Asherah, and its plural form, Asherim, from the Hebrew word pronounced ash-ay-raw, refers to a pagan goddess, also known as Astarte to the Canaanites and Ishtar to the Assyrians and Babylonians. The common symbols of the cult were tree trunks with all of their branches removed and images carved into them. These standing tree trunks were the reason that some versions of the Holy Bible translate the actual original word of the Holy Scriptures, Asherah or Asherim, as grove or groves e.g. for 2 Chronicles 15:16, from the RSV and KJV:
"Even Maacah, his mother, King Asa removed from being queen mother because she had made an abominable image for Asherah. Asa cut down her image, crushed it, and burned it at the brook Kidron." (Revised Standard Version)
"And also concerning Maachah the mother of Asa the king, he removed her from being queen, because she had made an idol in a grove: and Asa cut down her idol, and stamped it, and burnt it at the brook Kidron." (King James Version)
"Thou shalt not plant thee a grove"
As the Scriptures above describe, the Israelites, from ordinary people to royalty, were greatly corrupted by the cult of Asherah (Jerusalem's Valley Of Kidron, referred to in the verses above, is shown in the photograph). The Lord commanded them not violate The Second Commandment, but they stubbornly and foolishly often did it anyway (just as millions of people still do today, some even in Christ's Name - see the Fact Finder question below), despite the efforts of righteous people and God's true prophets to rid the people, who claimed to be God's people (see I Did It My Way...), of it.
"Thou shalt not plant thee a grove of any trees near unto the altar of The Lord [see YHVH, Adonai, Jehovah, LORD] thy God, which thou shalt make thee. Neither shalt thou set thee up any image; which The Lord thy God hateth" (Deuteronomy 16:21-22 KJV)
"And it came to pass the same night, that The Lord said unto him, Take thy father's young bullock, even the second bullock of seven years old, and throw down the altar of Baal that thy father hath, and cut down the grove that is by it: And build an altar unto The Lord thy God upon the top of this rock, in the ordered place, and take the second bullock, and offer a burnt sacrifice with the wood of the grove which thou shalt cut down. Then Gideon took ten men of his servants, and did as The Lord had said unto him: and so it was, because he feared his father's household, and the men of the city, that he could not do it by day, that he did it by night. And when the men of the city arose early in the morning, behold, the altar of Baal was cast down, and the grove was cut down that was by it, and the second bullock was offered upon the altar that was built." (Judges 6:25-28 KJV)
"And Ahab the son of Omri did evil in the sight of The Lord above all that were before him. And it came to pass, as if it had been a light thing for him to walk in the sins of Jeroboam the son of Nebat, that he took to wife Jezebel the daughter of Ethbaal king of the Zidonians, and went and served Baal, and worshipped him. And he reared up an altar for Baal in the house of Baal, which he had built in Samaria. And Ahab made a grove; and Ahab did more to provoke The Lord God of Israel to anger than all the kings of Israel that were before him." (1 Kings 16:30-33 KJV)
Fact Finder: What is The Second Commandment?
See also The Second Commandment