Ferry-Morse Seed Company is trying to market worm castings to their customers. Murray State University was asked to compare different percentages of worm castings for use with both bedding plants/vegetables and houseplants. Recommended application rates for worm castings was not to exceed 30%. Two plants were chosen to represent the plant categories deemed important to the consumer: tomato (Lycopersicon esculentum `Rutgers') and spider plant (Chlorophytum comosum). Treatment percentages for worm castings were 0% for a control and 10%, 20%, and 30% were incorporated into a soilless media substrate. Treatment 1 consisted of worm castings/soilless media alone and Treatment 2 consisted of worm castings/soilless media with the addition of Peters Professional All-Purpose 20–20–20 fertilizer at 100 ppm nitrogen. Tomatoes were grown from seed and the spider plant propagules were harvested from greenhouse stock plants and sized into small, medium, and large depending on weight. Tomatoes were harvested at 6 weeks and spider plants at 10 weeks. All tomatoes in Treatment 1 had poor visual consumer quality. Visual quality for Treatment 2 tomatoes was best in 20% and 30%. No significant differences were found in Treatment 1 regarding shoot and root weights. Treatment 2 showed significant differences in dry and fresh weight between the control and 20% and 30%. There were visual quality differences with spider plants in Treatment 2 and also significant differences in shoot and root weights between control and all percentages of worm castings in Treatment 2. Based on plant performances, a recommendation to Ferry-Morse Seed Company was to market worm castings in conjunction with a regular fertilizer schedule for maximum plant quality.