Geranium is part of the Geraniaceae family and of the Pelargonium genus, which has several species that differ mainly due to the morphology of the leaf, the flower and the colors of these two elements.
Its origins take us back to southern Africa characterized by a tropical, rainy climate, whose temperatures are mitigated by the various plateaus that extend into those places.
The geranium generally has a suffruticoso or shrubby habitus and is perennial. The stem is fleshy and in some cases woody with an upright habit. The leaves are alternate and endowed with petiole, the forms vary considerably from species to species but generally they oscillate between those pointed and lobed. The ribs are very evident, the margin can be dentate and some species have tomentum-covered leaves, ie a thick layer of thin hairs and are strongly odorous.
The flower is the element that drives many people to use these plants to embellish their balconies. It has an incredible diversity of shapes and colors starting from the pink ones of the crispum, from the white ones of the domesticum, to the purple-red ones of the angulosum. The characteristic that unites them all is the basic structure: they constitute particular inflorescences and always have five narrow sepals and tomentoses and five petals. The flowering period goes from spring to autumn and this phase is followed by the production of numerous berries of unusual shape characterized by a long beak in an apical position.
As already mentioned, they are grown at home and, with a few simple cultivation geranium techniques, give an excellent result.
Those who do not understand plants and flowers, the word Geranium cannot associate a precise image because so many species are known to the genus Pelargonium, all well known. Just to mention a few: Pelargonium grandiflorum which bears large flowers with colors ranging from white to pink with purple veins; P. peltatum also known as Geranium ivy showing leaves similar to those of ivy, pink, reddish or white flowers and blooms from May to October; P. tomentosum, on the other hand, has a creeping habit, white flowers and leaves which, when rubbed, give off a pleasant scent of fresh mint; the P. zonale, whose leaves have a dark spot in the center, the leaves are roundish, the flowers can have a single color or streaks and bloom to form umbrellas.
But these are just a few examples to show how vast this genus is.
Geraniums cultivation and multiplication
Almost all representatives of Pelargonium can be grown at home trying to respect simple but important precautions. They can tolerate winter temperatures up to 7 degrees without suffering damage, while during the summer they adapt even at rather high temperatures.
They need a lot of light even if it should arrive directly on the plant, obviously not for too long periods. During the cold season, if the temperatures should be particularly rigid, it is advisable to move the plants to places sheltered from frosts and to reduce the water supply to allow them to perform their regular vegetative rest. Instead, it is important to water well during the summer; generally it is necessary to do it every two days but if the temperatures are very high, even daily. The amount of water must not create stagnation in the soil, but must be sufficient to wet it.
The land that we recommend to use is a mixture of peat and clayey soil to facilitate water drainage.
Geranium is multiplied by cuttings; this process must be carried out in March or in summer, creating a cutting of 8-10 cm from the already existing plant. At this point prepare a small pot with peat and sand that must be kept moist and not in direct contact with sunlight.
When the first shoots are noticed, the new seedling can be moved to a more welcoming vessel, but not of a large size, with the characteristics described above.
The Geranium needs the annual pruning that must be done in spring and the branches must be cut to a third of their length. Pruning will make the plant stronger and more resistant.
Cultivation geraniums: Diseases and pests
Every plant always expresses its state of health externally, as soon as it shows particular signs one must immediately put in alarm and try to understand what the problem is. In the specific case of Geranium, we must pay attention to the colors of the plant: if the stem becomes dark at the base it means that too much water has been given to it and that specimen must be eliminated; if the leaves become dark, instead, they suffer from a lack of water; if both the stem and the leaves become yellow it means that it does not have enough light.
One of the most serious problems is due to the attack of parasites such as Aphids, which pierce the plant and favor the entry into it of other harmful organisms; Cochineals, which cover the soft parts of the plant leading to death; gray mold that attacks both young and adult individuals.
Aphids require treatment with specific insecticides, Cochineals can be removed with the help of a cotton pad soaked in water and alcohol while mold needs special fungicides.