ROSE

ROSE

The rose genus belongs to the family of the Rosaceae and includes around 250 species native to Europe and Asia and dozens of thousands of cultivars and varieties that derive from centuries of hybridization and breeding by floriculturists. The rose genus includes species with very diverse shapes ranging from small to big shrubs, and from climbing, to sarmentous, to trailing plants. Roses have been cultivated since very ancient times both for the beauty of their flowers and for their medicinal properties. In the Middle Ages, a variety of red rose was widely grown and became the symbol of the Lancasters, traditionally opposed to the Yorks, represented by the white rose. Up to 30 species in Italy are spontaneous such as: R. canina, R. gallica, R. glauca, R. pendulina, and R. sempervirens. With the introduction in Europe of the remontant Asian roses and of the Chinese Tea roses, hybridists put varieties of roses on the market that were ever more beautiful and able to bloom during the entire season. Today there are up to 20 thousand varieties, with the most diverse shapes and flowering characteristics. For their cultivation, there are a few basic rules common to all roses. As far as exposure is concerned, they prefer full sun and tolerate part-shade; as far as soil is concerned—both in vases and in the ground—rose plants prefer a substratum rich in organic substances that provides good drainage and avoids waterlogging, or even calcareous soils. For potting, a good compost requires a mixture of 60% organic compost and 40% inert material, with the addition of a slow-release fertilizer. As far as water is concerned, roses must be watered thoroughly and on a regular basis to avoid the withering of the leaves. Every fortnight, it is advisable to add a soluble ternary fertilizer to the irrigation water. The varieties of bush-like rose plants with big flowers need to be green pruned and dry pruned. Green pruning consists of removing withered flowers by cutting the stem above the first leaf under the flower. During summer, it is advisable to remove the “suckers” or branches with few flowers that grow at the base of the plant and that deprive it of energy needed for flowering. This practice avoids the production of seeds, keeps the plant in shape, and guarantees abundant flowering. Winter pruning, instead, is done to reduce the size of the rosebush or of the shrub and to guarantee a compact shape as well as to stimulate blooming the following spring. Pruning must be done by shortening the longer branches, cutting those which are weaker or damaged, and removing any suckers that may have developed at the base of the plant. Rose plants generally fear fungi and insects; it is, therefore, advisable to prevent disease by spraying them with copper or sulfur to keep downy mildew, rust, and oidium in check. Against animal parasites, particularly aphids and spider mites, one can apply specific aphicides and acaricides when they appear.

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