A Complete Guide to Common Pests and Diseases of Gardenia and Their Control Methods, Worth Saving

Gardenia flowers are pure white and elegant, with a rich yet refined fragrance, calm and cool, like gentle breezes blowing through midsummer, and are deeply loved by people. So what are the common pests and diseases and their control methods in the process of growing gardenias?

1. Gardenia leaf spot

1. Symptoms

Leaf spot is a disease caused by fungi and mainly damages the leaves of gardenia. When it occurs, the plant develops round lesions 2-4 cm in diameter, yellow-brown in color, and many small black spots appear along the leaf edges. A humid environment around the gardenia increases the likelihood of this disease.

2. Control methods

During care, pay attention to ventilation and light transmission, water appropriately, and reduce air humidity. If conditions permit, the plant can be placed outdoors for care.

In the early stage of the disease, promptly remove diseased leaves to prevent spread. Separate the affected gardenia from other plants to avoid cross-infection.

When the disease occurs, spray Bordeaux mixture or zineb solution. Spray once every 7-10 days, and 3-4 consecutive sprays can cure it.

2. Gardenia chlorosis

1. Symptoms

Gardenia chlorosis is a physiological disease that damages the leaves of gardenia. When it occurs, the leaves gradually turn yellow, plant growth slows, and the plant gradually wilts.

2. Control methods

If the plant is found to be turning yellow, spray the leaves or water the roots with a 0.2-1% ferrous sulfate solution. When watering the roots, the concentration can be adjusted higher. Choose the time for spraying after the morning dew has completely dried, and expose the plant to sunlight after watering (or spraying). If the yellowing is severe, spray once a week, but control the spray concentration to avoid burning the roots. After a period of time, the plant's leaves will gradually turn green and return to normal.

To prevent yellowing, during the gardenia's growth period from April to August each year, preventively spray 4-5 applications of ferrous sulfate solution.

3. Gardenia sooty mold

1. Symptoms

Sooty mold mainly occurs between branches and leaves. When it occurs, brown-white lesions appear on the branches and leaves, the branches stop growing, and the plant gradually wilts.

2. Control methods

When the disease occurs, promptly wipe with clean water to remove the white fungal growth from the branches and leaves. Alternatively, spray 1000-1200 times diluted carbendazim and Baume-degree lime sulfur mixture for comprehensive control.

4. Gardenia rot

1. Symptoms

Gardenia rot mainly damages the main trunk of the gardenia. When it occurs, the lower part of the main trunk shows stem swelling and cracking, and the main trunk gradually shrinks and rots.

2. Control methods

After the flowers fall, prune promptly and cut off withered branches. Also thin out branches to reduce nutrient consumption and promote the growth of the main trunk.

If stem rot is found, promptly scrape off the rotted part and apply 5-10 degree lime sulfur mixture several times.

5. Gardenia pests

The pests that harm gardenia include aphids, flea beetles, and hawkmoth larvae. The first two can be controlled with dimethoate and trichlorfon, and the latter can be controlled with 666 powder or caught by hand. In addition, when indoor ventilation is poor in winter and temperature and humidity are too high, gardenias are prone to scale insect damage, accompanied by sooty mold. Scale insects can be scraped off with a bamboo stick or small brush, or sprayed with No. 20 petroleum emulsion plus 100-150 times water for control.