Kalanchoe turns black as soon as autumn comes? If you continue watering like this, you will definitely die!

Why is Kalanchoe prone to black rot?

Causes of Black Rot

In summer and autumn, the weather is hot and humid, and the heat has not yet completely dissipated. During this period, the Kalanchoe has just passed its dormant period, and its roots are relatively weak. If you water it too much or expose it to the sun, the roots will be suffocated and will soon rot.

Black rot symptoms

The black rot of Kalanchoe starts from the middle of the stem and then quickly spreads to the roots and leaves, causing the rhizomes to rot, the branches to hang upside down, and the leaves to become soft and wrinkled. In severe cases, they will fall off at the touch.

Some people mistake the black spots and water rot on the leaves of Kalanchoe for black rot, and believe that black rot can be treated, which is unscientific. This is usually not black rot, but black spot disease.

In fact, even if black spot disease is not treated with medicine, stopping watering and making its growing environment dry can stop it from spreading.

What should I do if Kalanchoe has black rot?

1. Rapid isolation

Black rot is highly contagious. Once discovered, the diseased plants must be isolated immediately and the rotten stems and leaves must be cleaned up.

2. Pruning and disinfection

In the early stage of the disease, the root system is generally not damaged. At this time, you only need to cut off the diseased stems and leaves, and apply carbendazim or thiophanate-methyl powder on the wound to avoid further infection.

If the black rot is very serious and the root system is completely rotten, it is necessary to change the pot and soil. After removing the diseased plant from the pot, cut off the intact upper part, soak it in a solution of carbendazim, and then disinfect it before re-cutting. The original soil must be thrown away and the original pot must be thoroughly disinfected.

3. Prevention is better than cure

The key to disease is prevention. During the sensitive season, it is best to spray a fungicide on the leaves once after each watering (either carbendazim or thiophanate-methyl will do). Also spray after rain.

In summer and autumn, not only mature Kalanchoe are prone to black rot, but newly cut Kalanchoe cuttings are also prone to black rot. Now Huahua will teach you how to avoid black rot in cuttings!

How to avoid black rot when propagating Kalanchoe cuttings?

The reason for black rot in cuttings is very simple: too much water! Therefore, the key to preventing black rot lies in how to water correctly!

1. Change watering to spraying

The root system of cuttings is relatively weak and has insufficient water absorption capacity. Flooding of the soil can easily lead to lack of oxygen and root rot. You can change watering to spraying, and use a sprayer to wet 2 cm of the soil surface.

2. Control the amount of water

For a flower pot with a diameter of 10 cm, spray about 15 ml of water each time; for a flower pot with a diameter greater than 20 cm, spray 30 ml of water each time, and spray once every 5 to 7 days.

3. Better dry than wet

The principle of watering Kalanchoe is: it is better to keep it dry than wet. If the plant lacks water, at most one or two dead leaves will be produced, but it will never die. However, if there is too much water, not only black rot will occur, but other diseases will also occur.

Precautions

1. The potting soil should be breathable

No matter what kind of flowers you grow, the most important thing is that the potting soil is breathable. The stuffy potting soil not only creates conditions for bacterial reproduction, but also reduces the resistance of the root system. For Kalanchoe, just mix garden soil, cinders or peat, cinders and perlite.

2. Soak the roots before repotting

After autumn, whether you are repotting or transplanting, first rinse the roots with water and then soak them in a solution of carbendazim to reduce the chance of disease.