How to grow potted star flower? Cultivation methods and key points of pest and disease control
Recently some flower enthusiasts have consulted the Huinong website's back office: how do you grow star flower (Pentas lanceolata)? Today we will briefly introduce how to cultivate and manage the beautiful potted star flower. Interested friends can also take a look.
1 Characteristics and traits
1.1 Morphological characteristics
Star flower is an upright subshrub, plant height 25-30cm, leaves dark green, leaf base gradually narrowed with a short petiole. Cymes are borne at the tips of branches, and each inflorescence is composed of about 20 small flowers.
1.2 Growth habits
Star flower prefers a warm, humid environment with sufficient light, and is heat-tolerant and drought-tolerant. It dislikes direct blazing sun and is slightly tolerant of semi-shade.
2 Propagation
Star flower is mainly propagated by sowing, and can also be propagated by cuttings.
2.1 Sowing
2.1.1 Substrate sowing
The substrate can be peat soil, or a special sowing substrate; mix in 50% carbendazim wettable powder at 0.10% of the substrate weight respectively for sterilization. During the process of mixing in carbendazim, water while mixing, so that the substrate moisture content reaches the point where it does not drip when squeezed by hand; after leaving it to air for 24h, it is ready for use.
2.1.2 Seedling containers
Use plug trays for seedling raising, using 105-cell plug trays. When using sowing boxes for seedling raising, the specification is best at 80cm x 50cm x 10cm; if the box is too large, it is inconvenient to carry, and if too small, the utilization rate is low.
2.1.3 Sowing time
Determine the sowing period according to the flowering time and pot specification. A 10cm pot needs 18-20 weeks of cultivation before it can be marketed; a 15cm pot needs 20-22 weeks.
2.1.4 Sowing method
(1) Plug tray seedling raising. Fill the sterilized substrate into the seedling plug tray, then scrape it level, and press a shallow hole in the center of each cell. Because the seed germination rate is low (about 60%), sow 2 seeds per cell. Note that the seeds are light-loving, so do not cover with soil; finally water thoroughly with a sprayer to ensure full contact between the seeds and the substrate.
(2) Sowing box seedling raising. The sowing density is 2,000-4,000 seeds/sq m. According to the area of the sowing box, divide the seeds evenly into several portions, with 1 portion per box. When sowing, fill the bottom of the sowing box with 4cm of perlite and water thoroughly, which can retain water and allow air passage; then add sterilized substrate up to near the top of the sowing box, scrape the substrate level, press moderately, then evenly mix the seeds with 3-10 portions of fine sand and evenly broadcast them on the substrate surface, without covering with soil. Note not to sow along the four sides of the sowing box, because after watering the substrate in the box will shrink during the seedling raising process, and cracks will appear around the edges, which is not conducive to seed germination and seedling growth; finally water thoroughly with a sprayer to ensure full contact between the seeds and the substrate. Because the seeds are tiny and germination is light-loving, do not cover the seeds after sowing. Therefore, a relatively high seedbed and air humidity should be maintained to ensure smooth germination. The suitable germination temperature is 23-25 degrees C. Germination occurs about 2-3 weeks after sowing. After germination, a light substrate passed through a fine sieve can be lightly covered. The sowing substrate requires a pH of 6.50-6.80 and an EC of 0.75.
(3) Post-sowing management. Place the sown plug trays or sowing boxes in an environment of about 28 degrees C during the day and about 20 degrees C at night, and spray water every day to keep the substrate fully moist, with relative air humidity above 80%. Apply nitrogen fertilizer once a week at a concentration of 50 x 10-6 (equivalent to a 0.10% urea water solution), and apply 45% compound fertilizer 1-2 times in between at a concentration of 0.05%-0.08%. During the seedling stage, the substrate EC should preferably be controlled at 1-1.50. Suitable light: 1,000lux during the germination period, 10,000-30,000lux after germination, and 50,000lux for large seedlings.
(4) Seedling stage management. Star flower begins to emerge about 15d after sowing. When 80% of the seeds have germinated and emerged, the ambient temperature should be lowered or the plants moved to a cooler greenhouse for cultivation, maintaining a maximum daytime temperature of 26 degrees C and a minimum nighttime temperature of 15 degrees C, gradually increasing light, strengthening ventilation. The substrate still needs to remain moist, but avoid excessive wetness to prevent leggy seedlings; when the temperature is above 26 degrees C and there is strong sunlight on clear days, a shade net should be used. After 2 pairs of true leaves grow, a 0.10% Peters 20-10-20 solution can be sprayed along with watering, sprayed once every 7-10d. After the first fertilization, a protective fungicide should also be applied once to prevent damping-off. When true leaves grow and the seedlings begin to grow rapidly, keep the substrate moisture at 50%-70%, and let the substrate dry slightly before watering. Try to water in the morning and let it dry by evening. Through the above careful management, strong seedlings with a flourishing, thick root system and no pests or diseases can be cultivated.
2.2 Cuttings can use plug tray cuttings or sowing box cuttings.
2.2.1 Substrate
The substrate only needs to remain breathable. Peat and perlite can be mixed evenly at a ratio of 3:1, and 50% carbendazim wettable powder is mixed in at 0.10% of the substrate weight respectively for sterilization. During the process of mixing in carbendazim, water while mixing, so that the substrate moisture content reaches the point where it does not drip when squeezed by hand. After leaving it to air for 24h, it is ready for use; then fill it into plug trays, press lightly and level, and scrape off excess substrate; or add substrate up to near the top of the sowing box, scrape the substrate level, and press moderately.
2.2.2 Preparation of cuttings
Select robust mother plants and cut current-year tender branches from the mother plants; such cuttings have the highest endogenous auxin content and the strongest cell division ability. Cut the collected tender branches into small sections of about 7cm, remove the lower leaves, and cut off part of the upper leaves. After cutting, soak them in clean water and keep them moist for later use.
2.2.3 Inserting into the substrate
Insert the cuttings into plug trays or sowing boxes. For plug trays, 1 branch per cell; for sowing boxes, insert the branches so that the leaves do not cover each other and do not affect photosynthesis. The cutting depth is 2cm; do not insert too deep, so as not to affect rooting. After inserting, gently press the substrate surface with your hand.
2.2.4 Post-cutting management
After cutting, place the plug trays or sowing boxes under a shade net with a shading rate of 70% and in an environment at about 25 degrees C. According to weather conditions, spray water on the substrate surface every 2h on clear days; on cloudy or rainy days, spray less or not at all, keeping air humidity at about 80%. At the same time, there must be no water accumulation in the substrate. About 30d after cutting, new roots grow; gradually reduce the frequency of spraying. After the root system reaches 3cm, transplanting or potting can be carried out and normal management begins. At low temperatures, rooting is slower.
3 Management after potting
3.1 Potting
When the 3rd pair of true leaves has grown on sown seedlings or when the root system of cutting seedlings reaches 3cm, they can be transplanted into pots. The potting substrate can be peat and perlite mixed evenly at a ratio of 4:1. The disinfection method is the same as the sowing substrate.
3.2 Light management
Star flower prefers an environment with sufficient sunlight. With sufficient light, the plant becomes more compact and stocky. Therefore, in winter with weak light and short daylight, attention should be paid to supplementing light. Proper supplementary light can shorten the cultivation time by 2-3 weeks; if light is insufficient, the flower stems will become leggy. In greenhouse cultivation, shading is not needed in winter; in spring, summer, and autumn, shade 30%. Growth in a semi-shaded environment is also relatively ideal.
3.3 Temperature management
Warmth and sufficient sunlight help the growth of star flower. During the growth period, it is advisable to maintain nighttime temperatures above 17-18 degrees C and daytime temperatures above 22-24 degrees C; temperatures below 10 degrees C will cause uneven flowering and delay or hinder flower opening.
3.4 Water and fertilizer management
Star flower is relatively drought-tolerant but not waterlogging-tolerant. During the growth period, do not overwater, and at the same time avoid water accumulation in the cultivation substrate to avoid inducing root rot. Watering should follow the principle of not watering until dry, and watering thoroughly when watering. When watering, the water temperature should not be too low. Overwatering often causes plant yellowing and slow flower growth. For fertilization, the water-soluble fertilizer Peters 20-10-20 can be used. The fertilization concentration in the first month after potting is 0.20%, and from the second month onward the concentration is 0.30%, applied once every 7-10d.
