It means do not judge before it's time. If you pull up one bad root, good roots may be pulled up in the process. Example: You think you are doing good by going against a pastor whom you think is not preaching the word. The charges may or may not be true. But even if they are true, you bring down a pastor, and others will fall down as well. One should be very careful, before they make accusations against the Lord's anointed or anyone else in authority.