  We examine the effects of $f(R)$ gravity on Jeans analysis of collapsing dust
clouds. We provide a method for testing modified gravity models by their
effects on star formation as the presence of $f(R)$ gravity is found to modify
the limit for collapse. In this analysis we add perturbations to a de Sitter
background. Depending on the characteristics of a chosen $f(R)$ model, the
appearance of new limits is possible. The physicality of these limits is
further examined. We find the asymptotic Jeans masses for $f(R)$ theories
compared to standard Jeans mass. Through this ratio, the effects of the $f(R)$
modified Jeans mass for viable theories are examined in molecular clouds. Bok
globules have a mass range comparable to Jeans masses in question and are
therefore used for comparing different $f(R)$ models. Viable theories are found
to assist in star formation.
