Characteristics of the tunbergia plant, how to plant and care in the open field, breeding rules, fight against diseases and pests during cultivation, curious notes for gardeners, species.
Thunbergia is a representative of such a large family as Acanthaceae. These plants are found in natural conditions in areas where tropical and equatorial climate prevails. Such areas on the planet are the areas of the African continent, the southern regions of Asia, as well as the islands of Madagascar. The genus has approximately two hundred species. In our latitudes, tunbergia are excellently grown in gardens as annuals, or you can cultivate them in rooms.
| Family name | Acanthus |
| Growing period | Perennial or annual |
| Vegetation form | Herbaceous |
| Breeds | Mostly by seeds, but grafting can also be done |
| Open ground transplant terms | In late spring (after the 20th of May) |
| Landing rules | Planting of seedlings is carried out at a distance of 40-45 cm from each other |
| Priming | Light, nutritious, well-drained, lime-laden |
| Soil acidity values, pH | 6, 5-7 (neutral) |
| Illumination level | Place with diffused lighting, partial shade |
| Humidity level | Regular watering, but moderate, abundant during flowering and drought |
| Special care rules | Provide stalk garters and fertilizers |
| Height options | 2-8 m |
| Flowering period | July to late August |
| Type of inflorescences or flowers | Single flowers or in bundle-shaped inflorescences |
| Color of flowers | Snow-white, blue, blue, violet, lilac, crimson, yellow, orange, brown, sometimes red. Heart is dark, brown or black |
| Fruit type | Seed capsule |
| The timing of fruit ripening | In autumn |
| Decorative period | Summer-autumn |
| Application in landscape design | In vertical gardening and as a tapeworm on the lawn |
| USDA zone | 5 and higher |
The genus of these representatives of the flora received its name in honor of the "father of African botany", a scientist from Sweden Karl Peter Thunberg (1743-1828), who devoted his research to the flora and fauna of the South African and Japanese territories. Because of its bright and spectacular flowers and an inner dark "eye", Tunbergia was nicknamed "black-eyed Suzanne" in Europe.
The plant can have both a perennial and an annual growing season. Usually characterized by liana-like outlines of the stems, but in rare cases, if climatic conditions permit, they grow in the form of evergreen shrubs. The height usually varies within 2–8 m. The color of the surface of the stems is greenish-gray or grayish-beige, but young shoots are often greenish, but often all the stems are hidden under a lush deciduous mass.
The foliage on the stalks of tunbergia is alternate or can grow in the opposite order. The sheet plates have solid contours or are divided into blades. There are species whose leaves resemble a triangle or have an ovoid shape with an elongated tip. The base of some tunbergia leaves is heart-shaped. There are species that have teeth along the edge. The foliage is characterized by pubescence. The length of the leaves of "black-eyed Suzanne" varies from 2.5 to 10 cm. The deciduous mass is painted in a rich green or emerald color.
Flowering that takes effect from mid-summer and can stretch until the first days of autumn. Then, along the entire length of the stems, on the branches of the current year, the tunbergia forms bright funnel-shaped flowers. Flowers, sitting on elongated pedicels, are characterized by bisexuality, they originate from the leaf sinuses, while the buds are located both singly and can be collected in bundle-shaped inflorescences. The flowers do not have a cup (it is greatly reduced), its role is shifted to the bracts extending from the peduncle. The petals of the bracts can completely cover the flower bud. The corolla tube of the tunbergia flower ends in division into five petals, which can grow spaced apart or overlap each other.
The petals are painted in snow-white, blue or blue, purple or lilac, crimson or yellow, orange or brown, but there are specimens with a red color scheme. The inner part of the funnel of tunbergia has a "eye" of brown, black color, for which the plant is nicknamed "black-eyed Suzanne", but in some species, with the purple color of the petals, the core is yellow. Inside the corolla there are two pairs of stamens, on which the anthers have formed a longitudinal slit with pubescence around the circumference. It is this that contributes to the retention of pollen. When flowering over the plantings of tunbergia, a strong intoxicating aroma spreads, but not all species can "boast" of this.
