The Crossandra is a perennial plant, evergreen, suffruticosa, native to India, the Middle East and Africa; the various species grow in tropical, warm and humid climates. In the nursery we find only a couple of species: the infundibuliformis and lanilotica. They are quite particular plants, often cultivated as houseplants, or used in the flowerbeds of the garden, as if they were annuals. They have large lance-shaped leaves, bright green, shiny, with well-defined veins and with a slightly wavy edge; starting from spring, until autumn, they produce long panicles, which carry numerous flowers, generally in shades of orange; there are many varieties, even with white or yellow flowers. In nature these plants tend to bloom throughout the year, and they do so even if they are grown in pots, but only if the climate is the ideal one for their development. Over the years a plant of crossandra it tends to lignify at the base, and can form a shrub up to 70-80 cm high, although cultivation in small pots tends to keep plants of dimensions that do not exceed 50cm in height, and 40 in width.
In the apartment the crossandra it is cultivated in pots, possibly the cotto ones, of not excessively large dimensions; if desired they can be placed in the garden, using a very well drained, fresh and rich in organic matter. Plants grown in the garden, exposed to the elements and the natural climate, tend to dry up and die when autumn arrives; the Crossandre are in fact plants that love the heat, and therefore can be moved outdoors only when the minimum temperatures are above 15 ° C, and they dry up quickly with temperatures below 12 ° C. While loving the heat, they do not like direct sunlight, which can lead to large burns on large leaves; they are therefore cultivated in very bright places, but not exposed to sunlight, and therefore shaded. They can withstand short periods of direct sunlight, but only in the case of cool weather and only in the hours when the sun is not yet high in the sky, so in the early morning hours. They are plants of tropical origin, and therefore besides a warm climate, characterized by a steady air, without exposure to air blows, they also love a high humidity of the air and regular watering. If cultivated in the garden, they are watered very regularly, every time the soil tends to dry, we avoid damaging stagnation; if grown in pots it is advisable to water regularly, and to vaporize the leaves often. To increase the humidity present in the air, the vases are generally placed in large pot holders, filled with gravel or pebbles, where we will always leave at least 3-4 cm of water, which will tend to evaporate, increasing the water present in the air. Certainly, the plants grown in the apartment suffer from the dryness of the air, where the air is very dry, especially in winter.
Land, repotting, the Crossandra in the apartment
The crossandre grown in pots should be repotted at least every two years, as the roots tend to develop and fill the pot throughout its capacity; therefore we choose a slightly larger container and move the plant, trying to avoid ruining the earthen bread around the roots; the plant is repotted at the beginning of autumn, when it has stopped flowering. Before repotting, and in any case every autumn, it is advisable to prune the plant, shortening the branches that carried the flowers, up to about 20-30 cm from the ground: in this way we will obtain over time a compact and dense shrub.
For all the vegetative period let's remember to fertilize the plants, using a fertilizer for flowering plants, to be dissolved in the water of the watering, every 12-15 days; when, at the end of winter, we move our outdoor plant, remember to clean its leaves, using a slightly damp microfibre cloth; in the same period we also remove dry or damaged leaves, which can be a vehicle for the development of mold or rot.
Propagate Crossandra, cultivation in the garden
Crossandra is a plant of tropical origin, which cannot survive the autumn and winter temperatures present in Italy; so if we decide to prepare a crossandre flowerbed, we will also have to be aware of the fact that, when the cold comes, our plants will deteriorate quickly and visibly. To keep our plants from year to year we have two options: either in autumn we prepare cuttings, to be cultivated in pots in the apartment for the whole winter and to be planted at the arrival of the next hot season; or we can preserve the woody pods that contain the seeds, with which we will prepare small plants in February-March, in sheltered seedbeds. Cuttings and plants obtained from seed are quickly prepared with Crossandre, and have the advantage of starting to flower already when they are quite small, even only 10-15 cm in height. We will only have to be careful: the seeds are contained in a semi-woody sheath; at the arrival of the cool and wet autumnal period, these sheaths tend to explode rapidly, as for example the wisteria pods, spreading their contents all around; therefore it is important to collect the seeds already in late summer, when the containers are already dry, and keep them in a dry and dark place until the following year.
The cuttings are prepared by taking, in summer or early autumn, the tips of the branches that have not brought flowers; the leaves in the lower part are raised, the bottom of the cuttings is immersed in the rooting hormone and it is placed in a vase, with top quality soil, already slightly damp. The pots with the cuttings are kept in a warm place, with a minimum of 15-18 ° C, and bright, and are watered regularly, every time the soil tends to dry. The seedbed is prepared instead in February or March, and is kept in a warm and sheltered, bright place, but without direct sunlight. The seeds are spread on the surface, and watered regularly, using a vaporizer, so as not to disturb the seeds. If our laziness is so great, we can also simply, every year, buy new plants in the nursery, as if they were common annual plants. Or we can keep the Crossandras in pots, and put them in the flowerbeds with the whole vase, which in the autumn we are going to dig up, in order to move the plant into the apartment.