INTRODUCTION: The goal of this project is to create an improved potting medium for organic vegetable transplant production. Healthy vigorous transplants will be less susceptible to insects, diseases and transplant shock leading to better crop performance. Formulating organic potting mixes is especially challenging. Composts are a popular organic source of nitrogen, but can have inconsistent nutrient levels based on their starting materials and poor physical characteristics (large particle size, etc.). Individual batches of compost can change over time with storage and N release can be unpredictable. An alternative to traditional composts is vermicompost. Vermicompost has a finely granulated texture, which is ideal for mixing into peat-based media or applying as a top dressing through existing greenhouse equipment. Past research in the Rangarajan lab has shown improved yield with vermicompost compared to thermophilic compost, even when the same starting material was used for both types of compost.