Tunbergia flowers are pollinated by insects, while some species are pollinated exclusively by carpenter bees of the genus Xylocopa. The fruit is a two-celled capsule filled with seeds. At the top, it is beak-shaped. The diameter of the seeds is only 0.4 cm. Their color is grayish-brown, the shape is compressed to rounded, but there is a hole on one side. They have no protrusions (trichomes) or pubescence.
The plant, although simple to care for, but in our latitudes you can enjoy the flowering of tunbergia only in the warm season, and with the arrival of autumn, the entire aboveground part will die, even in a mild climate, and in the spring you will have to grow new specimens. But even this will not become an obstacle, since the "black-eyed Suzanne" becomes a real decoration in the garden.
Tunbergia: rules for planting and care in the open field
- Landing place "Black-eyed Suzanne" should be selected light, but with a slight shade in the midday hours. This is because burning direct sunlight can damage the foliage and delicate flowers of the tunbergia. You should not plant in places where groundwater is nearby, as this can provoke rotting of the root system. In this case, you should organize a "high flower bed". Also, the location for planting should be protected from gusts of wind and drafts, since this representative of the flora is thermophilic.
- Soil for tunbergia it is worth choosing light and nutritious, characterized by good drainage, preferably with an admixture of lime. You can make a soil mixture from turf soil, humus and coarse sand in a ratio of 2: 2: 1 or leaf and turf soil, peat chips and river sand in a ratio of 2: 2: 1: 1. In any case, the acidity of the substrate should be in the range of pH 6, 5-7, that is, be neutral. Before planting, a small amount of lime or dolomite flour should be mixed into the soil mixture.
- Planting Tunbergia held in spring only when the threat of return frosts recedes. In some regions, this time falls in mid-late May, but there are territories in which the "black-eyed Suzanne" is planted in the beds not earlier than June. The distance between the planting holes is kept about 40–45 cm, since the vine can grow. If you want the stems to be used as vertical gardening in the future, then a trellis or a decorative ladder is installed next to the hole, to which the growing shoots can be tied. If the soil on the site is wet, then it is recommended to lay a layer of drainage material - expanded clay or fine gravel in the hole before installing the tunbergia seedling. After planting, the soil is carefully squeezed to remove all air voids and the soil is moistened next to the plant.
- Watering when caring for tunbergia, it is recommended to be regular, but moderate, only when the top layer of the soil begins to dry out. When flowering begins, the "black-eyed Suzanne" should be watered more abundantly. If the liana does not have enough moisture during this period, then not only the newly formed buds and open flowers will be dumped, but even the leaves. The same rule applies to dry and hot weather, then humidification is needed once or twice a week. During such periods, in the evening hours, sprinkling with warm water of the deciduous mass of the plant can be performed.
- Fertilizers when growing tunbergia, they will contribute to the growth of the number of leaves and the splendor of the flowering. Top dressing for leaf growth should be applied once a week. If there is a desire to get a lush green bush, then nitrogen-containing compounds are used (for example, azotofomka). However, such fertilizers will negatively affect subsequent flowering. It is better to use mineral preparations intended for flowering garden plants (for example, Kemir or Fertik). Such funds are applied twice a month, when the first buds appear on the stems until the very middle of autumn.
- Pruning contributes to the formation of beautiful outlines of the crown of Tunbernia. Young shoots should be pinched regularly. If the plant is grown in a room, then the stems are gradually exposed and their length should be shortened.
- General advice on care. In order for the bush to remain decorative for a long time, it is recommended to remove drying branches and wilted flowers. Shoots should be periodically directed in the direction that contributes to a more beautiful crown outline.
- Collecting Tunbergia Seeds should be carried out as the flowering progresses, since seed pods will gradually form in place of flowers. If the collection is not carried out, then the fruits will open and all the seeds will be on the surface of the soil. When the boxes are cut, they are brought into the room and laid out on a sheet of clean cloth or paper. Drying should be done in a well ventilated area. When the fruits are dry, they are opened, the seed is poured into paper bags and stored in a dry and dark place. Seeds do not lose their germination for two years.
