Abstract: In two experiments, seeds of tomato (Solanum esculentum L.) cultivar 'Celebrity' were planted in four root substrates (Grower's Mix 20, Fafard 4P, Johnny's 512 Select and Sunshine Planter's) in 72-cell plastic plugs trays using different cover materials. In physical property evaluations, the four substrates had similar total porosity. However, Johnny's 512 Select had the highest container capacity and bulk density while Fafard 4P and Sunshine Planter's had the largest air space. There was some seasonal variation between the germination and growth results of the two studies. The use of root substrate, coir, or vermiculite resulted in better germination than leaving the seeds uncovered, with the exception of the seeds germinated in Johnny's 512 Select in Experiment 1. Also, in Experiment 1, tomato seedlings were the tallest and heaviest when grown in Grower's Mix 20. Using newspaper to cover seeds reduced germination in Experiment 2. Tomato seedlings grown in Grower's Mix 20 and Johnny's 512 Select were equal or greater in shoot height or weight as compared to those grown in the conventional substrate Fafard 4P.