High-Density Polystyrene Insert for Window Box L - Pot 13/14 - 780x245x210mm

Cut from high-density foam to fill the inside of the window box completely. This is what holds an artificial arrangement upright in a trough.

What it does

A window box is long and shallow, so there's nothing for a plant to lean against and nothing to stop stems sliding together at one end. The foam fills the box from end to end. Stems push straight into it and stay exactly where you put them — upright, spaced the way you set them, and holding that spacing when the box is moved or carried.

What it fits

• Window Box L 80 × 26 × 26cm Sage — Pot 13
• Window Box L 80 × 26 × 26cm Coal Black — Pot 14

One insert per box, sold separately from the box itself.

What else you need

A topping to cover the foam once the arrangement is set — bark chip or moss, whichever finish you want. Bark chip is bought per box, two 1kg bags for this size. Moss goes further: one 500g pack covers several boxes.

Foam, not packing material

This is high-density foam, precision cut for one job. It isn't the loose polystyrene, rubble or offcuts sometimes pushed into the base of a planter, which shift under the plant and can't be reseated once they drop.