- Wintering. A plant such as tunbergia is also thermophilic in regions with mild winters, especially in our latitudes, the entire above-ground part will suffer. Therefore, with the arrival of autumn, all stems and roots should be removed in order to plant again with the arrival of spring. If you do not want to part with the "black-eyed Suzanne" bush, then you can transplant the vine into a pot with suitable soil. Then in the fall, the stems are cut, trying to leave 4–5 buds on them. All sections must be processed for disinfection with a solution of potassium permanganate. Thunbergia during the winter months should be kept in a room with a heat reading of about 15 degrees and good lighting. Care will consist in periodically moistening the upper layer of the substrate, but here it is important not to pour it, but only to moisten it a little. In the spring, you can plant the plant again in open ground.
- The use of tunbergia in landscape design. The black-eyed Suzanne plant is quite spectacular and can become a wonderful decoration of the garden. In addition, thanks to the high-growing stems, you can arrange the posts of arbors and pergolas, decorate balconies and stairs.
See also tips for growing acanthus outdoors and at home.
Breeding rules for tunbergia
To grow on the site the bushes of "black-eyed Suzanne", you can use sowing seeds. To do this, it is recommended to sow seed directly on a dedicated area in open ground or to grow seedlings.
Reproduction of tunbergia by growing seedlings
For this purpose, in the last days of February, purchased seeds are sown. This is because in our latitudes there is no way to get them, since the plant lacks the duration of the warm season. Before sowing, it is recommended to soak the seeds for half an hour in any growth stimulation solution (for example, Kornevin, Radonite or Agrolife). After that, sowing is carried out in seedling boxes, in which a light and nutritious substrate is laid (you can use a purchased seedling mixture or combine peat chips and sand in equal volumes). The seeding depth of tunbergia seeds should be no more than 5–7 mm. Watering on top is recommended using a fine-dispersed spray gun, since a watering can stream without a sprinkler head can easily wash crops out of the soil.
The seedling container should be covered with plastic transparent wrap or a piece of glass should be placed on top. This will help create a greenhouse environment. The place where the box with crops is placed should be well lit with a temperature of about 22-24 degrees. Only after 3–7 days will it be possible to see the first shoots of tunbergia, the shelter at this time can already be removed. It is recommended to lower the heat indicators to a mark of 18 degrees, so that young stems do not stretch up very much.
When 3-4 true leaf plates appear on the seedlings, it will be necessary to carry out thinning, maintaining a distance between the plants of 15 cm. Some gardeners dive at this stage seedlings in separate pots in order to subsequently transplant into open ground. To make this operation easy in the future, it is recommended to use containers made of pressed peat, then the tunbergia seedlings can be lowered directly with a pot into a dug hole in a flower bed.
Only when the height of the seedlings of "black-eyed Suzanne" is equal to 12-15 cm, then it is necessary to pinch the tops of the stems to stimulate branching, as well as the splendor of flowering, since the buds are formed on the shoots of the current year. If it is decided to get a dense and powerful green mass of tunbergia, then the seedlings after the picking should be fed once every seven days with fertilizers, with nitrogen in the composition (nitroammophos or azofos). But if you wish in the future to enjoy the lush flowering, stretched out for a long period, then feeding the seedlings is not recommended at all.
Advice
Some flower growers, in order not to engage in picking of tunbergia seedlings, immediately sow in separate cups, placing three seeds in each.
After only 3, 5–4 months from the moment of sowing, it will be possible to enjoy the lush flowering, stretched out for the whole summer.
Reproduction of tunbergia by cuttings
This method can be used when the plant is grown indoors. In the spring, you can cut blanks from the bush of "black-eyed Suzanne". The length of the cutting should be at least 10 cm. For success, before planting, the sections of the branches can be dipped into a root formation stimulator (for example, heteroauxinic acid or Epin are used). Tunbergia cuttings are planted in separate small cups filled with a peat-sandy composition.
A plastic bottle with a cut-off bottom is placed on top, you can take a glass jar or just wrap the seedlings with plastic wrap. All this is done to increase the moisture content during rooting. When leaving, you should ventilate and water the soil every day if its top layer is dry. When young leaves begin to unfold on a young tunbergia plant, this is a sign of successful rooting. But the transplant should be carried out next spring, since with the arrival of autumn, the entire aerial part dies off.
Read also the rules for the propagation of a trillium flower
Disease and pest control when growing tunbergia outdoors
The plant "black-eyed Suzanne" shows a fairly high resistance to diseases and harmful insects that affect many garden plantings. However, when the rules of agricultural technology are violated, the attractiveness of tunbergia rapidly decreases, since with stagnant moisture in the soil, root rot can occur, and the wrong planting site (in too thick shade) will lead to stretching of the stems, reduced growth, the leaves become faded, and there are practically no flowers is revealed.
With root rot (the disease can be provoked by various fungi), the symptoms of tunbergia can resemble severe drought. The leaves become drooping, their color fades, acquire a yellowish or brown tint. If you do not recognize the disease in time, but begin to water the bushes, this will lead to the rapid death of the plant. In order to accurately determine the disease, it is recommended to dig up the soil to a depth of about 15 cm and inspect the root system. If the soil in such a place is waterlogged, and the roots have become softened, acquired a black color and emit an unpleasant odor, then the presence of root rot is evident. You can try to start treatment, although in most cases this does not give positive results. Usually, all plantings of tunbernia are treated with fungicides, like Fundazol. If the lesion has gone far, then it is recommended to remove all affected specimens so that they do not infect other garden plants.
But it is best not to lead to the occurrence of fungal diseases on tunbergia, you should adhere to the following rules:
- when planting, select a lightweight substrate, the water in which will not be able to stagnate;
- when planting bushes, drainage, coarse sand or expanded clay must be used;
- with the proximity of groundwater, planting tunbergia in high beds;
- do not violate the rules of watering.
If we talk about pests, then when the weather is too dry and hot, it happens that the bushes of "black-eyed Suzanne" become a victim spider mite or whitefly … You can identify harmful insects by the following criteria:
- with the appearance of a thin cobweb, punctures on the edge of the leaf plates, their yellowing and discharge, we can talk about the presence of ticks;
- having found numerous white dots on the leaves on the back side, as well as small white midges that begin to swarm at any touch of the stems and foliage, then these are symptoms of the presence of a whitefly.
Both pests tend to leave behind a sticky sugary bloom - honeydew, which is a waste product of insects. If you do not carry out a timely fight and destroy them, then such a plaque becomes the cause of such a disease as a sooty fungus. To get rid of insects that have settled on tunbergia, you can use both folk remedies and industrial insecticides.
From the folk, solutions based on laundry soap or any other soap can be distinguished, from the purchased ones you can take the well-proven Aktara or Aktellik. After spraying the tunbergia bushes, it must be repeated ten days later in order to get rid of the hatched and remaining eggs. Treatments are carried out with the indicated break until the pests are completely destroyed.
Curious notes for gardeners about Thunbergia
It is interesting that there are species in the genus "black-eyed Suzanne" that are grown as an ornamental crop not only because of the flowers themselves (for example, such as Gregor's tunbergia), but also their popularity was influenced by the almost continuous process of opening the buds throughout of the year.
It is also important that for a long time in the territories of natural growth, some species, such as, for example, Thunbergia laurifolia, were familiar to medicine men for their medicinal properties. The extract obtained from the plant today has been confirmed by scientific research in preclinical experiments, the following actions are antioxidant, hepatoprotective and tonic of the central nervous system, as well as antidiabetic. In traditional Malay medicine, the juice of this plant was used to get rid of menorrhagia (menstrual bleeding), helping to heal difficult-to-heal wounds on the skin.
Due to these properties, laurel tunbergia was used not only for medicinal purposes, but local women used it by introducing it into cosmetic products (masks and lotions). They say that even loose skin took on a fresh and blooming appearance under the influence of such funds, filling with inner strength and light. Poultices helped to eliminate age spots, which was actively used by elderly women.
And although official medicine has not confirmed data on clinical experiments in eliminating poisoning caused by the toxic effects of drugs, but in Thailand, tunbergia laurel juice is actively used for intoxication of any type, as well as the consequences and dependence on alcohol and drugs. In Russia there is a registered dietary supplement (dietary supplement) called "Getax", which includes this type of "black-eyed Suzanne".
