<p><strong>Background: </strong>The vermicompost provides nutrients and increases the biological activity of the soil, while the mulch provides humidity and regulates the temperature by modeling its biological activity, and influences the morphology of the plants, however, studies on the effects of use are scarce. combination of vermicompost and padding in mycorrhizal functionality. <strong>Objective: </strong>To evaluate the effect of plastic mulch and vermicompost on the colonizing potential of arbuscular mycorrhizal fungi in Italian squash (<em>Cucurbita pepo</em> L. cv. 'Grey Zucchini') during winter-spring (W-S) and autumn-summer (A-S) cycles, in the field<strong>. Methodology: </strong>The study was developed in a block design of fixed effects in factorial arrangement with three repetitions to know the effect of the second-degree interaction between the factors: padding color, climatic period and fertilization variant on the colonizing activity of AMF and morphology foliar of <em>C. pepo</em>. A principal component analysis (PCA) was developed to know the contribution and relationship of the variables of chemical composition of the soil and vermicompost within each climatic period, on the colonizing activity of AMF in a cultivation system with padding. <strong>Results: </strong>The PCA showed in the W-S period effects due to the use of mulch in colonization by arbuscules (-0.84), while the contributions of vermicompost favored colonization by hyphae (0.95). In A-S, the colonization by hyphae was affected (-0.82) by the plastic padding, but the use of vermicompost, favored the colonization by vesicles (0.87) and arbuscules (0.97). <strong>Implications: </strong>The present study contributes to a better understanding of the mulch-activity relationship of AMF and mulch-crop under fertilization variants, being considered useful for the improvement of the production systems of <em>C. peppo</em> with the use of mulch and its effect on the biological performance of AMF. <strong>Conclusions: </strong>It is concluded that the effect of mulch on the biological activity of AMF varies by the climatic season in which it is used, likewise the use of mulch in A-S does not favor the biological activity of AMF, nor foliar development of the <em>C. pepo</em>.</p>