The Shield is: Gules, a five-petalled rose argent, barbed vert.
Translation: A rose connotes Beauty.
Crest: The rose of the shield.
The Polish family name Grzybowski is classified as being of habitation origin. The family name may be traced to any of several Polish towns and villages with names such as "Grzybow", "Grzybowe", and "Grzybowa", which were themselves derived from the Polish word "grzyb", signifying "mushroom".
Surnames ending in -owski usually derive from place names ending in -y, -ow, -owo, -owa, and so on. There are at least 17 villages in Poland named Grzybow, Grzybowa, Grzybowo, etc., (probably more too small to show up on maps), and the name Grzybowski originated as a reference to association with any or all of them; it could have meant "family from Grzybow/o etc.," it might have referred to a noble family that owned the estate there, peasants who worked on an estate there, a man who traveled there often on business, or so on. It is virtually certain the name was adopted by many different families in many different places. The root of the place name is grzyb, "mushroom," so all these places got their names because of some association with mushrooms, and the surname just means basically "one associated with the place of the mushrooms."
Sources: Family Heritage Shop
Polish Surnames: Origins and Meanings
William F. "Fred" Hoffman