Description of the exakum. Recommendations for planting seeds, care, reproduction and control of major pests and diseases. Exacum (Latin designation - Exacum) is a genus of herbaceous plants that are part of the large family Gentianaceae, known among amateur gardeners as gentian. The exakum lives in the Southeast of the Asian region and the lands of the Malay archipelago. Some species can be one-, two- or perennial, but they all have some common features, namely, an erect stem and lanceolate leaves. The delicate small flowers are usually blue or lilac, but purple varieties are rare. They are collected in small, few-flowered brushes and spread a strong pleasant aroma.
Exakum description
All representatives of the genus Exakum have a roundish shape and stretch upward within 15-30 centimeters. In home floriculture, the cultivation of annual plants is mainly practiced, giving many beautiful blue flowers in a bright saturated shade. Ekzakum is quite unpretentious to conditions, therefore, in addition to beautiful flowers and a pleasant aroma, there is also a relative ease of caring for it.
But this applies exclusively to annuals. When trying to grow perennial species of exacum, you will have to worry about providing them with an appropriate climatic regime, especially in winter, since the plant reacts extremely negatively to cooling.
Types of exakum
More than 30 different species of this plant have already been found and described in the natural environment, however, only Exacum affine is suitable for home floriculture. According to scientific data, for the first time it was discovered on one of the islands of the Indian Ocean - on about. Socotra.
In flower shops it is a herb and its seeds are sold under the name Exakuma related. It grows up to 25-30 cm in height and has highly branched erect stems with many processes and small internodes. The arrangement of the leaves is opposite, and they grow within 3, 5–4, 5 cm. The shape of individual smooth leaves is wide, ovoid, and they are formed on short thick petioles.
Thanks to the light veins (one central and three lateral) of a bright green shade, the leaves look very impressive. In summer, neat flowers with a diameter of 1, 5–1, 8 cm are formed at the top of each of the shoots. They spread a pleasant aroma, and the symmetrical shape with 5 petals and a flat corolla pleases the eye. The hue of exacum related flowers can be white, blue, purple, or lilac. It depends on the variety purchased and grown. The central part of each flower exhibits a dense and shortened anther, which has a rich yellow hue, which always creates an interesting contrast with the color of the petals.
For outdoor cultivation in botanical gardens and zoos in southern countries, it is quite rare, but still another type of exacum is used, which is called a three-vein. In Latin, it is designated as Exacum triverve. It was first discovered in Sri Lanka. It is a beautiful perennial plant, stretching half a meter in height, with a straight and branched stem. On it are glossy dark green leaves with 3 veins, as well as 5-petal flowers with yellow anthers.
Indoor Exacum Care
Since the plant is accustomed to the hot subtropical and tropical climate, it will have to provide the appropriate level of illumination, humidity and temperature conditions. It is not difficult to create the necessary conditions, after which the exacum will not require any special care and will soon delight you with beautiful flowers with a strong heady aroma.
- Lighting. Decorative exakum does not tolerate both excessive illumination and its lack. Therefore, the issue of light is always very acute. If you ignore it and do not provide the proper level of illumination, then exacum affine may not bloom at all. A particular difficulty with the intensity of illumination can arise in the winter. It cannot be solved simply by placing the plant on the windows of the southern, southwestern or southeastern directions. A short winter day in temperate latitudes will not be sufficient for the exacum to develop normally. Moreover, due to a lack of light, elongated weak shoots grow, on which stunted leaves of small sizes are formed. Cuttings taken from such plants for propagation will not take root well, complicating the propagation process. In this regard, in the late autumn and winter period, it is necessary to increase the daylight hours to 12 hours. For this purpose, fluorescent lamps are usually used, which are located in the immediate vicinity of the exacum (the approximate distance is 25–35 cm). You should not try to replace them with simple ones, since in such a case the intensity of light output will be worse, and the high temperature of standard incandescent lamps can cause damage to the sheets. In the summer, the exakum has enough ordinary sunlight, provided that the plant is on windowsills that face the east or southeast side. But it must be borne in mind that an acute shortage of lighting is felt in the first half of the day. At lunchtime, when the intensity of solar radiation reaches its climax, the exakum needs to be shaded. If this is not done, then its delicate leaves will suffer from overheating, as a result of which their elasticity decreases many times. This is due to an increase in the intensity of moisture evaporation under the influence of heat, as a result of which the plant is forced to leave more water to the root system and take it from the leaves. Seeing the weakened leaves, many rush to water them immediately. In no case should this be done, since there may be more than enough moisture in the soil, the roots simply cannot cope with its consumption. In this regard, the exakum first needs to be removed from the sun and placed in a cool place, where it usually quickly comes to its senses.
