Geraniums are a popular and common potted flower.

Geraniums come from southern Africa and settled in our country over a hundred years ago. They bloom in clusters, full and round, pleasing to the eye, and can adapt to both north and south, found in thousands of households. In hot seasons, place them in a shaded outdoor environment; in cold seasons, enjoy them indoors in bright light. They can bloom on time for "May Day," "National Day," New Year's Day, and Spring Festival, with a very long flowering period.

Geraniums are also known as yangxiuqiu and rulahong, and are evergreen subshrubs of the genus Pelargonium in the Geraniaceae family. Young plants are herbaceous, fleshy and juicy; old plants are semi-woody with hollow pith. The whole plant has a distinctive scent. The simple leaves are alternate, round, kidney-shaped, or fan-shaped, with shallow palmate lobing. Umbels grow at the tips of young branches, with fairly long peduncles bearing fine hairs; the involucre contains several to dozens of small flowers, in white, pink, peach red, flesh red, bright red, light purple, and bicolor, with single- and double-flowered varieties, as well as variegated leaf forms whose leaf surfaces are inset with yellow, white, purplish red, and other markings.

There are many kinds of geraniums. Common ones include zonal geranium (yangxiuqiu, with a ring of purplish brown often appearing around the middle of the leaf), ivy geranium (climbing xiuxiu), regal pelargonium (yanghudie, a hybrid single-season flowering variety), scented geranium (leaves fragrant, stems and leaves containing geraniol and citronellol), fragrant pelargonium (musk geranium, small white flowers, containing aromatic oil, releasing fragrance when the leaves are touched), and cineraria-leaved geranium, whose stems have long hairs, leaves are nearly triangular, deeply bipinnatifid, and bloom in summer.

Most plants in the genus Pelargonium originate from the Cape of Good Hope area of South Africa. They like a mild climate and a fresh environment. In winter they fear severe cold and dry air; in summer they fear intense heat and dampness. The suitable growing temperature is 15°C to 20°C. In winter it should not be lower than 5°C; in summer, above 25°C the plant enters dormancy or semi-dormancy. In hot seasons (above 25°C), keep them in a shaded environment for care; at low temperatures (below 20°C), they need sufficient light. They require a neutral sandy potting soil that is rich in humus, loose, fertile, and highly permeable. The potting soil should be moist but slightly dry; do not let it become waterlogged and wet for long periods or rainlogged. Geraniums are usually propagated by cuttings, and cuttings taken in spring and autumn root easily. In early March, combined with pruning, take indoor pot cuttings; the survival rate is high, and by autumn of the same year they can grow vigorously and bloom. Autumn cuttings bloom the following spring. After May, high temperatures accompanied by high humidity make cutting survival low, and they often rot easily. Both new and old branches can root as cuttings, but taking from one-year-old strong branches cut at the branching point from the base makes a small wound, calluses quickly, and roots easily. Cuttings are 7 cm to 8 cm long; keep 1 to 2 small leaves at the top, cut the base flat below the node with a sharp knife, and insert into clean fine sandy soil to a depth of 3 cm. Water thoroughly 4 hours after insertion, then keep the potting soil moist, neither too dry nor too wet. In early spring, place in a warm, bright indoor spot. At about 20°C room temperature, roots will develop in about 1 month. Then divide and pot them, using ordinary potting soil in small pots to grow the seedlings; when the seedlings grow strong and white roots emerge from the drainage holes at the bottom of the pot, use fertilized potting soil with some crushed hoof pieces as base fertilizer and repot into chrysanthemum tub pots for final planting.

Geraniums grow quickly and need repotting once a year to add soil and fertilizer, usually from February to early March in early spring. First prune hard, leaving only 3 side buds at the base of each branch, then remove from the pot, pull away the surrounding old and decayed roots, and replace with new fertilized potting soil and apply base fertilizer. After new branches appear in early April, apply a dilute organic liquid fertilizer once a week; by late April, move them outdoors and they will bloom one after another. In early June, move them to the inner side of a balcony in diffused light. For courtyard care, move them under tree shade, on the east side of a house, or under a shade frame. Note that when the soil surface of small pots turns white, or when the soil 1 cm below the surface in large pots feels moist, water them. In July to August, during high temperatures, spray water frequently to cool them and keep the surrounding environment humid; do not let water accumulate in the pots. Move indoors before the early frost arrives in mid-October. In winter, keep room temperature no lower than 12°C, with sufficient light and fresh air, and they will bloom continuously. For professional cultivation to supply large quantities of flowers for the "May Day" holiday, prune heavily in late autumn, move into a low-temperature room (below 10°C), keep light sufficient, control water to maintain moisture, and care with moderate ventilation. In spring, as the temperature rises naturally, the plants grow and develop robustly and can bloom for the holiday.