Jiffy's 50 cell 1.65' peat pellet seed starting greenhouse is a great way to get your plants going. Start up to 50 plants in this greenhouse tray and as a bonus get your seedlings off to a strong start with help from the sample of Super Thrive, a kelp-based vitamin for plants, that comes with this greenhouse. Just add water, pellet expands to form a pot and soil in one. Grows over seven times its compressed height after only a few minutes of soaking in water. Fine netting holds in the peat while allowing for air circulation and root growth. Our high-quality peat is compressed to form a less-mess pellet for indoor gardening and seed starting.