Every spring, millions of gardeners use plastic plug trays to start seedlings. These black trays are common in nurseries, garden centers, and home greenhouses. Unfortunately, most of them end up in landfills. So, what should you do with these trays once your plants are in the ground?
Each year, the U.S. container crop industry produces about 4 billion plant units, which leads to around 500 million plastic pots, trays, and flats. This adds up to about 350 million pounds of plastic waste annually. Marie Chieppo, an ecological landscape designer and member of the Horticultural Research Institute’s Plastic Task Force, found that 95% to 98% of plastic plant containers end up in landfills instead of being recycled, even when gardeners put them in recycling bins.
Why You Can’t Recycle Garden Plug Trays in Curbside Bins
Garden plug trays are especially hard to recycle. Most are made from black plastic, like polystyrene or polypropylene, which can’t be identified by the sorting technology at most recycling centers. The dark color absorbs the scanner’s light, so these trays are sent to the landfill even if they have a recyclable code.
Plug trays are also usually dirty, with leftover soil, roots, and other organic material. Even if a recycling center could sort them, they would need to be cleaned first, which is not practical for most curbside programs. Different manufacturers use different types of plastic, making it even harder and less cost-effective to recycle these trays.
Don’t put garden plug trays in your curbside recycling bin. They can contaminate the recycling stream.
Recycling Options
Although you can’t recycle garden plastics through curbside programs, some specialized programs do accept them.
TerraCycle Garden Products Zero Waste Box: TerraCycle has a pre-paid mail-in Zero Waste Box for garden pots, trays, plant markers, and other garden plastics. Boxes start at $169, so it’s a good idea to organize a group collection with neighbors or your garden club to share the cost. If 10 people split a box, it’s less than $17 each, which is a small price to keep hundreds of trays out of the landfill.
East Jordan Plastics Closed-Loop Program: East Jordan Plastics in Michigan runs a recycling service for nurseries and garden shops. They collect used containers they’ve made and turn them into new trays and pots. Their products use recycled materials and have Post-Consumer Recycled (PCR) Plastic Certification. Some nurseries work with East Jordan to collect used containers during deliveries. Ask your local nursery if they take part in this program.
Nursery Take-Back Programs: Some garden centers and nurseries will take back used pots and trays for reuse or recycling. The Healthy Pots, Healthy Planet initiative, started by the Association of Professional Landscape Designers, has resources to help you find nurseries that participate. You can help by asking about recycling at your local garden center. If they don’t accept returns, your request shows there is demand for these programs.
Reuse Your Plug Trays in the Garden
The best way to reduce waste is to reuse your plug trays for as many seasons as you can. Here are some practical tips to help them last longer.
Clean and sanitize between seasons. Wash trays in warm, soapy water immediately after emptying them because dried soil is much harder to remove later. For sterilization to prevent the spread of pathogens or pests, soak the trays in a dilute bleach solution of one part bleach to nine parts water for 10 minutes, then rinse thoroughly. Community forum members at Dave’s Garden report that running trays through a dishwasher on a brief cycle also works well for small batches.
Share trays with other gardeners. Kris at Montana Homesteader points out that swapping trays through gardening groups and community gardens helps them last longer. Her homestead donates seedlings to food banks using collected trays, which is something any community garden can do. Look for local gardening groups on Facebook or Nextdoor to find people offering or looking for used trays.
Consider buying heavy-duty reusable trays. Companies like Bootstrap Farmer sell strong plug trays made from BPA-free polypropylene, and they come with a one-year warranty against breakage. These trays are built to last for many seasons. While they cost more upfront, the price per season goes down the longer you use them.
Creative Reuse Ideas Beyond the Garden
When your plug trays are too brittle for seedlings, their divided design can still be useful around the house or in the workshop.
Craft and art supply organizers. The small cells in a plug tray are just the right size for sorting beads, buttons, sequins, small screws, or nails. The Center for Environmental Health suggests using these trays to organize art supplies like crayons, markers, beads, and sewing notions. A 72-cell tray can quickly become a sorting station for diamond painting, jewelry-making, or any craft with tiny parts.
Paint palettes and mixing trays. Ecomasteryproject.com recommends cutting plastic containers into paint palettes, mixing trays, or stencils. Plug trays are great for watercolors or acrylics because each cell can hold a different color, and you can rinse and reuse the whole tray.
Classroom and kids’ activities. Tanya at Crafty For Home shows how cell trays can be used for kids’ seed-starting projects. The cells also work well for classroom sorting activities, color mixing, or holding small items for math lessons.
Hardware and workshop storage. Use old trays to sort and organize screws, nails, washers, and other small hardware in your garage or workshop. You can stack several trays in a drawer to make a simple parts organizer.
Seed saving and drying. The individual cells are perfect for drying and sorting seeds you collect at the end of the season. Label each cell with the variety name before storing them for winter.
Switch to Compostable Alternatives
The best long-term solution is to stop using disposable plastic trays altogether. There are now several good alternatives.
Soil blockers eliminate the need for any container at all. As the team at Apple Acres Farm explains, soil blockers compress potting mix into freestanding blocks that hold their shape as seedling roots develop. The roughly $75 investment in a soil blocker form can replace years of tray purchases, and after the growing season there’s nothing to clean, store, or dispose of.
CowPots are made from composted cow manure and recycled newsprint. They last about 12 weeks in a greenhouse, then break down in the soil within weeks after planting, adding nutrients as they decompose. Robin Sweetser at The Old Farmer’s Almanac calls them her “favorite eco-friendly container” because plants grown in CowPots often grow larger than those in plastic, thanks to the extra nutrients.
Other biodegradable options include pots made from wood fiber, coconut coir, rice hulls, and bamboo pulp. The Horticultural Research Institute’s Plastic Task Force is testing compostable alternatives for commercial use, and Marie Chieppo notes that bioplastic containers made from renewable materials are already “making a significant dent” in the market.
DIY newspaper pots are a free option that gardening blogger Tanya at Lovely Greens recommends for home gardeners. Just roll strips of newspaper around a can or jar, fold the bottom closed, fill with soil, and plant the whole pot when your seedlings are ready. The paper breaks down in the soil within weeks.
Take the Plastic Out of Your Garden
We may not solve the garden plastics problem right away, but small actions can make a big difference in reducing plastic waste from gardening:
- Reuse your existing trays as long as they hold together.
- Find creative second lives for used trays rather than tossing them in the trash.
- Pool resources with neighbors for a TerraCycle box.
- Ask your nursery if they take back containers — and tell them it matters to you.
- When you need new trays, think about buying durable reusable ones or switching to compostable options.
The key to change is talking with your neighbors during planting season. Take a few moChange starts with talking to your neighbors during planting season. Take a moment to ask how they start or buy their seedlings and share a few ideas to help them reduce waste. Good gardening habits spread through simple conversations.