What are the methods of planting desert rose seeds of Apocynaceae? Why do the leaves turn yellow? When will the seeds be sown?

Desert rose, also known as Tianbao flower, likes high temperature, dry and sunny environment, is resistant to heat and cold, is very beautiful when it is in full bloom, and is often cultivated and ornamental. People like to cultivate it as a potted plant, so do you know the methods of planting desert rose seeds? Why do the leaves turn yellow? When will the seeds be sown? According to the encyclopedia data, desert roses are recommended to be sown in summer and the germination temperature is 21 ℃. It takes about 25 days to take root and the potted plants are cut off 45 days later.

Seed planting method of Desert Rose

1. Planting

Desert roses are native to dry deserts and can withstand extremely hot weather. Desert roses lose their leaves to sleep when the temperature is too low or when there is a lack of water. Proper pruning can promote branching and flowering, which can be pruned when the branches of desert roses are more than 30cm long, usually every two years. Desert roses need plenty of sunshine, which can make plants grow too long, thin and prone to disease, and are not easy to blossom. However, seedlings or plants that have just changed pots should not be exposed to the sun, and should be slightly shaded (25-30% shade) at noon in a dry, hot summer. Desert roses bloom at a temperature of 20-35 ℃ and can blossom all year round in the tropics. The optimum temperature for growth was 22 ℃-30 ℃, stopped blooming above 38 ℃, and could withstand 40 ℃ high temperature. Dormancy occurs when the temperature is below 12 ℃ and the overwintering temperature is 10 ℃.

2. Reproduction

Desert roses can use cuttings, sowing, rootstock grafting or high pressure branches. Sowing is the most suitable time for spring, and it will grow faster. Summer and autumn are also possible, but sowing in winter and rainy season should be avoided. The seed should be sowed as soon as possible after harvest in order to maintain its freshness. If it cannot be sowed within a short period of time, it should be sealed and stored in the refrigerator. Take it out when sowing, the longer the seed will germinate, the lower the germination rate. It is best not to store it in the refrigerator for more than 3 months. [2]

As for the high pressure method (Air-layering), it should be carried out on warm and humid days from spring to summer. Because the juice of desert roses is poisonous, wear rubber gloves and keep the juice from touching your eyes and mouth. First of all, select the mature and sturdy branches, and use the sterilized knife to cut around the branches where they are going to be broken in the future. the wound should cut through the bark to the woody layer, but the branches should not be cut off; cut another circle in the same way at an interval of about two centimeters. Another straight cut between the two circles is to reach the wood layer through the bark and make a straight cut as an opening to peel off the bark layer between the two circles until the xylem is exposed. If the cortex is not completely stripped, it will affect the hair root. Then air-dry the wound for a day. After the wound is air-dried, soak the water moss thoroughly in clean water, then squeeze the excess water dry and set aside. Cut a transparent plastic bag to fit the peeled part of the bag and water moss. Use a young rope to tie one end of the plastic bag about one to two centimeters below the incision of the first knife, then wrap the water moss around the wound and cover the wound completely. Then, about one to two centimeters above the incision of the second knife, tie up the other end of the plastic bag with a young rope. The plastic bag should not expose the opening so as not to lose moisture. Usually after 20 to 30 days, the incision begins to take root. During the period, it is found that the water moss is dry, the young rope at the upper end can be untied, proper water is injected into the opening and re-tied, but do not pour too much water, as there is no stagnant water at the bottom of the plastic bag. The new roots will grow after about 30 to 50 days. At this time, the plastic bags and water moss can be removed, and the rooted branches can be cut off and transplanted. When transplanting, first lay gravel or ceramsite as a waterproof layer on the bottom of the basin, then add about 1/3 soil to it, and then spread the roots in all directions as far as possible in the basin, add the rest of the soil, and place it in a bright place. Wait three to seven days before the wound heals before watering. The position should be placed away from the strong sun in the hot summer, or add a shade net at noon in the hot summer, and the basin soil should not be allowed to dry, nor should it be fertilized until the young plants begin to produce new leaves.

3. Watering

Desert roses like a drier environment, so watering can not be much, long-term called fruit will lead to basin soil stagnant water, resulting in rotten roots, but also make branches easy to grow, destroying the original ornamental value.

Watering should be considered comprehensively according to the different weather conditions and cultivation substrates. Generally, watering should be done about 3 days in spring and autumn, 1-2 more days in summer, less watering in winter and once a week.

4. Fertilization

Desert rose growth period more phosphorus and potassium fertilizer, less nitrogen fertilizer, because nitrogen fertilizer can cause excessive growth of branches and leaves, and inhibit plant growth, when the plant enters the growth and reproduction period, mainly phosphorus and potassium fertilizer, stop using nitrogen fertilizer.

Generally stop fertilization in the flowering period, desert roses bloom for a long time, so they will consume a lot of their own nutrients, you can appropriately supplement some quick-acting fertilizers, but the concentration is not too high. Fertilization should be applied every 2-3 weeks during the period of exuberant growth, and should be stopped during the winter dormant period.

5. Lighting

Desert roses are suitable to grow in a sunny, warm and adequate growth environment, and generally do not need shading, so desert roses can be maintained in places with sufficient light, but the summer light in the south is relatively strong, so pay attention to observe the leaves and take good care of them. can be shaded properly.

Why the leaves of desert roses turn yellow

Environmental change

Desert rose is often classified as succulent plant, its stem is large, can survive in dry environment, desert rose is not resistant to wet environment, so if too much watering, or rainy season let it too much rain, coupled with poor air circulation, weak light, it will lead to desert rose leaves yellowing, if serious will also lead to the phenomenon of whole desert rose rot and death.

Solution.

We need to understand its growth habits in daily maintenance, and reasonable maintenance according to the disease to prevent occurrence.

Too much watering

Too much watering is also an important reason for yellowing leaves, desert roses are not resistant to moisture, so watering should not be too much, otherwise it will cause stagnant water in the roots, lead to rotten roots, and make the leaves yellow and fall off, or even wither.

Solution.

Cut off the rotten roots, and pay attention to the reasonable watering of desert roses, do not make too much watering, watering less, desert roses resistant to drought, so do not need too much water.

Low temperature fertilization

The winter climate is cold, the temperature is low, the desert rose enters the dormancy period at this time, it will have the dry withered leaf situation to appear, is in order to reduce own water evaporation, carries on the self-protection, at this time fertilization should not be too much, not too thick, otherwise it will cause the leaves to turn yellow or even die.

Solution.

Keep the right temperature, the amount of fertilizer is reasonable, not too much, it is best to put the desert rose in the greenhouse for cultivation.

Poor ventilation

Desert roses like to grow in a warm and ventilated environment, and poor ventilation will cause rotten roots and leaves to turn yellow.

Solution.

Desert rose potted plants will be placed in an indoor ventilated position, which is conducive to balcony, windowsill and other positions for breeding.

Disease and insect invasion

Diseases and insect pests are also an important reason for the yellowing of desert rose leaves, and its main diseases and insect pests are shell insects, which will lead to the shedding of the whole plant, growth stagnation and even death.

Solution.

If shell insects are found, 2000 times of omethoate EC should be used in time for spray control.

Time: 2019-03-18 Click: