Hydrangea, or Hortensia, is a genus of flowering deciduous shrubs, less often trees or vines. Most hydrangea species are intended for outdoor cultivation in open ground, while more cold-sensitive species are cultivated in greenhouses or at home as potted plants. They usually bloom in spring from March to May and for this reason symbolize Easter celebrations. Like other hydrangeas, Hydrangea macrophylla has flowers gathered in large, dense, spherical inflorescences up to 20 cm in diameter. The leaves are large and numerous. When grown in the open, the plant can reach 4 meters in height. On acidic soil, the flowers are blue, on alkaline soil – pink of various shades, even white. There are over 500 varieties of hydrangeas that can be grown as potted plants. According to flowering periods from July to September, hydrangeas are divided into early, semi-early, and late.
Most often, the flowers of hybrids and varieties have white, numerous shades of pink, red, or blue-blue color. Almost all classic and common varieties come from France. For example, Miracle, whose flowers can be of various tones (pink, red, white; early and semi-early); Sister Teresa (white; late); Europe and Benelux (pink; semi-early); Red Riding Hood and Alpencluchen (red; semi-early).
Cultivation and care
Hydrangea macrophylla is grown as a flowering plant indoors and outdoors on balconies or terraces. For balconies and terraces, the plant is first kept indoors at maximum lighting for 2-3 weeks, and only then is it exposed to fresh air. However, after 2-3 years of staying in a pot, it is recommended to plant it in a garden, otherwise, it dies.
The plant loves fertile, loose, and sufficiently moist soil with an acidic reaction of the medium. The pH value (soil acidity) should be 5.0-6.0 for ordinary varieties and 4.5-5.0 for hybrids, whose flowers can be given a blue hue. During the growing season, mineral complex fertilizers are added to the water for irrigation once a month in an amount of 20 g per bucket (30 g of iron chelate is also added there from time to time). The flowering period falls on the summer months, but if you want it to start earlier, in the spring, start forcing in winter. The plant is placed in a bright greenhouse with a temperature of 6-8 ° C, gradually increasing it to 18-20 ° C, and kept in these conditions until flowering. In spring, forced hydrangeas are pinched 1-2 times.
Hydrangea macrophylla is a moisture-loving plant that tolerates shading well. When grown in the ground, it is watered abundantly, sprayed with water, and excess shoots are removed in pinched plants. In July, it is fed several times with phosphorus-potassium fertilizers and an infusion of mullein or other organic fertilizers.
Location
Indoors, hydrangea should be kept in the brightest place or near a window, but always away from heat sources. If it is grown outdoors, it is better to place it in partial shade, although the plant blooms more profusely in the sun with sufficient moisture.
Temperature
The optimal temperature for growth and development is 15-20 °C. Some species and varieties are quite frost-resistant and can be grown outdoors with light shelter.
Maintenance
Faded inflorescences, as well as damaged parts of the plant, are removed. In autumn or spring, last year’s branches are cut, leaving 1-3 pairs of buds.
Propagation
Hydrangea is propagated by dividing bushes, layering, offspring, cuttings, and in selection – by seeds. For cuttings, lateral shoots or ground shoots of forcing plants are taken. The lower leaves are removed from the cut cuttings and planted in a box with a substrate of peat and sand (2:1). After rooting, they are transplanted into pots with a mixture of peat and sod land with the addition of sand and organic or mineral fertilizer. Later, they are transplanted into larger containers and planted (dug in) in open beds.
Diseases and pests
Infection with fungi (Pythium and Rhizoctonia) can be prevented by pre-sterilizing the soil. If the plant is affected, it remains only to discard it. Leaves and shoots can be damaged by gray mold of vegetables (Botrytis cinerea) and powdery mildew of grapes (oidium). In this case, appropriate fungicides are used. Hydrangea is affected by pests (both root and above-ground parts of the plant): aphids, thrips, mites, and nematodes. They get rid of them with the help of appropriate chemical preparations. With forcing, if the initial temperature of the plant content is above 12-15 °C, the buds fall off. With chlorosis, the new above-ground organs of the plant and the leaves located at the ends of the shoots turn yellow. They get rid of it by establishing the correct pH level and adding iron chelate to the soil.
Purchase
Indoor hydrangeas can be purchased starting in March in flower shops, florists, and garden centers. You should choose compact plants that have just entered the flowering phase.