1、 Poor maintenance

Cause: it is generally caused by poor ventilation or excessive watering. This situation will improve after improving environmental problems and conservation methods

Solution: move the plant to a well ventilated place, reduce watering at the same time, and pour water after the soil is dry

2、 Flower soil partial acid

Reason: too much ferrous sulfate is used, resulting in high acidity of basin soil. Further affect the growth of gardenia, resulting in blackening of leaf tips

Solution: if there are few black leaves, wash the basin soil with clean water. If there are many black leaves, replace the basin and soil in time, and check whether the root is burned. At the same time, reduce the spraying times of ferrous sulfate, generally once to once every two months

3、 Soil alkaline

Reason: Gardenia likes acidic soil. If the soil alkali content is high, it will also cause the leaves to blacken

Solution: add a certain ferrous sulfate solution to the basin soil. It can be mixed with water and sprayed on the leaf surface once a month. Too frequent will also be detrimental to growth

4、 Occurrence of pests

Reason: root knot nematode is one of the common pests of gardenia, and it is difficult to find because it is mostly in the root

Solution: check the root to see if there are root nodules, if any, cut them off, and use pesticides to kill insects at the same time