Bougainvilleas are sarmentose climbing shrubs, with fickle, often thorny, stems and semi-evergreen, oval, bright green, light, sometimes heart-shaped leaves; the flowers of the bougainvilleas are tiny, tubular, white or cream, but they are subtended by large colored bracts, typically fuchsia pink, but there are many varieties, with white, yellow, red, orange, lilac bracts. The plants were introduced to cultivation in Europe in the 1700s, from Brazil, where they develop naturally, as well as in Peru and Argentina; in nature there are about fifteen species of bougainvillea, but very few were imported into Europe, and in particular Buganvillea spectabilis and bougainvillea glabra. Over the decades, the bougainvillea species, together with others imported by the first botanists from South America, were hybridized several times, and therefore today in the living we find many varieties of bougainvillea whose progenitors are unknown, therefore it becomes difficult to give these plants a correct botanical name. For this reason, there are varieties that are more resistant to cold, others that cannot withstand drought, and also varieties of bougainvillea with very compact shrub development, suitable almost to be grown in the apartment. Generally speaking, they are vigorous and fairly fast-growing plants, which tend to produce a cascade of branches and leaves, which in summer are covered with numerous inflorescences, grouped in groups of three, very showy. They have adapted so well to the Mediterranean climate, that in fact they are now considered typical plants of Mediterranean vegetation, although in general it is difficult to see them develop in the wild, while it is more likely to see them in gardens and parks, especially in coastal areas.
Exposure and terrain
Bougainvilleas are plants that love the sun, only cultivation in full sun guarantees a good flowering, while if planted in the shade they will give rise to a shrub rich in foliage, but completely devoid of inflorescences. They slightly fear the winter cold, and for this reason they are often grown in places sheltered from the wind, leaning against houses, on terraces and balconies, so that they can be protected in case of frost. In any case, they do not like frosts, especially if they are prolonged and intense; slight frosts can sometimes simply cause burning of the outermost branches, leaving the plant undisturbed, and their effects are eliminated in the spring, with a light pruning. In areas with a decidedly cold winter climate, the bougainvillea must be kept in a sheltered place, possibly in a pot, so that they can be completely covered with non-woven fabric in case of intense cold. To prevent the plant from spoiling, in these areas we recommend pruning the shrubs at about 25-36 cm from the ground, so that it is easier to repair all parts of the plant, and also to stimulate a rapid vegetative restart upon arrival of spring.
They prefer very well drained soils, the water stagnation can occasionally cause the loss of the leaves, but if persistent it can also lead to serious damages to the roots, and consequently also to the ramifications.
Even extreme drought can cause loss of foliage, especially if it is prolonged; in fact these plants bear drought well, but if it lasts for weeks the plant defends itself by dropping the entire foliage. This event often occurs in plants grown in sheltered places, where they cannot receive the weather water, for several months.
Watering is provided only when the soil is decidedly dry, from March to October, avoiding excesses, and also avoiding leaving the soil saturated with water for long periods of time; in the cold months it is watered only sporadically, avoiding to water the plants that are exposed to rain water, but remembering however to supply small quantities of water to the plants sheltered from the terraces, or covered by plastic film or by non-woven fabric. During the vegetative period, from April to September, fertilizer for flowering plants is also supplied, dissolved in the irrigating water, every 12-15 days.