3.5 Plant shape management
In order to obtain an ideal plant shape, it is generally necessary to pinch once at 3-4 pairs of true leaves, leaving 2 pairs of true leaves after pinching. After flowering, faded flowers should be cut off immediately, and fertilizer and water should be strengthened, which can promote the sprouting of new branches and continued flowering. When the lower branches and leaves of old plants are sparse, the ornamental value of the plant decreases, and a heavier pruning should be done to promote branching at the lower part of the plant and form a better plant shape.
4 Pest and disease control
Common pests and diseases of star flower include damping-off, gray mold, and whitefly.
4.1 Damping-off
Damping-off is likely to occur during the seedling stage. Affected seedlings suddenly lodge and die, affecting the survival rate of seedling raising, and may even destroy all seedlings. The disease mainly occurs after the seedlings emerge, when the base of the young stem is infected by pathogens. At first, the diseased part shows small water-soaked spots, then turns light brown to brown and becomes sunken and constricted. The diseased part rapidly develops around the stem for 1 full circle, causing the young leaves, while still emerald green, to lodge and die from the base, hence the name damping-off. Finally, the diseased seedlings rot or dry up. After sowing, from seed germination to emergence, they can also be infected, causing bud rot and seed rot, and missing seedlings and broken rows appear on the seedbed. When the substrate humidity is high, a layer of white flocculent mycelium can often be seen on the diseased seedlings and the nearby soil surface. Damping-off is mainly caused by Pythium. The pathogen overwinters in the soil or on diseased plant residues, has strong saprophytic ability, and can survive in the soil for a long time, and is called a soil inhabitant fungus. The pathogen spreads through irrigation water and rainwater, and can also spread through contaminated compost, seeds, etc. High soil moisture in seedbeds and sowing boxes, improper watering, oversowing, unsuitable temperature, and weak seedling growth all favor the occurrence of damping-off. Continuous cropping seedbeds or flower gardens are severely affected because of the relatively high accumulation of soil-borne pathogens. Damping-off is a typical soil-borne disease.
Control methods: (1) Improve seedling raising measures. Choose high, dry, well-drained terrain for the seedbed; apply fully decomposed fertilizer or use high-quality culture soil; control irrigation during the seedling stage, and the soil should not be too wet; sow at the proper time so that seedlings are not affected by unsuitable temperatures; do not sow too densely, and thin and transplant seedlings in time so that the seedbed remains well ventilated; avoid continuous cropping in flower gardens with severe disease, or disinfect the soil before sowing; implement excellent seedling raising measures and cultivate strong seedlings to enhance disease resistance and reduce the harm of damping-off. (2) Soil treatment. Because the damping-off pathogen can survive in the soil for a long time, directly eliminating the pathogen in the soil is of great significance for controlling the disease. Mix in 50% carbendazim wettable powder at 0.10% of the substrate weight respectively for substrate sterilization. (3) Chemical control. Spraying fungicides promptly at the early stage of the disease can effectively control the epidemic of the disease. Commonly used fungicides include 50% carbendazim wettable powder 500 times solution, 25% metalaxyl (Ridomil) wettable powder 800 times solution, 40% fosetyl-aluminum (Aliette) wettable powder 200-400 times solution, 75% chlorothalonil wettable powder 600 times solution, etc. Be careful to spray the young stems of seedlings and the central diseased plants and the diseased soil near them. Apply once every 7-10d, alternating chemicals, spraying continuously 2-3 times, or according to the disease situation. Generally, spray chemicals once each during the seedling stage and the early stage of potting management for prevention.
4.2 Gray mold
Gray mold can damage leaves, stems, flowers, and fruits. The symptoms are relatively complex, including leaf spots, cankers, seedling damping-off, and organ rot. Under humid conditions, the gray mold layer is obvious, and in severe cases the whole plant dies. When humidity is high, gray mold grows on the diseased parts. This disease relapses very easily, so the control of gray mold must be persistent. In maintenance and management, ventilation should be enhanced, watering controlled on cloudy days, nitrogen fertilizer applied less, and diseased flowers and leaves removed promptly; for chemical control, 50% procymidone wettable powder 2,000 times solution or 70% thiophanate-methyl wettable powder 1,000 times solution can be selected, applied once every 7-10d, alternating chemicals, spraying continuously 2-3 times, or according to the disease situation.
