I've read that an upright pole or stake is a symbol of Baal worship
Common Symbols of Baal and Asherah
Many symbols were used to represent Baal and Asherah. For the most part, a round object such as a disc or a ball represented Baal as the “Sun God.” Generally, objects that represented Baal were non-stationary. They were mobile and had to be transported by the worshippers. Correspondingly, a hole or a ring represented Asherah. Sometimes, these holes or rings were attached to a denuded or “naked” tree (a pole). These more elaborate Asherah symbols were called “Asherah poles.” These objects were usually stationary.
This latter symbol of Asherah, i.e. the stationary pole, has created some confusion when trying to understand the system of worship and service associated with Baal because Baal was also symbolized through a stationary object or standing pillar. The standing pillar of Baal was known in Hebrew as a matzevah . Today, we call it a “phallic symbol.” Interestingly, matzevah comes from the verb natsav that can mean, “to stand upright or to erect.” To put it plainly, a matzevah was a standing image of a male erection.
If we think about the sexuality inherent in Baal worship, then we can easily understand the meaning of the disc or ball, not only as a representation of the sun or the Sun God, but more tangibly as a representation of the male reproductive capabilities, i.e. the testicles (which are round like balls) and the seed of copulation, i.e. semen. Obviously, the hole or ring of Asherah symbolized the female genitals. If the ring or hole was attached to a pole, then the pole itself symbolized the woman.
In Exodus 34:12-13, YHVH commanded Israel to destroy the altars of the nations, their standing pillars (that symbolized male erections), and their Asherah emblems (that symbolized women and women’s vaginas). “Take heed to thyself, lest thou make a covenant with the inhabitants of the land whither thou goest, lest it be for a snare in the midst of thee: But ye shall destroy their altars, break their images [phallic symbols], and cut down their groves [Asherah poles].” Similarly, we read in Deuteronomy 7:5, “But thus shall ye deal with them; ye shall destroy their altars, and break down their images [phallic symbols], and cut down their groves [Asherah poles], and burn their graven images with fire.” Another similar statement can be found in Deuteronomy 16:21-22. “Thou shalt not plant [establish] thee a grove [Asherah pole] of any trees near unto the altar of the YHVH thy Elohim, which thou shalt make thee. Neither shalt thou set thee up any image [phallic symbol]; which YHVH thy Elohim hateth.” Now you can understand why he hates them so much!
To summarize, the symbols for Baal were the stationary standing pillar (symbolizing the penis), i.e. the phallic symbol, as well as the non-stationary ball or disc (symbolizing the procreative act caused by the movement of semen). The symbols for Asherah were the hole or ring whether attached to a denuded tree (or pole) or not. Commonly, the hole or ring was attached to a pole. In such cases, the Asherah symbol was stationary. http://www.haderek.ca/articles/baal/baal1.htm