Agriculture is the basis of our economic activity. For improving agricultural production greenhouse technology was developed to prevent adverse climatic conditions. Even though higher yield and profit were obtained from greenhouse production compared to open field cultivation farmers were not satisfied with this technique due to the drastic reduction of crop yield with the aging of cladding material. To test this, an experiment was conducted in the instructional farm of Kelappaji College of Agricultural Engineering and Technology (KCAET), Tavanur, Kerala during the period from April to June 2021. Amaranthus variety CO1 was planted inside two greenhouses where one is having cleaned cladding material and the other is an old one. Microclimatic parameters and the biometric observations of crop in both conditions were compared. Mean monthly values of temperature and light intensity were higher inside the cleaned greenhouse than the old one while relative humidity was higher inside the old greenhouse. Crop growth parameters were higher inside the cleaned greenhouse than the old one except the internodal length. From this study, it was clear that the aging of cladding material has a significantly higher influence on crop performance under greenhouse.