50-Cell Square Plug Flat Insert

The 50-Cell Square Plug Flat Insert is a propagation tray insert designed for starting seeds or rooting cuttings in coco plugs, standard potting soil, or soilless mixes. Each of the 50 square cells gives developing roots their own defined compartment, which makes transplanting cleaner and reduces root disturbance. The insert fits into heavy-duty Cut Kit Trays and all standard seed flats, so it works with trays most growers already stock.

50-Cell Square Plug Flat Insert Specifications

Specifications are derived from supplier documentation for SKU CK64005-1. This insert is sold as a single flat; case quantities are available under SKU CK64005.

Why Choose the 50-Cell Square Plug Flat Insert

The insert is built to work with media types that behave differently at the propagation stage. Coco plugs hold moisture longer than standard soil and benefit from a snug cell that keeps the plug upright and in contact with the tray floor. Soilless mixes tend to slump and settle unevenly in round cells; the square geometry of this insert helps the medium stay column-shaped so roots grow straight down rather than sideways along the cell wall.

Fifty cells per flat is a practical count for hobby and small-commercial growers who need enough starts to allow for normal attrition without wasting media or bench space. Each cell is sized to hold a usable plug or small cutting without being so large that the medium stays wet too long between watering cycles.

• Square cells reduce corner air-gaps that lead to dry spots in round-cell inserts.
• 50-cell count gives a full flat of starts while keeping individual cell volume reasonable for quick rooting.
• Fits heavy-duty Cut Kit Trays and standard seed flats, so no proprietary tray purchase is required.
• Works with three common propagation media types: coco plugs, potting soil, and soilless mixes.
• Single-flat SKU (CK64005-1) lets growers buy what they need without committing to case quantities.

Best Uses for the 50-Cell Square Plug Flat Insert

This insert is suited to any propagation workflow where the grower fills individual cells rather than broadcasting seed across a flat. It is most useful in the following situations:

• Vegetative cloning: Place one cutting per cell in a moistened coco plug or soilless medium. The individual cells prevent root cross-contamination between cuttings during the rooting phase.
• Seed starting: Direct-sow one or two seeds per cell in potting soil or a soilless seed-start mix. Thinning to one seedling per cell is straightforward because cells are clearly delineated.
• Plug transplant staging: Use the insert to hold pre-purchased coco plugs in an organized grid before transplanting into larger containers. If you are also using a 3-gallon fabric pot as your finishing container, the insert gives you a structured holding stage before the final transplant.
• Small-batch propagation: Growers who run 25–50 plants per cycle can fill one flat and track germination rates at the individual-cell level.
• Multi-media trials: Because the insert accepts coco plugs, soil, and soilless mixes interchangeably, it can be used to run side-by-side germination comparisons within a single flat.

For growers managing growing media in bulk, pairing this insert with a quality bagged medium such as Pro-Mix HP with Mycorrhizae gives a consistent soilless base for each cell.

Sources & Further Reading