- Temperature. Despite the fact that tropical climatic zones are the homeland of the plant, the decorative type of exacum is not adapted to hot weather. He likes the usual room temperature within 20 degrees. If the plant is planned to be planted for more than one year, then for the winter period it is desirable to provide a lower temperature at the level of 14-18 degrees. During the summer season, it is useful to expose the exacum to fresh air, where it grows much better. In an apartment, you can take it out onto the balcony, which ideally should face the northeast or east.
- Air humidity to grow exacum, it must be kept at a very high level by spraying the leaves daily or providing the plant with a special moisturizer. In this case, it is necessary to control the ingress of moisture in order to exclude the possibility of accumulation of water inside the flowers. A simple alternative way to create a microclimate with a sufficient level of air humidity can be to place a flowerpot inside a container with expanded clay. But at the same time, you need to ensure that water does not penetrate into the plate with the pot, otherwise, as a result of an excess of moisture, the exacum can get sick and die.
- Watering. In spring and summer, when the plant first prepares for the flowering period, and then, in fact, enters this phase, you need to intensively water the soil, preventing it from drying out. Otherwise, the exacum may not bloom for a long time, and the leaves and shoots may become thinner and weak. At the same time, at no time should water be allowed to stagnate in the ground, as this leads to decay of the root system. At the same time, dangerous symptoms usually do not appear immediately, therefore, in some cases, the plant can no longer be saved. In winter, watering is reduced to a minimum. Usually, after the earth has dried up, it is allowed to stand like this for a day or two, and only then it is moderately watered. But here you should also take into account the location of the flowerpot. If it is close to heaters or the room temperature is above 18 degrees Celsius, the exakum may need to be watered more frequently.
- Top dressing. It is worth applying fertilizers only during active growth and flowering, that is, during the period from March to September. In no case should you be zealous with feeding, since Exakum reacts negatively to overdose. Usually it is carried out 1-2 times a month, using the usual fertilizer for indoor flowers. A commercially available liquid fertilizer can be applied before the flowers appear. If you dilute it not in accordance with the recommendations, but make a less concentrated solution, then you can feed the exakum once a week, which will give a good result. From the moment the flowering begins, it will be better to switch to one of the mineral fertilizers containing small amounts of nitrogen, but it demonstrates a high concentration of potassium and phosphorus, which the plant needs so much during this period. When drawing up a feeding plan and choosing fertilizers, you need to remember that if the soil for the pot with exacum is compost soil or humus was initially added to it, then it is better to refrain from adding additional nutrients. Otherwise, the plant will intensively grow, but the flowers will never appear.
- Transfer. As a rule, exacum is used as an annual plant. Accordingly, in this case there is no need for a transplant. This option is the simplest and most practical, but if there is a desire to grow perennials, then with the arrival of spring it is necessary to transplant it into soil, which consists of 3 parts of leafy soil and sand with sod soil is taken in 1 part. The acidity of such a composition should not fall below 5; a substrate with weak oxidation (5-6 pH) or completely neutral (6-7 pH) is quite suitable. If you don't feel like messing around with soil mixing on your own, you can purchase a ready-made soil mixture for home ornamental plants at any specialized store. Exakum is planted in small pots, creating a drainage layer in the bottom area.
