Generic meaning of weeds connotes fullness of iniquity, works of the flesh, neglect, worry, laziness.
To dream of applying herbicides on your farm is a good omen of fruitfulness to come.
If you observed weeds in a garden or farm in the dream it is a warning against undesirable companions who may damage your reputation. Pray against powers of darkness assigned your destiny.
To destroy or hoethem stipulates you can be sure your clouds shall have silver linings.