Breakdown of A veces las raíces salen de la maceta y ensucian el suelo del balcón.
Questions & Answers about A veces las raíces salen de la maceta y ensucian el suelo del balcón.
Spanish uses the definite article much more often than English.
Here, las raíces sounds natural because we are talking about the roots in a general-but-concrete way: the roots of the plant in that pot. In English, you might simply say roots, but Spanish often prefers the roots in this kind of sentence.
So las raíces is not unusually specific; it is just normal Spanish usage.