The cells of this reusable polystyrene seed starter kit are hinged at the bottom to open like a book so you can inspect the root growth at any time or remove the plant for transplanting. Roots are automatically air-pruned to create a denser root mass, and grooved sidewalls direct them straight down to minimize spiralling.

Seedlings slide out easily, avoiding damage to the root system and associated transplant shock. Similar to seed starters used in commercial nurseries. Cells are 5" deep by 1 1/2" square.

Each kit is made up of one 14 1/4" x 8 1/4" frame (requiring minor assembly) and eight four-cell books (for a total of 32 growing cells). Instructions included.

The grooved growing cells train roots down and out from the plant, preventing spiraling. And you can detach one wall and check the progress of your plants' growth!

For big, healthy, well-rooted plants from seed or cuttings, look no further than Rootrainers®! And it's so much fun – with this rooting system, you can actually watch the progress of your plants anytime you want just by opening one side of the 4-celled unit! If you grow much of your garden from seed or cuttings, or grow large seed that do not fit in small-plug seed starting units, this is the tray you want!

Each cell of this 32-cell tray is 1 1/2 inches square and 5 inches deep – that's enough room to let you really get started on a substantial root system before transplanting into the garden or container! Just fill each cell with your choice of potting medium, water in, plant your seed or rooted cutting, and wait. The cells of Rootrainers® are grooved, encouraging roots to grow straight down and away from the plant instead of spiraling around. This makes for easier transplant and much larger, better-branched root systems!

When your plants are ready for transplant, you will see their roots "trained" along the outside of the cell and dangling free at the bottom, just waiting to take off in your garden or container! Endlessly reusable, these trays will save you time and money as you grow larger, healthier plants, with fewer losses from strangled roots, premature transplant, and other pitfalls of traditional indoor seed-starting kits.