4.3 Whitefly. The body is small, white, and not strong in flight. Adults and larvae suck plant sap, causing affected leaves to turn yellow and fall off; the honeydew secreted by the adults can cause sooty mold. Control methods: use yellow sticky insect boards for trapping and killing. Yellow sticky boards can be placed in the greenhouse, and flowers can be shaken manually to trap and kill the startled whiteflies as they fly. 40% omethoate 1,000 times solution, or 2.50% deltamethrin emulsion 2,000 times solution, or 10% buprofezin 2,000 times solution can be sprayed once every 10d, continuously 3-4 times, which can achieve obvious results.
The above are all the cultivation key points for potted star flower. Flower farmers are welcome to download the Huinong APP to learn at any time every day, and interested flower enthusiasts are also welcome to refer to this site!
How to grow potted baby's breath: flowering period management of potted baby's breath
Baby's breath is a perennial herb that can be cultivated for ornament. So how much do you know about the cultivation methods for potted baby's breath? The following is the content we have compiled on how to grow potted baby's breath. We hope you like it!
Cultivation methods for potted baby's breath
1. Water and fertilizer management
Baby's breath bonsai should be watered frequently during the growing season to keep the pot soil moist. In summer, spray leaf surface water 1-2 times a day; in the rainy season, pay attention to checks, and avoid water accumulation in the pot. In winter, the number of waterings should be appropriately reduced, generally watering thoroughly once every 3-6 days (when the pot soil surface is slightly dry and turns slightly white). Each year before full bloom (that is, April-May), apply 2-3 times a phosphorus-potassium fertilizer solution at a concentration of 0.3%-0.5%. In the depths of winter, apply 1-2 times a thin organic fertilizer solution as a top dressing; fertilization is not suitable in other seasons. Avoid applying concentrated fertilizer.
2. Light and temperature requirements
Baby's breath is a subtropical tree species and dislikes strong direct sunlight; in summer it should be shaded 50%-70%. In winter, it can overwinter outdoors in the south; in the north it should be moved indoors, and the room temperature should preferably be kept at 5-12 degrees C.
3. Repotting and pruning
Usually repot and change the soil once every 1-2 years, carried out in spring from February to March or during late autumn. Replace all the old soil, properly prune the roots, and combine repotting with root lifting to form hanging roots and improve ornamental value. Each year from after half defoliation in winter to before sprouting the following spring, carry out one shaping and pruning, cutting short long branches and leggy branches, thinning overly dense fine weak branches, and cutting off diseased and insect-damaged branches and other messy branches that affect ornamental value; during the growing period, promptly pinch buds, remove buds, and remove branches to maintain a graceful shape. The healthy branches cut off can be used for cutting propagation.
4. Pest and disease control
Baby's breath bonsai has relatively few pests and diseases, with occasional occurrence of aphids and snails. Once they occur, timely and targeted control should be carried out. For severely affected plants, take them out of the pot, replace with new culture soil, wash the roots clean, cut off diseased roots, soak the roots in the above-mentioned chemicals for 30 minutes, and then replant in pots; generally the plants can be saved.
Ornamental uses of potted baby's breath
Use in flower arranging
Because baby's breath looks plain and does not attract attention, it has long been in a state of blooming and falling unnoticed. Only the girls of Tunisia, rich in olive trees, had a special fondness for it. By the early 19th century, many upper-class people in Europe started a craze for flower arranging art, which made more and more flower lovers fall in love with this "lady in the boudoir." Today, baby's breath has risen to become one of the world's top ten cut flowers, standing on equal footing with roses, tulips, carnations, and others.
Baby's breath is often used to decorate bouquets. Elegant and refined, it is a top-grade material for flower arranging as a cut flower, and after drying in the shade it becomes a natural added dried flower.
Baby's breath is an annual herbaceous plant with many branches on the stem and lanceolate leaves. Flowers bloom at the tips of each slender branch, numerous like stars in the sky, and the flower shape is very delicate and beautiful. In Western flower arranging, baby's breath is often regarded as "versatile," because it can be matched freely with various different types of flowers, does not steal others' elegance, and yet can timely show its own elegance and loveliness without losing its own style. This trait is not something other flowers can surpass!
Floral art creation
Baby's breath is generally used as a supporting material for the main flower and is often called the "bridesmaid flower." With its support, the main flower becomes even more brilliant. Just like supporting roles in a movie, only with the foil of supporting roles does the lead appear more vivid and full. The lead and supporting roles depend on each other and bring out the best in each other, so that the theme's ideas can be expressed most vividly. Using baby's breath as a foil can handle relationships in flower arrangement works such as weight, density, depth, concealment and exposure, bending and lifting, height, and distance, making the work more profound and the theme more prominent, fully displaying a sense of three-dimensionality, haziness, and fluffiness. For example, simply arranging a few rose branches can certainly express their beauty, but if a bunch of baby's breath is added, it can create an even stronger accentuating effect.
The snow-white, fluffy baby's breath flowers are extremely small and light, and in floral art are often used as a supporting role, paired with roses, campanula, and others to make a typical bouquet of love. In fact, appreciating baby's breath alone is also very distinctive. Tie it in bunches tightly as the main flower and put it in a vase, and you can immediately feel a relaxed and lively atmosphere. After natural air-drying, it can also be made into dried flowers; the whole plant can be dyed and pressed, offering more variations in use.
Purchasing key points: choose plants with snow-white flower color, buds without drying or yellow-brown phenomena, and flower stems emerald green and firm.
The flower language of baby's breath
Baby's breath is a flower loved by refined people, and has always contained the meaning of "pure, far-reaching, romantic."
Baby's breath flower language: care, longing, purity, true love, pure heart, joy, concern, purity, watching over love, and the love of being willing to play a supporting role.
[Flower language] Missing, pure, dream, true liking, supporting role, but indispensable
[Symbolic blood type] Type A
[Lucky zodiac sign] Virgo
[Representative zodiac sign] Capricorn
[Purchasing] It is best to choose flowers that are pure white, full, with few blind branches, and with fresh green, elastic stems.
[Cut flower lifespan] 8-12 days
[Gift recipients]
As a supporting material for Chinese rose to give to a lover, it can create a beautiful love story;
Paired with gladiolus to give to graduating classmates, it means "great prospects."
Flowering period management of potted baby's breath
September to December
After September, artificial electric lighting supplementation is needed to meet the long-day conditions for winter flower production, in order to induce flower bud differentiation and shift vegetative growth to reproductive growth. The method of all-night lighting or late-night lighting (from 22:00 to 2:00) is often used, and the light intensity should be guaranteed at 50-100 lux. Winter flower production also requires maintaining a temperature above 15 degrees. Low temperatures below 10 degrees easily produce rosette-like clustered leaves.
Temperature
Growth is best at a daytime temperature of 25 degrees C. If it exceeds 30 degrees C and the time or number of days is too long, the probability of deformed flowers increases. The nighttime temperature is best at 10-15 degrees C. If below 10 degrees C, combined with the short days of autumn and winter, it easily causes a dormant state or clustering.
Sunlight
For most commercial varieties, the critical photoperiod for flowering is about 12-18 hours. Long-day treatment itself only effectively induces the differentiation of flower spikes, while more long-day treatment can obtain more flowers. And a longer photoperiod not only promotes earlier flowering, but the flowers are also larger. As for Bristol Fairy's demand for long light, it is not as sensitive as other varieties such as Perfecta diamuna; it can flower with 12 hours of light. This is one of the reasons why this variety became the main variety for professional production in Taiwan, China.
Light intensity
Light has an extremely profound effect on whether baby's breath flowers, especially in winter when it is more obvious. If summer baby's breath is given 80-24Klux illumination, all plants can flower; the difference is that the less illumination the plants receive, the relatively fewer the flowers. In winter, plants given 58Klux can all flower; while those given 24Klux cannot flower even if continuously given a 24-hour full-light period.
Soil preparation
The roots rot easily. Generally speaking, slightly alkaline calcareous soil or gravelly loam with good drainage is best. Acidic or neutral soil should be appropriately treated with some lime to adjust the soil pH.
Before planting, the soil should be deeply plowed 40-50cm, sufficient organic fertilizer should be applied, and some phosphorus and potassium fertilizer should be appropriately added. Make high beds, with a bed surface height of 30-40cm.
Planting
Plant 2,000-2,500 plants per mu (1 mu = 667 sq m), using double-row planting, with a row spacing of 50cm and a plant spacing of 35-50cm. Before planting, irrigate fully, then choose a cloudy day for planting, and water thoroughly after planting. Planting time: For cut flower cultivation, if produced in a greenhouse, it can be planted in summer or autumn or even early spring. In this way, flowers are harvested from early autumn until early summer. After harvesting flowers, the plants should be dug up in June-July, then cold-stored until August-September, and then planted again.
