Superabsorbent hydrogels based on carboxymethyl cellulose and acrylic acid with clay montmorillonite (MMT) were synthesized using gamma irradiation. The effects of the radiation dose and MMT concentration on the physical properties such as gel fraction (%) and swelling behavior of the hydrogel were studied. Moreover, the morphological, structural, and thermal properties of the prepared hydrogels were characterized by scanning electron microscopy, X‐ray diffraction, and thermogravimetric analysis. The swelling behavior of the as‐prepared hydrogels in water, salt solutions, and different pH media was studied. The hydrogels showed higher swelling percentage in distilled water than in salt solutions. In addition, they exhibited higher swelling in basic medium rather than in acidic medium. Water retention (%) of these superabsorbent hydrogels decreased as the concentration of MMT increased in the hydrogel. The 1% MMT hydrogel could be considered as a water‐managing material for agriculture and horticulture in desert and drought‐prone areas.