Crossandra

Family. Acanthaceae.

Origin. Subtropics of India.

Description. The genus "Crossandra" consists of 50 evergreen perennial shrubs and subshrubs with erect stems.

The leaves are dark green, shiny, lanceolate, up to 12 cm long, arranged oppositely. Leaf blades with wavy edges.

The flowers appear at the tops of the shoots in spike-shaped inflorescences up to 15 cm long, in most cases orange or coral, but can be pink, yellow or red, with 3-5 asymmetrical petals and a long flower tube, contrasting well with the dark foliage.

Height. It can grow up to 1 m in several years, but usually no higher than 60 cm. The plant develops quickly and needs regular pruning. 

Care at home

Reproduction 

Crosandra is quite easily propagated by semi-woody stem cuttings 8-10 cm long, taken during pruning in spring and summer. The lower leaves are removed from the cuttings, and the bases are treated with growth hormones.

For rooting, take a transparent plastic container with a lid, make drainage holes in the bottom of which and pour a drainage layer in the form of fine expanded clay. Fill the container with nutritious soil based on peat with the addition of a generous amount of river sand.

The surface of the substrate is thoroughly moistened with a spray bottle with water at room temperature. The bases of the cuttings are immersed in the ground by 1-2 cm at a slight angle.

The seedlings are covered with glass to maintain humidity and kept warm - at a temperature of about 24 - 26 ° C. Using bottom heating increases the chances of successful rooting of the cuttings.

Place the tray in a well-lit place, but remember that the leaves should not be exposed to direct sunlight. The bushes are aired daily, removing condensation that appears on the cover. The airing time is gradually increased. Rooting occurs within 3 - 6 weeks.

The fact that the first roots have appeared under the surface of the soil can be judged by the formation of young leaves. A month after the start of new growth, the cutting can be transplanted into a separate small pot and cared for like an adult bush. When 3-4 true leaf blades appear on each young shoot, pinch off their tops.

The cuttings successfully root in water. With this method, fill a glass with water at room temperature and add a tablet of activated carbon to it.

Only the lower part of the shoot, about 1 cm, should be immersed in water. Every 5-6 days, change the water in the glass for new. Within 3-4 weeks, the first roots will appear at the base of the cutting. As soon as the roots reach 1 cm in length, the seedlings are planted in the substrate.

For 1 - 2 weeks, such plants will not show any signs of growth - at this time their roots adapt to their new conditions.

Rooting of cuttings in carefully soaked peat tablets goes well. The advantage of this method is that the flower is initially in a loose and nutritious medium, and when planting in a pot, it is carefully rolled over - together with the tablet.

To make the plantings appear denser, 3-4 cuttings are planted in each pot. The specimens obtained by cuttings bloom a few months after successful rooting.

Crossandra is rarely propagated by seeds - plants obtained from seeds often do not inherit the declared varietal characteristics of the parent bushes and bloom less abundantly and inconspicuously.

For seed propagation, you can use self-collected planting material, but it is worth remembering that the seeds must fully ripen directly on the plant. The germination of fresh, self-collected seeds is high, it decreases 2-3 years after collection.

If purchased planting material is used for propagation, it is first immersed in warm water with the addition of phytohormones.

Sowing is carried out in the spring, in a container with a lid, filled with a moist and nutritious substrate. The seeds are laid out on the surface of the soil and lightly sprinkled with a layer of soil about 5 mm thick. The crops are moistened from above with a spray bottle and covered with a lid to maintain high air humidity and create a greenhouse effect.

The container is placed in a well-lit place without direct sun with a temperature of 22 - 24 degrees Celsius. Every day the lid of the container is lifted, water condensation is removed and the crops are ventilated. After 2 - 3 weeks, you can notice the appearance of the first shoots. Higher air temperatures will promote even faster seed germination. 

The ventilation time is gradually increased, hardening the seedlings. With the appearance of 2-3 real leaves, the flowers are picked into separate pots with a diameter of about 7 cm.

The picking is carried out as carefully as possible, trying not to damage the root system of the bushes. 10 days after picking, nitrogen fertilizers are applied for the first time in a very low concentration.

After another 1-1.5 months, a second picking is carried out into larger pots with a diameter of about 10 cm and young shoots are pinched to form lateral branches.