Description of the species and varieties of tunbergia
Thunbergia eberhardtii
It occurs naturally in dense forests at an altitude of 300–800 m above sea level, in Vietnam (Hainan). The stems resemble vines of grapes and can be up to 12 m long, lignified. Shoots are 4-angular, furrowed, pubescent, pubescence is also present in the nodes. The petiole is 3-4 cm long. The leaf blade is wide, ovate-lanceolate, about 10x5 cm in size, both surfaces are bare. Finger-5–7-venation is present, the base is cordate, the edge is sparsely toothed or sometimes whole, the apex is pointed to sharp.
When flowering from August to November, flowering pubescent stems grow. Bracts of Tunbergia Eberharti are lanceolate, pubescent, 1-3-veined, dentate margins, sharp apex. The wrappers are ovate-lanceolate, with parameters 1–1, 4x0, 8–1 mm, the surface is felt, the apex is pointed. The calyx is annular, unlocked. Corolla up to 2 cm; the tube is yellowish brown; the lobes are ovate-elliptical, with approximately the same length of 1, 1 cm, the lower lobes are red, the upper ones are yellow. The shell of the anthers is bare, at the bottom pair of stamens with long spurs at the base, at the top pair of stamens at the base there is only one shell per anther. The ovary is pubescent.
The fruit of tegbergia eberharti is a capsule, with a diameter of 1–1.5 cm, the beak at the apex reaches 1.6 cm. Seeds are hemispherical, drooping. In nature, fruits ripen in the period January-April.
Winged tunbergia (Thunbergia alata)
Grown in gardens and naturalized along the roads. The area of natural growth falls on African lands, but is found in the Chinese provinces of Guangdong and Yunnan. Widely cultivated and naturalized in tropical regions. Herbaceous vines. Stems ± 4-sided to flattened, double-grooved, pubescent. The petiole is 1.5–3 cm long, winged, rarely pubescent. The leaf blades are arrow-shaped, deltoid and ovoid. Their size is 2–7, 5x2–6 cm. The surface is hairy, rarely furrowed, 5-veined palmate. The base of the leaves is cordate, the edges are whole or wavy, the apex is sharp.
When flowering in winged tunbergia, flowers originate from the leaf sinuses, are located singly. Flowering occurs in nature during the period from October to March. Pedicel is 2, 5–3 cm, sparsely furrowed. Bracts are ovate, their size is 1, 5-1, 8x1-1, 4 cm, the surface is prickly, 5-7-veined, the apex is sharp, pointed or obtuse. The calyx of the flower is annular, irregularly 10–13-lobed. Corolla orange with dark purple glandular "eye" in the throat. Corolla length 2, 5–4, 5 cm; the tube is mainly cylindrical by 2–4 mm, the neck is 1–1.5 cm; the lobes are ovoid and appear to be cut off.
Filaments of winged tunbergia flower 4 mm long, glabrous; anthers 3, 5–4 mm, unequal, pubescent along the edge and at the base. The ovary is bare; its length is 8 mm. At the stigma, the shape is funnel-shaped, unevenly two-lobed, the lower lobe extends, the upper lobe is straight. The fruit is a capsule with a pubescent surface. At the base, its size is 7x10 mm, 2-toothed; the beak is 1.4 cm long and 3 mm wide at the base. Seeds are reticulate on the dorsal surface. Fruits ripen in the period from February to May.
The best varieties of winged turbine are recognized:
- Blushing Sussie flower petals which have pastel shades of peach or cream color scheme.
- Sussie Orange flaunt with bright orange petals surrounding the dark center.
- African Sunset the flower contains petals of a bright terracotta shade and a "eye" of a dark tone.
- Sussie Weib this variety is characterized by the snow-white color of the petals.
- Thunbergia gregorii is a group of up to 15 different varieties, the main difference of which is the absence of a dark "eye" in the central part of the corolla. The petals in the flowers take on a wide variety of shades of orange.
