Poncirus

Family. Rutaceae.

Origin. Japan, China.

Description. The genus Poncirus consists of only 1 species of plants - deciduous shrubs or low trees. The stems are branching, prickly, green, but become woody with age. The leaves are green, thick, hard, alternately arranged, complex - consisting of 3 elliptical segments. In autumn the foliage turns yellow and falls off. When damaged, the leaves emit a pleasant smell. The flowers are solitary, axillary, white or cream, have a citrus-like aroma, and often appear before the foliage. After flowering, the plant produces round green fruits with a thick and rough skin, which turn orange when ripe. Unlike most citrus fruits, poncirus fruits are covered with a very pleasant fluff.

Height. In indoor culture it is regulated by pruning.

Cultivation

Temperature conditions

The optimal temperature range is from 18 to 24 ° C. At night, it is desirable to lower the temperature to 13 – 15 ° C. At higher temperatures, it is necessary to increase watering and air humidity. At temperatures below 13 ° C, plants slow down their growth and enter a dormant period.

Lighting

Maximum possible lighting with direct sunlight in the morning and evening hours for 5-6 hours daily. Light shading is possible only on very hot summer days. The pot should be turned approximately ¼ turn every week so that the crown of the tree develops symmetrically.

Care

As growth begins, trim off shoots that are too tall or weak and do not promote the appearance of lateral branches. Citrus plants can be placed outdoors in the summer. Remember that all species should be moved gradually so that they get used to new living conditions.

For the beginning of fruiting and simply harmonious development of citrus, it is very important to correctly form the crown. The first pinching of rooted cuttings or plants obtained from seeds is carried out when they reach a height of 20 cm. Shoots extending from the main trunk of the tree are called first-order shoots - they are pinched when they reach a length of about 20 cm. This procedure, like others, makes sense to carry out when the branches are still soft - so they can simply be pinched off, and the plant will not even notice it. In the place where the 1st order shoots were pinched, a fork of 3rd order shoots usually appears - they are shortened when they also reach a length of 20 cm. Accordingly, 4th order branches will form on their tops - they are left about 10 cm long. The first flowering will occur on the 4th and 5th order shoots.

Trim old and diseased branches in a timely manner - all work should be carried out only with sharp, sterile pruners and, if necessary, sprinkle the cut areas with crushed activated carbon. Do not place plants near heating systems - they will react in the fall with abundant leaf fall. 

Substrate

Ponciruses adapt well to most types of soil, even those poor in nutrients. The soil should consist of peat, leaf mold, perlite or vermiculite to improve drainage and have a slightly acidic pH.

Feeding

Fertilize every 2 weeks in spring and summer.

Purpose

Citruses are able to disinfect the surrounding atmosphere. Poncirus is often used as a rootstock for cultivated representatives of the family, as it is quite unpretentious.

Flowering time

April May. 

Air humidity

If the air in the room becomes too dry or the temperature is high, increase the humidity with a room humidifier or by placing the pot on a tray with wet pebbles. Make sure that the water in the tray does not touch the bottom of the pot - this can lead to rotting of the root system. You can spray the leaves with water at room temperature. Poncirus like well-ventilated rooms with a constant flow of fresh air, but without cold drafts.

Soil moisture

The soil should be evenly moist, but not waterlogged. Between waterings, slightly dry the top layer 3-5 cm thick. In autumn, the frequency of watering is slightly reduced. 

Transfer

Young trees are repotted annually as they grow into larger pots. Mature specimens need to be repotted every 2-3 years. For larger tub plants, simply replace the top layer of soil with fresh soil each year.

Reproduction

Poncirus, unlike most citrus fruits, is more often propagated by seeds and in its natural habitat often forms self-seeding. Stem cuttings about 10 cm long are rooted in spring and summer, using growth hormones. Rooting is carried out under the cover of a transparent plastic cap or glass for 6-8 weeks.

Pests and diseases

Citrus trees are susceptible to a wide range of fungal diseases that affect the roots, trunk and branches, foliage and fruit.

• If the tips of the leaf blades, especially in the winter months, become brittle, brown and dry, then the soil may be over-watered - for such specimens, it is necessary to reduce the frequency of watering.
• Of the fungal diseases, citrus trees can be susceptible to anthracnose if kept in a room that is too warm and very humid.
• Scab can appear as unsightly pinkish-yellow spots on the fruit and small yellow spots on young lemon leaves.
• Sooty fungus appears as a black coating on the leaves and shoots of the tree.
• With too frequent and abundant watering, as well as insufficient drainage, the bush can be affected by root rot. With the onset of this disease, trees will lose leaves in large quantities.
• If the poncirus is located too deep and its root collar is sunk into the ground, gummosis may appear, which appears as small transparent drops of resin on the branches.
• Powdery mildew affects shoots and leaves when kept in too cool, humid conditions. This disease looks like a white fluffy coating on the leaf blades.
• Deformation of the leaf blades, a change in their color and general oppression of the plant may indicate the appearance of viral diseases. Trees infected with the virus will most likely die.
• If small, round, brown spots appear on the fruits, surrounded by a lighter, yellowish circle, then the plant may suffer from citrus cancer.

Spider mites may appear as pests. Mealybugs prefer young trees. Whiteflies hide on the undersides of leaves, sucking out the sap. Aphids cause leaves to curl and become crinkled.

Note

With proper care, poncirus can grow and bear fruit in indoor culture for many years. The fruits are edible, but have a bitter-sour taste. The stems have long thorns - up to 3 - 5 cm; when working with it, protect your hands with gloves and be careful.