Growing at home, pruning

It is unlikely that crossandra can be recommended for cultivation by novice gardeners, since the flower has a complex character and requires careful care.

The first bushes that people tried to keep at home constantly died from insufficient air humidity, and only time and long-term efforts of breeders adapted this plant to indoor conditions.

Pluck off wilting flower stalks to extend the flowering period - this stimulates the bushes to form new buds. Too long or weak stems also need to be cut off. The best time for formative pruning is considered to be autumn - when flowering has ended.

Pruning can also be done in the spring, but it is worth choosing a time when the buds have just swollen and the plants do not yet show obvious signs of new growth.
Pruning is carried out with a sharp, sterilized tool - a knife or pruning shears. Do not remove more than 1/3 of the growth at a time. The cuttings obtained during pruning are used for further propagation.

During sanitary pruning, which can be done at any time of the year, weak, diseased and dried, dead stems are removed as needed. Such pruning will help maintain an attractive appearance. The tops of young shoots are regularly pinched so that the plant branches better and looks thicker.

In late spring and summer, if possible, put the pot outside. The place should be protected from wind and rain, for example, on a terrace or balcony. Before leaving the flower for a day, gradually accustom it to new conditions, leaving it outside during the day and gradually increasing the hardening time.

As soon as the ambient temperature at night drops to 13 ° C, crossandra is brought back into the house. With short daylight hours and lower temperatures, the plant slows down or even completely stops its development - this is normal.

From time to time, smooth leaf blades should be wiped with a damp sponge, removing dust from them. Do not place the pot in close proximity to heating systems - dry and hot air will quickly spoil the appearance of the bush.

If in the winter months the flower pot is on a too cold windowsill, it is better to put a folded newspaper or a sheet of insulation under it.

Diseases and pests 

• Leaves fall off with a sharp change in air temperature, leaf edges dry out with insufficient air humidity.
• When watering with cold water, spots appear on the leaves.
• Leaf blades become soft, and stems become thinner when water stagnates - rot appears. Brown spots on the leaves become a sign of hypothermia of the root system - water only with water at room temperature.
• Lower leaves fall off when exposed to cold drafts. Flowering will be less abundant with insufficient light or when grown in a large container.
• Crossandra sometimes does not bloom due to the lack of a dormant period.
• Excessive nitrogen in the soil will lead to the bush forming green mass instead of buds.
• Leaf blades lose turgor due to insufficient watering.
• Too low temperatures or exposure to cold drafts negatively affect the appearance - leaf blades turn black and fall off.
• Under the influence of direct sunlight, the shade of the leaves fades, becomes paler and lighter.
• Fungal diseases appear when the plant is kept too cool and humid in rooms with insufficient air circulation.
• The leaf blades become light or even yellow, but the veins remain green with the onset of chlorosis. This disease occurs when watering with unsettled tap water. You can cure a flower by replanting it in an acidic substrate and feeding it with iron chelate, applying it directly to the leaves.
• When planted in a large pot, flowering is delayed until the entire earthen ball has been absorbed by the root system.

Pests on bushes may include spider mites, aphids, mealybugs, and whiteflies. 

When it blooms 

Buds appear abundantly in spring and throughout the summer. Plants bloom for the first time at the age of 6 months. Each flower remains open and attractive for 2-3 days, blooming from the base of the inflorescences to the tops.

With proper pruning, you can expect a second wave of flowering, but it will be less abundant. Fading inflorescences should be cut off in time - then the bush will have time to form new buds.

How to transplant

Crossandras are often grown as annuals and thrown away after flowering - they often do not need replanting. Representatives of the genus do not like frequent replanting - they experience stress and are ill for a long time after the procedure.

After replanting, the bushes can shed some leaves, leaf blades curl, and the formation of buds is delayed.

If you keep the bush as a perennial, replant it in the spring, into fresh soil, increasing the volume of the pot if necessary. Each time, select a pot that is 2 - 3 cm larger in diameter than the previous one.

Containers should be deep enough. The need to replant young seedlings will be indicated by the tips of the roots protruding in the drainage holes of the pot. Planting immediately in a large container will lead to root rot, since a large volume of soil will retain water after watering.

Young specimens need to be replanted annually, as their root system grows and requires more and more space. Adults are replanted as needed to replace the substrate with a fresh mixture - approximately every 2 - 3 years.

For large plants, it is enough to replace the top part of the soil with fresh soil. Crossandras bloom more abundantly if you choose a slightly tight pot for them.

Do not replant during flowering.

Before moving the flower, make sure that there are drainage holes in the bottom of the pot, and put a drainage layer several centimeters high on the bottom. The drainage layer can be made up of such components as expanded clay, river pebbles, pieces of foam. Place a small amount of soil on the drainage layer.

Before replanting, water the soil in the old pot generously with warm water - this will make it easier to separate the root ball from the walls.

If there are no signs of disease on the bush, then carry out careful transshipment. When replanting, keep the root ball intact and simply place the flower together with the old soil in the center of the new pot.

Sprinkle the root system with fresh soil, filling all the voids between the walls and the plant. When replanting, make sure that the crossandra remains at the same depth as in the previous container.

The surface of the substrate after replanting should be 1 - 2 cm below the level of the walls of the pot. If necessary, after replanting, lightly compact the soil with your fingers and water the flower. If after watering the surface of the substrate sags and holes appear, they are covered with fresh soil.

After planting, spray the leaves with phytohormones and place in a place shaded from direct sunlight for 7 - 10 days.

Transplanted specimens should not be fed for 2-3 weeks - the elements that are already in the new soil will be enough for them. If the bush shows signs of root rot, it is worth replanting and completely replacing the soil.

The flower is cleaned of the old substrate and, if necessary, old and rotten roots are cut to healthy tissue. After this treatment, the root system is sprinkled with crushed charcoal or ash.

Such plants are planted only in a new substrate, since pathogens can remain in the old one.

Soil 

Suitable soil consists of peat, leaf and turf humus, with the addition of river sand. Crossandra requires good drainage - such as perlite or vermiculite added to the soil to support the flower. Coconut fiber also loosens the soil well.

You can increase the moisture capacity of the substrate using sphagnum moss. The substrate should have a slightly acidic or neutral pH and have excellent permeability of not only water, but also air to the root system.

For additional nutrition and maintaining the required pH level, a small amount of finely chopped pine needles is mixed into the soil. From ready-made soils, you can pick up soil for azaleas and rhododendrons at a flower shop. 

Watering

Crossandra does not tolerate drought and waterlogging, carefully monitor the frequency of watering. Water abundantly until the soil lump is completely saturated with warm water. Tap water should be pre-settled for 24 hours so that the salts contained in it precipitate and the chlorine evaporates.

You can water with melted or rainwater, but it should be collected away from industrial enterprises and roads. Plants respond well to watering with filtered and bottled drinking water.

During the period of active growth and budding - in spring and summer - the top layer of soil about 3 cm thick should dry out before each subsequent watering.

In winter, the soil should be almost dry - reduce the frequency of watering so as to protect the soil from drying out completely. Do not use too cold water for watering.

Excess moisture that appears in the tray after watering drains after a few minutes. In spring and summer, you can use bottom watering by submerging the flower pot in a larger container filled with warm water for a few minutes and allowing excess moisture to drain through the drainage holes in the pot.

Feeding

Potted plants have a limited feeding area and require regular fertilization. When crossandra begins to grow, feed it with liquid fertilizers with a high potassium content twice a month. In winter, fertilization can be done monthly. If the flower is in a cool room, then fertilization should be completely stopped until spring.

Liquid mineral fertilizers for flowering plants are used for fertilization. It is better to dilute the solution to half the recommended dose on the package and apply more often than to fertilize rarely and with too concentrated solutions.

Add nutrient liquid only after abundant watering. Do not apply fertilizers to dry soil - the root system can get chemical burns.

Lighting

Crossandra thrives in bright, reflected sunlight. In the morning and evening, the leaves may receive some direct sunlight. During the day, in spring and summer, use shading in the form of a light curtain.

When the sun rarely appears from behind the clouds, in autumn and winter, you need to provide maximum light. The bush will feel great and bloom abundantly on south-eastern or south-western windowsills.

When placed on a southern window, you can place the pot in the back of the room or close it from direct sunlight with a curtain.

It is undesirable to place the pot on the north side - the bush will bloom poorly, become elongated and weak, and may even die.

If there is insufficient natural light, you can turn on artificial lighting in the morning and evening hours. Fluorescent daylight lamps or special phytolamps can be used as a light source.

With good lighting, the leaves often acquire a reddish tint. Every week, the pot is turned a quarter of a turn around its own axis so that the flower does not reach for the light source.

Temperature 

The plant is kept at a moderately warm temperature all year round - about 18 - 24 °C. Representatives of this genus do not like extreme heat and sudden temperature changes in general. If hot summer days come (the air temperature rises above 23 °C), the crossandra is transferred to the coolest possible room, the frequency of watering and the importance of ventilation are increased.

In the fall, the temperature can be gradually reduced, and in the winter months it is advisable to provide a cool dormant period, which should take place in a room with a temperature of 16 - 18 °C.

The flower should not be exposed to temperatures below 12 °C. It can be kept all year round at normal room temperature, but in this case it is worth providing artificial additional lighting in winter.

When kept warm, the bush continues to develop, but in conditions of insufficient light, new shoots will become weak and elongated.

 

Spraying

Crossandras love high air humidity - use a room humidifier or a tray of water. The flower will feel good only at a relative humidity of at least 50 - 60 percent.

The buds do not like drops of water and quickly lose their attractiveness; spray carefully, getting only on the leaves. Spraying is carried out mainly in the first half of the day - the water that gets on the leaves should have time to dry before darkness.

For spraying, use only warm and well-settled or purified water, since tap water can leave unsightly whitish spots on the dark shiny leaf blades.

You can put the pot in a tray filled with wet pebbles, but make sure that the surface of the water in the tray does not touch the bottom of the pot. Place any open container with water next to the flowerpot or simply surround the crossandra with other flowers - the water evaporating from their leaf blades will naturally increase the air humidity.

You can put a layer of wet sphagnum moss next to the pot. Keep the crossandra away from window and door openings where drafts are possible.

In summer, once a month, if the bush does not bloom, you can give it a warm shower. Cover the soil in the pot with plastic wrap or a bag, protecting it from erosion, and place the flower pot in the bathtub.

Turn on warm water at a temperature of 35 - 40 degrees Celsius and spray the leaves for several minutes. Such water procedures will have a positive effect on the appearance and prevent the invasion of harmful insects, such as spider mites.

Leave the flower in the bathroom for half an hour in a warm and humid atmosphere. Crossandra does not like polluted air, so you should not keep it in the kitchen or on the balcony facing a busy avenue.

Purpose

An ornamental flowering species with a very long flowering period.

Note

Crossandras can live indoors for several years, but with age they often lose their attractiveness. Replace such specimens with new seedlings obtained from seeds or cuttings. With age, flowering becomes sparse.

Hydroponics

Grows well in hydroponics.

Varieties:

Crossandra infundibuliformis

A green tropical shrub, native to South India and Sri Lanka, reaches a height of 30 - 90 cm, has abundantly branched, erect stems. The leaves are dark green, glossy, lanceolate, reaching a length of 5 - 10 cm. The flowers are collected in small apical inflorescences, have asymmetrical petals of yellow, orange, salmon, coral, red. flowering can occur at any time of the year. 

Crossandra infundibuliformis 'Fortuna'

Perennial evergreens with very abundant and long-lasting flowering. It has glossy, green, lanceolate leaves with branched veins slightly recessed into the leaf blades. It develops very quickly. During the flowering period, short peduncles are released at the tops of the stems, which bear bright, orange flowers. 

Crossandra pungens

Evergreen plants that can safely be classified as both decorative deciduous and flowering. This type of crossandra is often grown as a ground cover plant. The bushes have erect stems with long, lanceolate, dark green leaves. On the surface of the leaf plates, leaf veins are highlighted with a silvery tint. Leaves collected in whorls. During the flowering period, large inflorescences with delicate, cream or yellow flowers appear at the tops of the stems. 

Crossandra nilotica

An evergreen tropical plant 30 - 60 cm high with dark green, spear-shaped leaves. In the warm season, it forms apical inflorescences with brick-red or pink flowers. The leaf blades have branched veins, slightly recessed into the surface. 

There are variegated or variegated Crossandras, in which the main shade of the leaf blades is light green or white, and small green specks are scattered throughout it.