Water
The seedling stage has a relatively high demand for water. After pinching, sufficient water and nutrients are still needed so that the plant can gradually shift from the vegetative growth stage to the reproductive growth stage, that is, enter the bolting stage (flowering stage). Until the small flower spikes emerge and the petals grow out, water should be slightly reduced to prevent a decrease in cut flower quality and stem strength, and also to promote more uniform flowering. Especially in the hot and humid summer season, whether water control is appropriate is often the main factor determining the success of baby's breath cultivation.
Water management must be strictly controlled; excessive wetness weakens growth, and water accumulation can cause root rot and death. When the plant grows to 30cm, watering should be controlled, especially during the bud stage, and it should be drier during the flowering period. In rainy areas, a shelter should be built to avoid rain during cultivation.
Fertilizer
Like other herbaceous flowers, baby's breath has a relatively high demand for fertilizer and water, but it is most afraid of random fertilization, concentrated fertilizer, and one-sided application of nitrogen, phosphorus, and potassium fertilizers. It is required to follow the two fertilization (water) principles of "apply light fertilizer frequently, small amounts and many times, complete nutrition" and "alternate dry and wet, dry thoroughly when dry, do not water until dry, water thoroughly when watering," and after fertilization, keep leaves and flowers dry at night. After planting, apply top dressing in stages, mainly nitrogen fertilizer in the early stage and mainly phosphorus and potassium fertilizer in the later stage.
Spring:
After the temperature rises, growth recovers rapidly and gradually enters the flower bud differentiation stage and flowering stage, with a high demand for fertilizer and water. Fertilizer and water management follows the cycle of "Hyponex" -> clear water -> "Hyponex" -- clear water, with an interval of about 2-4 days. After entering the seed-setting stage, stop fertilizer supply. Red and yellow baby's breath placed together
Autumn:
After the sown seedlings are potted and recover for a period, fertilizer and water management should be quickly brought up to speed. Fertilizer and water management follows the cycle of "Hyponex" -> "Hyponex" -> clear water -> "Hyponex" -> "Hyponex" -> clear water --, with an interval of about 1-3 days. On clear days or during high temperatures, the interval is shorter; on cloudy and rainy days or during low temperatures, the interval is longer or no watering is done.
Winter:
Although it continues to grow, the relatively low temperature slows its growth rate, and it does not require much fertilizer and water, and may even require fertilizer and water control. Fertilizer and water management follows the cycle of "Hyponex" -> clear water -> clear water -> "Hyponex" -> clear water -- clear water, with an interval of about 4-7 days. Try to arrange watering at noon on clear days when the temperature is relatively high.
Cultivation methods for Pentas lanceolata
Cultivation methods for Pentas lanceolata
Basic information on Pentas lanceolata
Scientific name: Pentas lanceolata
Aliases: Egyptian star cluster, star flower, star-shaped flower, umbrella flower, herbaceous ixora.
Family and genus: Rubiaceae, Pentas. Evergreen herb or subshrub, plant height 30-60cm. Stems upright or lower part prostrate, base woody. Leaves opposite, lanceolate or ovate, about 9cm long, hairy. The flowering period is mainly from autumn to winter, and it can also flower at other times; cymes terminal, flowers small, tubular, corolla 5-lobed and star-shaped, often dozens of flowers clustered into a mass, with colors such as light purplish red, blue-purple, white, pink, and red. Capsule. Seeds numerous, extremely small.
Pentas lanceolata has small flowers but blooms profusely, with a long flowering period. Under suitable conditions it can bloom continuously in all four seasons, with flowers like stars filling the sky and also like small opened umbrellas, delicate, exquisite, and gorgeous; it is robust by nature and easy to propagate. It is a flower type very suitable for cultivation on balconies and windowsills.
[Pentas lanceolata propagation] Cuttings, sowing. Mainly by cutting propagation.
(1) Cuttings: carried out during the growing period, with April cuttings being the best. Select non-flowering branches and cut them into cuttings 6-8cm long, with 2-3 nodes, and slightly including second-year growth.