- Flowering period. If the simple recommendations for caring for the plant have been followed, then Exakum will thank you with abundant flowering, which begins in May and lasts until September inclusive. That is, for about 4 months, the flowerpot will be decorated with a large number of neat flowers 1, 3–1, 8 cm in diameter. But if desired, the flowering period can be extended by another 1–1.5 months. To do this, you should carefully and regularly inspect the shoots, timely removing wilted flowers. In addition, do not forget that exacum is demanding on lighting and feeding, which have a direct impact on the intensity and duration of flowering.
Self-propagating exakum
You can get a new exakum in two ways - through growing seeds or by cuttings. In the first case, the seeds are simply left on the surface of the earth, covering them with plastic wrap. This will create a greenhouse effect with increased heat conservation and humidity. The first shoots can be observed after 11-13 days, and the plant will enter the flowering phase in about 6 months.
For propagation by cuttings, they are taken from an adult exakum, cutting off the top of the shoots with 5 knots. For rooting, take a small container of water or soil, which consists of sphagnum and peat. The rooting process takes about 2 weeks, after which the sprouts can be planted in a pot, where they will develop on a permanent basis.
Diseases and pests of exacum
The main enemy is the spider mite, but sometimes aphids, scale insects and mealybugs cause no less problems.
Preventive measures for pest control. The best way to prevent damage to exacum is to prevent pests. For this purpose, it is required to pre-treat the soil used for the pots. Before disembarking, it should be warmed up in a microwave or oven. The same procedure needs to be done for sand, pebbles, and more. If moss is used for growing seeds, then it is poured with boiling water before use and left until the water cools down. If an adult flower in a pot was bought or donated, then there is no need to rush to put it on the chosen place right away. To begin with, it should be taken to the bath and washed thoroughly, or even better - immediately treated with a solution of acaricide. If prevention did not help, then it is recommended to consider how to eliminate the pests.
- Spider mite … It is almost impossible to notice this pest before it starts its activity, since individual individuals are 0.5 mm in length. But, having settled on a plant, mites multiply and begin to weave a web, which becomes the first sign of problems. If you do not take any measures at this moment, then the pest will actively multiply and suck the juices from the exacum, which, in the end, will lead to the death of the plant. To prevent this from happening, you need to eliminate pests as soon as possible. Begin to combat washing the plants with soapy water. To prepare it, finely rub laundry soap and soak it in warm water, after which they wipe the stems and each leaf, and at the same time the entire surrounding area, since the ticks do not sit still. Such a measure will not destroy them, but the number will be significantly reduced. This is due to the fact that the insect does not tolerate high humidity, therefore, providing comfortable conditions for exakum itself is a means of prevention. Also used are chemicals from the class of acaricides - Aktofit, Fitoverm or Vermitic. Best of all is Apollo, who fights not only with adults, but also destroys eggs laid by ticks. Some sellers may advise Actellik, but it is extremely dangerous to use this drug in residential premises, since its high toxicity poses a threat to humans.
- Aphids easy to see on plants with the naked eye. The insect grows up to 2 mm, has a light green tint and slowly crawls along the stems, leaves and flowers of the exacum. The harm caused by aphids is not limited to the suction of vital juices from the plant, insects also carry dangerous viral diseases, and a fungal infection (soot dew) settles on the sugary traces of life. To combat aphids, insecticides are used. For example, you can use the common Karbofos, Bankol or Akarin.
- Shield easily found on plants, as rounded brownish swellings on leaves and shoots. Both adults and larvae are extremely dangerous for exacum, as they deprive it of vitality and spoil its beautiful decorative appearance. Insecticides (Aktara, Mospilan, etc.) can be used to control larvae and some false types of scale insects, but the usual type of pest does not lend itself to the effects of chemicals, and it will have to be manually removed mechanically.
- The main disease of exacum has become gray rot … Usually it is the result of improper care, which allows the botrytis fungus to settle. Brown spots become a manifestation of the disease, which soon become covered with spores, acquiring a dirty gray tint. To get rid of the fungus, the plant is sprayed with fungicides - Bayleton, Euparen, Fundazol, etc.
Learn more about Exacum in this video:
