Eustoma is not known to most hobby gardeners. Behind it is a plant that originally comes from very specific habitats. It became known as a cut flower in Europe and is now being rediscovered as a pot plant.
What is Eustoma and where does the plant come from?
Eustoma, also known as prairie gentian, is an herbaceous plant native to America's deserts and prairies. It is popular as a cut flower and is cultivated as a pot plant. Eustoma has bell-shaped flowers of various colors and blooms from July to August.
Origin
Eustoma describes the genus of prairie gentians with two to three species, but the Latin name is largely unknown. The commonly cultivated large-flowered prairie gentian is more widespread under the name Lisianthus russelianum. This name for the popular cut flower is now considered outdated.
Eustoma grandiflorum originally comes from the desert regions and prairies of America. Their range extends from Mexico through Texas to Colorado and Nebraska. Its triumph within Europe began at the beginning of the 19th century. It belongs to the gentian family. Eustoma is the Greek expression for “beautiful mouth”.
Growth
Eustoma species grow as herbaceous plants that are one to two years old. They reach heights of between 15 and 60 centimeters. The habit is upright and loosely bushy. Prairie gentians grow in clumps and develop taproots that extend deep into the earth, drawing nutrients and water from the deeper layers. The root system reacts extremely sensitively to disturbances.
leaves
Prairie gentians develop dark green to blue-green leaves that appear slightly fleshy. The lanceolate leaves are arranged opposite each other on the stem. They reach a length of between eight and ten centimeters.
Flowers
The plants develop bell-shaped individual flowers that grow on 40 to 60 centimeter long flower stalks. Some species are double-flowered and develop two flowers on one stem. The flowers grow up to two centimeters large. Your color palette is wide. Prairie gentians bloom in pink, purple, blue or white. Some species produce bicolor flowers. Carmine red or yellow specimens occasionally occur. The flowering period of the ornamental plants extends from July to August. Under optimal conditions, the plants bloom until September.
Fruit
After flowering, prairie gentians form capsule fruits, which are scattered fruits. Once mature, they open along preformed structures and disperse seeds as the wind moves the flower stems. They fall to the ground and are washed away with the rain or spread by the wind. The seeds are microscopic and can be seen as dust with the naked eye.
Seed development
The seeds germinate very quickly under high temperatures. If the thermometer rises above 30 degrees Celsius, the seedlings develop into two-year-old plants. In the first year, a basal rosette of leaves grows. The plants only bloom in the second year. The weather also plays a role in this development. If the winter months are rainy and cool, Eustoma species grow as annual plants.
Usage
In the past, Eustoma species were grown to be used as cut flowers. The exotic beauties are now conquering window sills and living rooms as potted plants. Their flowers are extremely decorative. Although the cultivated species are only annual and are therefore kept for one season, two-year cultivation is possible with good care.
The delicate flowers represent charisma, appreciation and gratitude. That's why the plants are often used as cut flowers for bouquets. You can create a bushy still life with different plants. Ilex, Amarine and sea lavender go well with prairie gentian.
Multiple uses:
- in bouquets
- in planters for interior greenery
- in larger pots for the winter garden
Poisonous
Eustoma species are classified as non-poisonous. There are no known signs of poisoning in pets or children. However, you should remind children that not every beautiful-looking flower should be eaten. Too large quantities can irritate the gastrointestinal tract.
Location
As plants of deserts and prairies, Eustoma species prefer full sun locations. Hot temperatures do not cause them any problems. Houseplants can be grown in a shady spot. They also thrive at normal room temperature.
Earth
Prairie gentians require well-drained soil with a pH between 6.5 and 7.0. If the substrate falls below this value, there is a risk of zinc poisoning. The plants can no longer grow well and wither away. The plants like a slightly acidic to neutral environment. A clayey soil with a high proportion of humus is ideal.
Propagate
It makes sense to propagate these plants, otherwise you will only enjoy their beauty for one season. You can purchase prairie gentian seeds from specialist retailers. It is easier to collect the fruit capsules as soon as they have dried out. Propagation from cuttings is also possible.
Cuttings
Prairie gentians can be successfully propagated from cuttings. Cut a shoot into several pieces of at least two centimeters. Each cutting should have a pair of leaves so that the metabolism works. Place them in a nutrient-poor growing substrate and place the pot in a bright and warm location. The soil temperature should not fall below 20 degrees Celsius. Keep the substrate moist regularly to encourage root formation.
Sowing
Between October and March you can sow the seeds you collected yourself and grow new plants. Fill a planter with nutrient-poor potting soil. An excess of nutrients causes the shoots to shoot up and become unstable. In lean substrate, the taproot can develop well and form numerous fine roots that draw nutrients extensively from the substrate. The pH value is ideally between 6 and 6.5.
The seeds germinate in light and should only be lightly covered with soil. You can also leave the seeds exposed. Direct sunlight does not harm the seeds. The desert plants have adapted their seeds to the hot conditions so that they do not dry out so quickly.
After a few weeks, the seeds begin to germinate. This development occurs faster the warmer the temperature. Make sure the soil temperature is between 20 and 25 degrees Celsius. Keep the substrate constantly moist. High humidity is not absolutely necessary, as conditions in the original habitats are predominantly dry during the growing season. By placing foil or an inverted glass over the growing container, you can ensure that the substrate dries out more slowly.
In the pot
Prairie gentians are only cultivated as pot plants in Europe. Since the plants, which grow primarily as annuals, require warm temperatures, they quickly die outdoors. Use a pot with a drainage hole and cover the bottom with a layer of expanded clay or clay shards to ensure optimal water drainage. The pot should be sufficiently deep so that the taproots can develop optimally.
Balcony
The desert beauty likes to spend the summer on the balcony. Move the pot outside when frost no longer occurs at night. If you have previously cultivated the plant on the windowsill, it should be carefully acclimated to sunlight that is not filtered through window glass. A rain-protected location with morning and evening sun is ideal for acclimatization. The plant needs at least four hours of sunshine per day.
In the greenhouse
Eustoma varieties are grown in greenhouses because warm temperatures can be guaranteed here. This cultivation causes the plants to develop long flower stalks. Such specimens have a particularly beautiful appearance. When grown in full sun conditions, prairie gentians grow compactly and produce short flower stalks.
Giessen
Watering Eustoma species requires sensitivity because this is where most mistakes happen. The substrate should be kept evenly moist. Irregular watering and strong fluctuations in the moisture balance of the soil cause problems for the plant. It does not tolerate waterlogging. If water collects in the coaster, you should throw it away immediately. If left for more than two days, the roots may rot. A dry substrate also causes stress for the plant. It becomes stunted as soon as the roots dry out completely.
Fertilize
Depending on the abundance of flowers, prairie gentians require more or less nutrients. You can give the plants a liquid fertilizer via irrigation water once or twice a week. A dosage of half the concentration is optimal to cover the nutrient requirements. Fertilization takes place between April and September. This measure is not necessary if you have planted the plant in fresh substrate after purchase.
Cutting
You can regularly remove spent flower stems throughout the growing phase so that the plant can fully invest its energy in developing new flowers. Cut off yellowed parts of the plant to preserve the beauty of your prairie gentian. You don't need scissors for this care measure. The withered flowers and leaves can be clipped off with your fingernail.
Transplanting
It is not necessary to repot the prairie gentian. As seasonal plants, most of the varieties offered only grow for one year. If you get your plant through the winter with good care, you can give it fresh soil by transplanting.
hardy
Eustoma species are not hardy. Overwintering in a bright and frost-free place is possible. Temperatures in the winter quarters should be between ten and 15 degrees Celsius. Continue to water regularly. Watering amounts are more economical during the wintering phase. When the plant is in a dormant state, it does not need additional fertilization.
Pests
Prairie gentians are occasionally attacked by thrips. They settle on leaf surfaces and flowers with predominantly light colors and suck the plant sap from the veins. You can recognize an infestation by finely speckled spots on the parts of the plant that have a silvery shimmer. If you look closely, you can see tiny dots of feces. If the plant is severely infected, the leaves and flowers curl up and tend to turn brown.
The pests prefer to spread in dry conditions. Increasing the humidity or spraying the affected areas destroys the pests and also damages the plant. It is better to use predatory mites to combat thrisps on your prairie gentian.
Fungal infestation
Moist and cool conditions provide an ideal environment for fungal spores to spread en masse on plants.
Phytophtora
Waterlogging causes the roots to rot. Fungi of the genus Phytophtora spread along the roots, causing significant damage. The plants let their leaves and flowers hang limply until they eventually die. If your plant is affected, you should dispose of it completely with household waste. Treatment is difficult and makes little sense for plants cultivated as annuals.
Gray horse
The fungal pores of the genus Botrytis often attack the stem base of weakened plants grown in greenhouses. High humidity and a lack of air circulation allow the spores to spread ideally. They damage the plant tissue, so that vitality is negatively affected. You can prevent an infestation with the right care.
How to prevent fungal infestation:
- Make sure there is good ventilation
- Water the plant sparingly but regularly
- Improve substrate permeability with loose material
- drain excess water from the coaster
- avoid cultivation in a damp greenhouse
Brown spots
Occasionally brown spots form on the leaves. They can be a sign of sunburn. If the plants are suddenly moved from the windowsill into the blazing sun on the balcony or terrace, the leaves cannot get used to the direct sunlight. In the room, the light was filtered through the window pane so that the radiation could not cause any damage.
Brown spots can no longer be removed. Place the plant in a sunny spot for a while and remove the stained leaves.
Not blooming
Eustoma species react extremely sensitively when their root ball dries out. Under these circumstances they drop existing flowers and fresh buds. In their original distribution areas, the growing seasons are spread over spring and autumn. They are interrupted by summer dryness and winter cold. The loss of flowers and buds in dry conditions is a natural adaptation.
If the flower buds of your eustoma do not open shortly after purchase, the wrong location may be the cause. If the plant is too dark, it will not produce any flowers. Place the pot in a bright place with direct sunlight. The plant will recover quickly and open its flowers.
Tip
If you have successfully grown a prairie gentian from seeds or cuttings, you can enjoy the beauty of the plant for another year. In the early growth phase, cut off the shoot tip so that branches form just below the cut. Let them grow and after a short time separate the tips again. In this way the prairie gentian grows bushy.
Varieties
- Adom: Flowers violet-red or white and reddish.
- Advantage: Early flowering variety with thick flower stalks. Suitable for particularly high temperatures. Double flowers in yellow, green-white, pink, purple or cherry.
- Mazurka: Uniform growth with dense branches. Blooms white or blue, slightly fringed petals, medium-sized flowers.
- Little Summer: Multi-flowered varieties in white, creamy white or orange. Flowers small and semi-double with solid petals.
- Papillon: Small-flowered varieties, slow growing. Suitable for cultivation in very warm locations. Blooming in a light pink.