Thunbergia grandiflora
is a plant naturalized in tropical regions around the world. The area of natural growth falls on the lands of China (Fujian, Guangdong, Guangxi, Hainan, Yunnan provinces), India, Myanmar, Thailand and Vietnam, at an altitude of 400-1500 m above sea level it can grow in thickets. Liana-shaped shoots usually reach a height of 10 m or more, woody. Stems are rectangular, furrowed, pubescent. The petiole is 1–7 cm, furrowed, pubescent. The leaf plate is ovoid or triangular-ovate, its size is 5-10x4-8 cm, thin, both surfaces are pubescent. On the surface of the leaves of this type of tunbergia, there are palmate-3–7-veined, the base is linear-subulate, the edges are wavy, irregularly angular on the main half or rarely intact, pointed at the apex.
Flowering occurs in the period August-January in natural conditions. Flowers of tunbergia large-flowered grow solitary, paired in leaf axils or located in inflorescences-clusters with 2–4 flowers per node; pedicels 4–7 cm, furrowed, pubescent. The peduncle is pubescent. The bracts are oblong-ovate, 2, 5-4x1, 5-2, 2 cm, both surfaces are pubescent, 5-7-veined, the base is shortened, the edge is full or ciliary, the apex is sharp with short mucus.
Calyx length about 2 mm, annular, not taut, densely pubescent. Corolla of tunbergia large-flowered bluish with yellowish throat, 4–6 cm, glabrous outside. The tube is mostly cylindrical and 3 mm wide and 7 mm long, then gradually widens to a 5 cm circumference in the throat. The lobes are ovoid, with parameters 3x2, 5 cm. Filaments are continuous, 7–9 mm; pubescent anthers. Ovary glabrous, with 2 equal lobes. The fruit is a capsule 1, 2–1, 5 cm long, pubescent, part of the base is 1, 3–1, 8 cm in diameter, the beak at the apex measures 2.5 cm. Seeds are ovoid, compressed, ripen in nature during November-March …
Thunbergia fragrans
grows in thickets and on the sides at an altitude of 800-2300 m. The territory of natural distribution is in China (Guangdong, Guangxi, Guizhou, Hainan, Sichuan, Taiwan, Yunnan), as well as Cambodia, India, Indonesia, Laos, the Philippines, Sri Lanka, Thailand and Vietnam. Shoots are vine-like, herbaceous. Stems almost 4-angular to flattened, furrowed, hairy. The petiole is 0.5–4.5 cm thick. The lamina is oblong-ovate or ovate, or varies from broadly ovate and oblong-lanceolate to lanceolate.
The size of the leaves of fragrant tunbergia is 3-14 x 1, 8-7 cm, both surfaces are densely pubescent, rarely bare. The shape of the leaves is finger-3–5-veined, the base is rounded to wedge-shaped or cordate, the edges are intact, irregularly twisted or finely toothed, coarsely toothed, the apex is sharp. Flowering in nature occurs in the period from August to January. Flowers are formed singly in the leaf axils. Pedicel 1, 5–5, 5 cm; bracts are ovate, their parameters are 1, 5–2, 5x0, 8–1, 5 cm, the apex is sharp.
The calyx of a fragrant tunbergia flower is 3–5 mm long, irregularly 10–17 dentate, glabrous. Corolla white, 3–5 cm. The tube is mainly cylindrical by 4–7 mm, the neck is 1, 8–2, 3 cm; lobes ovate, 1, 3–2, 5x1, 5–2, 3 cm. There are stamens, crowning filaments reaching 6–10 mm in length, naked. Anthers size 3 mm, glabrous. The ovary is also bare, its length is 1.5–2 cm, protruding. The stigma is funnel-shaped, reaching 2 mm. The fruit is a naked capsule, its size is 7x10-13 mm, the beak is measured from above 1, 5-1, 9 cm. Seeds are 4-5 mm in diameter, smooth or with scales on the surface. Capsules ripen in nature during November-March.
Variety differences in leaf shape, size, pubescence and marginal shape of the leaves of Thunbergia fragrans are extensive, and taxa have been recognized based on these characteristics.
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Video about growing tunbergia in open field conditions:
