HOW TO GROW AND CARE FOR OUR PLANTS
There Crossandra is a nice plant native to the semitropical forests of America, Asia and Africa.
Species: see the paragraph on "Main species"
The genre Crossandra belongs to family of Acanthaceae and includes plants native to the semitropical forests of America, Asia and Africa.
The name Crossandra derives from the Greek krossos «fringe "eandros "Male" referring to the fact that the male reproductive organs, the anthers, are frayed.
They are sufruticose plants that is to say they are perennials that lignify only at the base and that every year emit herbaceous branches that remain only for a vegetative cycle and then dry up.
They are not plants that reach considerable dimensions in fact they do not exceed one meter in height.
The leaves they are lanceolate, large, shiny and of a beautiful very intense green color. They have rounded edges and the ribs are very evident.
THE flowers of the Crossandra are orange, yellow or salmon in color, gathered in spikes and begin to appear in spring and remain throughout the summer until autumn.
THE fruits they are pods that contain 1-4 seeds inside.
There are about fifty species ofCrossandra among which we remember:
ThereCrossandra infundibuliformis it is also called CROSSANDRA UNDULIFOLIA.
It is a plant native to India and Malaysia and is the most cultivated species.
They are not plants that reach large dimensions in fact they do not exceed 60cm in height with very large leaves, of a beautiful intense green and glossy color.
Of the Crossandra infundibuliformis there are several varieties that differ from each other for the different shades of color of the flowers.
There Crossandra nilotica it is native to Tanzania and is characterized by very intense yellow-orange flowers.
It is a plant that can reach even one meter in height.
The Crossandra they are not very easy plants to grow. In fact, their only flaw (if you can call it that) is that they are delicate and require constant heat and humidity.
The optimal cultivation temperatures are in the summer around 24 ° C or higher but in this case it is necessary to give the plant an excellent environmental humidity (remember that they are plants of tropical origin). Conversely, the minimum winter temperatures must never drop below 15 ° C.
The light must be good without exposing the plant to direct sun which damages the leaves and blocks flowering.
Beware of cold drafts that the Crossandra does not like in any way.
From spring and throughout the summer there Crossandra it should be watered so that the soil always remains slightly humid (not wet) and without leaving stagnant water in the saucer.During the winter it is watered more moderately with warm water always keeping the soil slightly moist.
Use non-calcareous water.
For the Crossandra it is therefore necessary to pay close attention to the amount of water that is administered: remember to always keep the soil just moist, neither dry, nor too wet.
They love humid environments so it is advisable to spray the leaves regularly (early in the morning so that the leaves are dry in the evening) and place the plant on a saucer full of pebbles and then fill it with water, making sure, however, that the bottom of the pot is not immersed in water as in this way the soil would become saturated with water, causing the roots to rot. This system allows, when heated, to evaporate the water from the saucer which consequently moistens the surrounding air. Remember to fill the saucer whenever the water has evaporated.
TYPE OF SOIL - REPOT
There Crossandra it is repotted when the roots have occupied all the space at their disposal using a good fertile soil mixed with a little sand to favor the drainage of the irrigation water as water stagnations are not tolerated.
They like soils with neutral or slightly acidic pH.
Personally, I always recommend using clay pots even though many opt for plastic pots (less expensive and more drainage holes). I believe that the terracotta ones allow the earth to breathe and if the drainage hole has been arranged in such a way as to guarantee a good drainage of the water, well, I would say that it is perfect.
From spring and throughout the summer fertilize the Crossandra every 2 weeks with a liquid fertilizer to be diluted in the irrigation water by slightly decreasing the doses compared to what is written on the package.
Use a fertilizer that in addition to nitrogen (N), phosphorus (P), potassium (K) also contains the so-called microelements, i.e. those compounds that the plant needs in minimal quantities (but still needs them) such as magnesium (Mg), iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), ilboro (B), molybdenum (Mo), all important for a correct and balanced growth of the plant.
There Crossandra it blooms from spring and all summer until autumn producing delicious orange, yellow or salmon colored flowers depending on the species and variety often gathered in spikes.
The blooms are favored by high temperatures and high ambient humidity.
There Crossandra, at the end of the flowering period it should be pruned by shortening the flowering branches up to 2/3 of their length.
The leaves as they dry must be removed to avoid the onset of rot and mold.
Sterilize, possibly over a flame, the shears you use to cut, especially when passing from one plant to another. If, on the other hand, you do it with your hands, well, take care that they are well cleaned.
There Crossandra it multiplies by cutting and by seed.
In choosing the technique to be adopted, it must be borne in mind that multiplication by seed has the disadvantage that, taking over genetic variability, it is not certain that plants will be identical to the mother plants, in which case if you want to obtain a well-defined or not if you are sure of the quality of the seed you are using, it is good to do the multiplication by cutting.
MULTIPLICATION FOR TALEA
The cuttings can be taken from the stems in early spring and should be about 7-10 cm long.
The cuttings should be cut immediately under the node so that some leaves remain and eliminating the lower ones. Also choose them from robust and healthy plants.
It is recommended to cut obliquely as this allows for a greater surface for rooting and avoids the accumulation of water on this surface.
Use a razor blade or sharp knife to avoid fraying of the fabrics. Make sure that the tool you use for cutting is clean and disinfected (preferably with the flame) to avoid infecting fabrics and disinfect it at each cut.
Immerse the cut part in a rhizogenic powder mixed with a good broad spectrum fungicide (available from a good nurseryman) to promote rooting and prevent any fungal attacks.
Subsequently, the cuttings are arranged in a compound formed in equal parts of turpentine and coarse sand. Make a hole with a pencil and place it to a depth of 1.5-2 cm. Then take care to gently compact the soil.
The box or pot is covered with a transparent plastic sheet (or a bag with a hood) and is placed in the shade and at a temperature around 21 ° C taking care to keep the soil always slightly moist (always water without wetting the rooting plants with water at room temperature). Every day the plastic is removed to control the humidity of the soil and to eliminate condensation from the plastic.
Once the first shoots start to appear, it means that the cutting has taken root. At that point he removes the plastic and places the pot in a brighter area, at the same temperature and expects the tales to strengthen.
Once they have grown sufficiently large and have produced vigorous new shoots, they transplant into the vasoo in the final soil.
Do not disturb the cuttings until the new shoots have been placed.
As for SEED MULTIPLICATION it is carried out in March by distributing the seeds as evenly as possible, give them small sizes, in parallel rows on a seed soil.Since the seeds are small, to bury them slightly, push them under the soil using a piece of wood dish.
It would be a good idea, to prevent any attacks of fungi, to administer with the irrigation water also a broad spectrum fungicide, in the doses indicated in the package.
The tray containing the seeds should be kept in the shade, at a temperature of around 27 ° C and constantly humid (use a sprayer to completely moisten the soil) until the moment of germination.
The tray should be covered with a transparent plastic sheet that will guarantee a good temperature and avoid too rapid drying of the soil.
Once the seeds have germinated, the plastic sheet is removed, and as the seedlings grow, the amount of light is increased (never direct sun) and ensure good ventilation. those less vigorous than others. Identify and eliminate them in this way you will guarantee more space for the most robust plants.
When they are large enough to be manipulated (5-6 cm), you will transplant them, in any case being very careful not to spoil any part of the plant (it would be preferable to use a fork for these operations that you will insert under the ground to take the whole plant and place it in the new pot) in a soil as indicated for adult plants and treated as such.
PARASITES AND DISEASES
The leaves turn black
This symptomatology is due to too low temperatures, especially in winter.
Remedies: Move the plant to a warmer location and remove damaged leaves.
Crossandra does not bloom
This symptomatology is due to too little light.
Remedies: place the plant in a more suitable position.
Leaves completely withered starting from the basal ones
If the plant presents this symptomatology we are most likely in the presence of a fungal attack that can be caused by various fungi such as Rhizoctonia spp., Phytophtora spp. or Pytiumspp., all pathogens that cause root and root rot.
Remedies: use a specific fungicide even if, when the rot occurs on the leaves, it is difficult to recover the plant. It is necessary to prevent this pathology by avoiding excessive watering and excessive humidity, especially when the plant is in bloom.
Leaves that begin to turn yellow, appear mottled with yellow and brown
If the leaves begin to turn yellow and after these manifestations crumple, they take on an almost powdery appearance and fall off. Observing carefully you can also notice some thin cobwebs especially on the underside of the leaves. With this symptomatology we are very likely in the presence of an attack of red spider, a very annoying and harmful mite.
Remedies: increase the frequency of nebulizations to the foliage (the lack of humidity favors their proliferation) and possibly, only in the case of particularly serious infestations, use a specific insecticide. If the plant is not particularly large, you can also try cleaning the leaves to mechanically eliminate the parasite using a wet and soapy cotton ball. After that the plant must be rinsed very well to remove all the soap.
Presence of small whitish animals on the plant
If you notice small white-yellowish-greenish mobile insects you are almost certainly in the presence of aphids or as they are commonly called lice.Observe them with a magnifying glass and compare them with the photo on the side, they are unmistakable, you can't go wrong.
Remedies: treat the plant with specific pesticides readily available from a good nurseryman.