not been shown to increase the total flower blooms of the plant. Instead, focus on deadheading over pinching.
Deadheading and harvesting the flowers will keep the plant looking tidy and prevent seed set. Once the rose-like flowers bloom, cut them at the bottom of the stem and put them in a vase.
If you allow the flowers to stay on the plant, remove spent flowers to encourage new growth. Look below the spent flower for a point where a pair of leaves is located, and cut off just above that to encourage further growth.
These plants benefit from some support as the stems can get very tall and flop over with winds. Flower netting or corralling with twine and stakes is beneficial if growing in a cut flower garden setting.
Lisianthus varieties are separated into 4 different groups based on their bloom time in response to heat and light.
- Group 1 blooms during moderate light and heat.
- Group 2 blooms in the summer when there’s high light and heat.
- Group 3 blooms later in the summer, when light and heat are moderate.
- Group 4 is less common and is grown mostly for winter production in areas of warm climates.
Group 1 includes the ‘Echo’ series, which will bloom in late June when sown in late January. The ‘Doublini’ series has miniature blooms that resemble spray roses. Both series come in a range of colors. ‘Roseanne Black Pearl’ is a lovely eggplant color of faded purple that’s simply stunning to see in person.
Group 2 and 3 varieties bloom about a month later than Group 1. Popular varieties include ‘Arena,’ ‘Voyage,’ ‘Mariachi,’ and ‘ABC’ series. ‘Voyage’ varieties have lots of ruffling and waving to the blooms, while ‘ABC’ has more layers of petals than many other varieties. ‘Arena’ is very dependable and comes in a wide range of groups and colors.
My favorite varieties to grow as cut flowers are:
Arena Blue Picotee
|bloom colors White with Dark Blue Rim|
|sun requirements Full sun|
|height 21-30 inches|
The Arena series comes in many shades of colors and has cultivars from Group 2 to Group 4. I typically plant the Arenas from Group 3. They are characterized by fully-double flowers that grow atop tall, sturdy stems. One of the most unique varieties is the Blue Picotee, which has white petals that are edged in dark blue.
Corelli™ III Light Pink
|bloom colors Light Pink|
|sun requirements Full sun|
|height 28-38 inches|
The Corelli™ series is simply stunning and known for its large, double flowers with fringed or wavy petal edges. They also span a few growing groups. My top variety is ‘Corelli III Light Pink’. It grows in such a soft and lovely shade of pink.
|bloom colors Dark Blue-Purple|
|sun requirements Full sun|
|height 6-10 inches|
If you’re looking for a dwarf variety for your landscaping or pots, try out the Sapphire series. They only reach about 6 to 10 inches and come in various colors. These are excellent for borders, edges, or even planting in containers. You can also grow it as a houseplant near a window that gets lots of sunshine.
When it comes to pests and diseases, lisianthus doesn’t cause much of a fuss. Most issues are commonly caused by accidental overwatering or allowing the leaves to get wet.
Fungus gnat larvae will damage lisianthus seedlings by feeding on their roots. You may notice fungus gnats inside flying around your seedling trays or pots. Use sticky traps to catch the adults (basically sticky cards that can be hung around the area). The adults will not hurt much, but they lay eggs, and the larvae can become an unseen problem.
Ensure you have good air circulation wherever you start seeds, but don’t let your seedlings dry out. Water as needed.
A product called Mosquito Bits is an organic larvicide that can help kill any fungus gnat larvae in your seed starting trays or near your seed starting area. Made from Bacillus thuringiensis var. israelensis, a naturally-occurring soil bacteria, this treatment is very effective against the larvae but does not typically kill off adults.
Thrips are 1/16th inch long, brown or white, cigar-shaped insects that like to feed on the blooms, especially the lighter-colored blooms. They cause unsightly streaking on dark petals and can transmit viruses as they feed on the plant.
Thrips can become a big problem quickly. When growing outside, your plants might not be affected by thrips as much. Periodically soaking the plant with a hose will help, but when growing in a structure (like a greenhouse), it may be beneficial to release beneficial predator insects that will feed on the thrips.
Lacewings and ladybugs will feed on thrips and can be ordered from different companies as a subscription service, so you can periodically release them to manage infestations. Ensure that the conditions in the greenhouse are conducive to the continued health of your beneficial insects!
