Park Seed 60-Pack Bio Sponges for 60-Cell Planting Block — Pre-Drilled Seed Pockets, Oilseed Extract

Park Seed 60-pack Bio Sponges are replacement growing plugs sized to fit the original 60-cell planting block, giving you a quick, hygienic way to start a new tray of seedlings.

These refill sponges restore your planting block to ready-to-sow condition: they expand after a short soak, reveal a pre-formed seed pocket, and slide into each cell so you can plant uniformly and efficiently. The sponges are now formulated with an oilseed extract to support early root and shoot development, and they’re inexpensive to stock up on so you can reuse your planting block season after season.

How do I prepare and use the Bio Sponges?

Preparing the sponges is simple and fast. Sanitize the planting block, soak the sponges briefly in warm water so they swell, pop a seed into each pre-drilled pocket, and set them into the block seed-side-up.

• Sanitize block with warm water and a splash of household bleach, then rinse thoroughly.
• Soak sponges for a few minutes until fully expanded and soft.
• Place one seed in each pre-formed hole, then insert sponge into each cell.
• Keep tray level and maintain moisture for consistent germination.

What benefits do these sponges offer over soil or loose media?

Bio Sponges deliver uniform spacing, cleaner handling, and less mess than loose potting mixes. Their consistent shape and seed pocket mean each seed sits at the same depth for more predictable emergence.

• Pre-drilled holes ensure uniform seeding depth and spacing.
• Reduced transplant shock when moved from cell to pot or garden.
• Cleaner setup and easier cleanup compared with soil-filled trays.
• Oilseed extract added to support early seedling vigor.

Will these sponges fit my planting system and how many do I get?

These refills are specifically sized for the original 60-cell Park Seed planting block and come as a 60-count pack so you can replace every cell at once. Park Seed also offers different sponge sizes for their other dome models, sold separately.

• Pack contains 60 individual sponges for the 60-cell block.
• Compatible with Park Seed Original 60-Cell Planting Block.
• Other sizes available for Jumbo 40-Cell and Whopper 18-Cell domes.
• Each sponge expands when soaked for an easy fit inside cells.

How do I get the best germination results with these sponges?

Success depends on seed quality, consistent moisture, light, and temperature. Keep sponges evenly moist (not waterlogged), provide appropriate heat and light for the species you’re starting, and transplant seedlings when roots begin to show or when true leaves develop.

• Maintain even moisture without drowning the sponge plugs.
• Provide supplemental heat or grow lights for faster, uniform sprouts.
• Transplant when seedlings are robust with developed roots or true leaves.
• Follow seed-specific instructions for depth and light requirements.

Who is this for? Home gardeners, educators, and small-scale growers who already own the Park Seed 60-cell planting block will find these sponges a practical, cost-effective way to restart trays quickly. They’re ideal for anyone who wants tidy, uniform seed starts without the mess of loose media, and for growers who prefer lightweight, easy-to-handle plugs for classroom projects, greenhouse flats, or frequent succession planting.