Disease and insect control of Spiraea hemp

Prevention and treatment measures

Leaf spot and angular leaf spot

First of all, this plant usually grows in a relatively extensive manner, and damage caused by pests and diseases is not common. The most common diseases of Spiraea hemp are leaf spot and angular spot. You should use 50% thiophanate-methyl and 1000 times diluted wettable powder (pay attention to the dosage).

Sawfly

There is a leaf-eating pest called sawfly. It is common to see dozens of larvae gathering together to devour the leaves of spirea. It only takes a short time to eat up all the leaves, leaving only the main veins of the spirea intact. This is very serious and affects the healthy growth and ornamental value of the plant. This insect will produce about 2 or 3 generations a year, and will spend the winter by spinning cocoons and pupating in shallow soil. There are other ways to prevent and control this. Use 1000 times diluted 45% propyl bromide, or a mixture of 1500 times diluted Guoguang Yike (20% cypermethrin) + 2000 times diluted Leke (5.7% emamectin benzoate), or 1500-2000 times diluted 40% acetamiprid (Bizhi) to spray to kill the larvae. It can be used continuously for about 2 times, with an interval of about 9 days. Note that medication should be rotated to delay the development of resistance.

Tips

Before growing flowers and plants, of course you need to understand their characteristics and know what to pay attention to. In this way, when problems arise, you will know where to start. They usually have some insects that appear in the early spring, so don’t be too nervous, and there won’t be any problems if you take proper precautions.