Why Are Orchid Shoots Rotting? Cause Analysis and Prevention Methods

Many orchid growers may encounter rotting orchid shoots, that is, rotting new shoots of orchids. As long as you look carefully, it is not hard to find the cause. Generally speaking, there are 6 main reasons for rotting orchid shoots, such as water entering the shoot core, bruising, and pest damage. Below we will analyze the reasons in detail:

1) Careless watering or misting causes splashing into the center of the shoot, or the plant is exposed to rain for a long time; combined with insufficient light and not-high temperatures, the water cannot be absorbed; or even after heavy rain the new shoots are soaked in water and drainage is not done in time, causing shoot rot.

2) Careless repotting and division, pruning of old leaves, and routine watering, fertilizing, or spraying pesticides, or accidental incidents, cause injury.

3) When applying liquid fertilizer, it is carelessly splashed into the shoot core and no attempt is made to remove it, causing rot.

4) The mother plant is infected with pathogens and no timely control is carried out; combined with the weak disease resistance of young shoots, this leads to shoot rot.

5) Scale insects, aphids, and red spider mites suck the sap of the shoots, and rats bite and eat the sweet tender shoots and young leaves, causing damage.

6) Root rot causes shoot rot.

Prevention methods for rotting orchid shoots:

(1) For routine watering and fertilizing, it is best to use a ladle or scoop to pour along the edge of the pot; avoid spraying the orchid plant with a hose, to prevent mud and dirty water from splashing into the center of the shoot. During the seedling stage, try not to spray water on the orchid plant. If spraying is necessary, a fine-hole nozzle must be used, and the water droplets must not be too large; it is best if the leaf surface does not drip. If a coarse-hole nozzle is used, the new shoots must be covered.

(2) In summer and autumn during the plum rain and continuous overcast-rainy seasons, pay attention to preparing for rain protection. Either build a temporary rain shelter over the orchid plants with nylon cloth or plastic film, or move the orchid plants to a place where rain cannot reach them before rainfall. Also pay attention to watching the weather forecast. Once there is heavy rain or extremely heavy rain, emergency measures must be taken for prevention; if there is no time to avoid the rain, after the rain drain the accumulated water from the pots in time.

(3) In the intense heat of midsummer, prevent strong light exposure, high-temperature baking, and poor ventilation; in the severe cold of winter, pay attention to cold protection and warmth, and avoid freezing damage; in winter, the water temperature for watering should be close to the air temperature and must not be too high, otherwise it is easy to cause scalding.

(4) Sterilize and kill insects in time. During the orchid growth period, regularly spray carbendazim, thiophanate-methyl, or other sterilizing agents to prevent problems before they occur. Once pests are found, promptly spray insecticides such as dimethoate, imidacloprid, methidathion, and fenitrothion. In daily work, also do a good job of safety and security in the orchid garden to prevent human-caused and accidental injuries.