Rhododendron, azalia - Rhododendron simsii
In gardening practice, this species is called azalea. It is an evergreen shrub with elliptical oval leaves, hairy, broadly funnel-shaped flowers 2–4 cm in diameter, single or full gathered in a few umbels.
Early varieties, like for example. "Petrick Alba" - about white flowers, "Madame Petrick" - full pink. "Theodor Findeisen" - with pale pink flowers, they bloom in December and January. Medium-early varieties, e.g. "Vervaeneana", about pink flowers, green pink or red rushes at the end of January, February. Late varieties, which bloom in March-April, the most common are: "Hexe" with scarlet flowers, "Ernst Thiers" - about full flowers, dark red and "Niobe" with white flowers, full.
Azaleas are sold singly in pots or baskets, or 2-3 pieces in larger baskets.
Only these plants can grow azaleas, which have water that does not contain calcium compounds and have a source of heather earth or beech and oak leaf soil.
Azalea reproduction. Azaleas are propagated from cuttings or by grafting. These varieties (e.g. ,,Witch", "Ernst Thiers"), whose shoots are well-rooted, we propagate by cuttings. The cuttings are prepared from the tops of the shoots cut in the spring crown formation in March until the first days of May or torn off with a heel if they knocked out around the flower buds of driven plants. Cuttings 4-6 cm long should be prepared from healthy shoots, well formed. We place them in a multiplier with a spacing of 3X4 cm in sand mixed with the same amount of heather earth or peat. Cover the seedlings with windows, we shade, we spray one or more times a day and keep the temperature at 18-22 °. In a warm and humid environment, they should take 6 to 7 weeks to take root.
We plant the rooted plants in the Belgians, frames or on window sills in a cold greenhouse with a spacing of 6X6 cm to heather soil or to leaf soil with the addition of peat and sand. The soil should be acidic (pH 4,5—5), and water for watering, as already mentioned, must be soft. For several days after planting, the crates remain covered with windows and we shade them on sunny days. After a week or so, the azaleas were kept to air more and more, then remove the windows.
In July, the top is pinched at a height of 15-20 cm, to cause the plants to branch out.
In summer, azaleas tolerate even strong sunlight if they are watered abundantly, preferably with a rain shower. Insufficient winter moisture causes the leaves to fall.
Azalie, which stayed in the frames or Belgians throughout the summer, in mid-September, we plant them on the tables in the greenhouse, spaced apart 10 X 10 cm to the heather soil or leaf soil with the addition of peat and sand. Fresh soil should be used with each transplant, and the old one should not use more than Vs.
In this way, we also reproduce Rhododendron concinnum used as a rootstock when grafting azaleas. Rooted plants are planted in pots with a diameter 9 cm, in which they remain to be vaccinated. We do not prune them so that they develop one straight shoot.
Propagation by vaccination. If the seedlings of R. concinnum were prepared early enough, in February-March and they grew luxuriantly and developed a strong root system, they can be used as washers in the same year. Weak plants will not be suitable for inoculation until January. The most appropriate time to vaccinate azaleas is from mid-June to early August. Length slips 6-8 cm is cut from well-formed tops of the shoots: they are of the same thickness as the washer and then grafting is carried out by application. If the washer is thicker, we graft into a wedge. Trim the pad at a height of 10-15 cm in place, in which the color of the bark changes from green to brown. The cut planes of the rane and the rootstock must fit snugly. We tie the vaccination site with cotton, but we do not apply ointment. We place the plants in the morning-incandescent lamp on the tables, on which we place them diagonally - with either side up or straight. A deckhouse should be made of boards on the tables 2,5 cm thick at a height of 20-25 cm, so that the plants can be tightly covered with frame windows or foil. The temperature should remain constant, between 20 ° and 22 °. Sprinkle the plants with a nebulizer spray several times a day and shade them: After 3 weeks, when the scion and rootstock begin to heal, we begin to carefully ventilate. After 6-8 weeks the growing process should be completed and then the azaleas are planted on the windowsill in a cold greenhouse with spacing 10 X 10 cm. At the same time, we loosen the bond. Remove leaves and possible side shoots from the rootstock, and peel the scion over 4-5 leaves, to start branching.