After cutting, keep the substrate and environment moist, and shade 50%-70% of sunlight. Roots can form in about 20 days, and survival is very easy. If cuttings are soaked in 0.1%-0.2% indoleacetic acid for 2-3 seconds, rooting time can be shortened. Cuttings can also be taken in autumn.
(2) Sowing: carried out in April. Because the seeds are small, they need to be mixed with fine sand before sowing. The suitable germination temperature is 21-24 degrees C. After sowing, keep the bed soil moist and the relative air humidity relatively high. Germination occurs after 14-21 days. From sowing to flowering takes 16-22 weeks.
[Key points for cultivating Pentas lanceolata]
(1) Temperature: It prefers warmth and can continue growing and flowering above 15°C, with an optimum growing temperature of 20-30°C. It is not cold-tolerant; when the temperature drops below 10°C, the plant enters dormancy, and it should be kept above 10°C for overwintering; below 5°C it will drop its leaves and die. It is tolerant of high temperatures and can grow and flower normally under slightly shaded conditions when it is hot.
(2) Light: It likes sun and is sensitive to light. During the flowering period it needs 80%-100% sunlight, which favors vigorous growth and flowering. There should be more than 4 hours of direct sunlight each day; too much shade will cause the branches to grow leggy, the plant to become weak and spindly, the leaves to turn yellow, and flowering to be difficult or poor. However, when the summer sun is strong, proper shading is needed; too much light can also make the plant difficult to flower. At other times, give it plenty of sunlight. Still, try to let it receive morning and evening sun, and shade about 30% of the sunlight.
(3) Watering: It fears drought and likes a moist soil environment. During the vigorous growth and flowering period and in summer, water should be supplied generously to keep the potting soil moist. However, waterlogged potting soil must be avoided, and watering during the growing period should follow the principle of "alternating dry and wet." After rain during the plum rain season, check promptly and pour off any accumulated water in the pot. In winter, watering should be controlled, especially since there is a dormant period of about 1 month after flowering in autumn and winter; watering must be restrained, and it is enough to keep the potting soil slightly moist.
(4) Environmental humidity: During the high-temperature period in summer, if the weather is clear and dry, water should often be sprayed on the branches, leaves, and surroundings to increase the relative air humidity, which benefits the plant's growth and flowering.
(5) Fertilizing: During the growth and flowering period, a fertilizer combining nitrogen, phosphorus, and potassium should be applied once every half month to support continuous growth and flowering. Because it is highly adaptable and grows quickly, too much nitrogen fertilizer should not be applied, otherwise the plant will grow leggy and flower sparsely, affecting its ornamental value. Fertilizing should be combined with pruning, that is, after each flowering, remove the spent flowers and promptly replenish fertilizer to promote the sprouting of new branches and continued flowering. During overwintering, if a temperature above 15°C can be maintained and the plant continues to grow and flower, continue applying fertilizer once every half month; if the temperature is low and the plant enters dormancy, stop fertilizing.
(6) Pruning: During the seedling stage, when it grows to about 10 cm, pinch out the growing tips to encourage branching and more flowers. Pinching should be done on a sunny day; pinching during continuous rainy weather easily causes the wounds to rot. During the growing period, overly long branches should be cut back at any time. If seeds are not being saved, the branches and leaves may be pruned moderately after flowering, and the spent flowers cut off to avoid consuming nutrients, which can keep the plant compact and promote new buds and continued flowering.
(7) Potting and repotting: When the seedlings reach 15-20 cm tall, plant them in pots with a diameter of 15-20 cm. Repot once every 1-2 years, preferably in spring or autumn. It likes fertile, loose, well-drained, slightly acidic soil, with a pH of 6.0-6.5 being best. The growing medium can be prepared from materials such as peat soil, leaf mold, garden soil, and coarse sand. After 2-3 years in a pot, the plant's vigor declines noticeably, so it should be discarded and replaced.
(8) Pest and disease control: It is harmed by pests and diseases such as leaf spot disease and whiteflies.
[Common problems in growing and caring for Pentas]
Common problem Cause
The plant is thin and spindly, the leaves are withered and yellow, and it does not flower or the flowers are small and few 1) Insufficient light; 2) Lack of fertilizer; 5) The plant has grown for many years and its vigor has weakened
The branches and leaves are large and thick, but there are few flowers This is due to applying too much nitrogen fertilizer or applying only nitrogen fertilizer