Aphids and Whiteflies
While this plant is not particularly attractive to many other pests, other hungry insects may still look to lisianthus for plant sap to eat. Aphids, whiteflies, and thrips may not kill the entire plant, but they will cause damage that will take away from the beauty of the blooms and foliage. Sometimes these bugs are more attracted to plants that are fed an excess of nitrogen fertilizer.
Like fungus gnats, these insects are best controlled through biological control and companion planting. You can knock off some aphids with a heavy spray of water. But repeated applications of neem oil or insecticidal soap are usually best for heavier infestations.
Lisianthus are fairly disease-free once mature. Still, they can be susceptible to certain fungal diseases on the leaves and flowers.
Most gardeners have difficulty with lisianthus when they are starting from seed. Too much moisture will cause the seedlings to rot from damping off or pathogens that attack the roots. Not enough moisture will cause the tiny root system to dry out and wither away. It is a constant balancing act, which is why many farmers and gardeners order plugs instead of bothering with starting from seed.
Some diseases that can affect lisianthus are:
Fusarium is a pathogen that exists in almost all soils and causes root rot. There are fungicide root dips or drenches that can help prevent fusarium infection once transplanted.
If you notice any plants turning brown and dying, remove them immediately to ensure any infections do not spread to the neighboring plants. Discard the infected plant in the trash, not the compost bin.
Cut flower farmers commonly grow lisianthus inside unheated greenhouses to prevent bloom damage and infections. If growing in the landscape or garden, try choosing colored varieties as the white-flowered varieties seem more damaged by rainfall and moisture. Also, single-petaled varieties are less prone to holding water in the flower than doubles.
The best things you can do to prevent disease is plant healthy plants, discard diseased plants immediately, and plant far enough apart to provide good air circulation throughout the garden.
Lisianthus is primarily grown as a cut flower. They are extremely long-lasting in a vase. Their vase life can be up to 2 to 3 weeks.
To harvest the flowers for arrangements, cut just above a set of leaves when at least one flower is fully colored. The flower does not have to be fully open to harvest, although, in my experience, the flowers look better when you harvest them with one fully open.
It can also be grown in landscaping or a patio pot. Because this plant is drought-tolerant, they are great for xeriscapes or rock gardens in some climates. Xeriscapes are plantings of drought-tolerant plants or plants that naturally occur in areas of desert.
While these flowers are very finicky to start from seed, once established, they are extremely low maintenance and beautiful, which makes the challenge worthwhile.
Frequently Asked Questions
Does lisianthus come back every year?
Lisianthus are naturally a biennial or short-lived perennial. In USDA zones 8 and 9, the lisianthus grows as a biennial, so it will last for two years. In zone 10, it’s grown as a perennial that will come back each year. In colder areas, you can grow lisianthus as an annual.
If you want to overwinter them in northern climates, you will need protection like a cold frame, heavy frost cloth, or a greenhouse. The jury is still out on whether flowers produced during the second year are worth the effort of winter protection rather than starting new seeds in late January for the next season’s blooms.
What are the best lisianthus varieties for cutting?
The lisianthus varieties we see today were all primarily developed for cutting. Because lisianthus is so long and lanky, it can be a difficult landscape plant. I prefer the ‘Arena 3’ series and the ‘Corelli 3’ series. They are both dependable and have either layered petals or wavy petals. Avoid dwarf varieties, like ‘Sapphire,’ as they will only grow about 6 to 8 inches tall and won’t be suitable for cutting.
Do lisianthus like sun or shade?
Lisianthus are native to the open prairies, so they prefer full sun (6 to 8 hours of direct sunlight per day). In some cases, you may plant them in partial shade if the shade is mostly in the afternoon. Too much shade will reduce the number of blooms per plant over the season.
Can I overwinter lisianthus?
If you live in USDA zones 8 to 10, you can overwinter lisianthus. Most growers plant their lisianthus in the fall in those warmer regions. You can overwinter lisianthus in cooler climates, but you must have some degree of winter protection.
An unheated greenhouse, cold frame, heavy frost cloth, heated greenhouse, or a variation will need to be utilized to achieve success with overwintering. You may also try mulching the lisianthus with about 10 to 12 inches of straw. Success will vary and may not be worth it.
The prettiest flowers can often be the most finicky to grow. Lisianthus is one of those flowers. Yet, if you’re brave enough to nurture the seedlings for 60 to 90 days, you’re ready to grow this beautiful rose-like flower.
The benefits far outweigh the challenges that come with growing this plant! An array of colors, long-lasting vase life, drought tolerance, and a steady supply of blooms will make all the rigors of the seedling stage worth it.