Comparing Biodegradable Plant Pots
Comparing Biodegradable Plant Pots
The Breakdown on Biodegradable Pots
In an effort to reduce my plastic usage, I have shifted my focus from traditional plastic pots to biodegradable options for starting seeds and nurturing young plants. The challenge was to evaluate how these biodegradable pots measure up against their plastic counterparts—not just in terms of ease of use but also their impact on growth and decomposition within a single growing season.
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Exploring Various Biodegradable Pot Types
For my informal experiment, I decided to plant Xochi Orange marigolds (Tagetes hybrid) in eight different types of biodegradable pots. All seedlings were started indoors using the same potting mix, lighting, watering, and fertilizing routines over nearly 10 weeks, which turned out to be longer than intended due to poor weather for transplanting. Interestingly, the seedlings exhibited noticeable differences in growth patterns while indoors, as reflected in a photo I took before transplanting. However, once I moved them outdoors—pots included—into a raised garden bed, the marigolds began to grow uniformly within a couple of weeks, making it difficult to discern any differences among the various pot types.
End-of-Season Observations
When the season ended and temperatures dropped, I dug up the plants to assess the pots. While I noticed some roots slightly obstructed by pot materials, with roots either growing over the top or through drainage holes, all plants thrived remarkably well. Upon inspection, remnants of the pots were still identifiable, with most crumbling easily into the garden soil, while a few would benefit from an extra season in the compost bin for complete breakdown. In any case, the advantage of not having to store pots was a welcomed perk! Discover my detailed findings in this section.
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Pros & Cons of Different Biodegradable Materials
Peat or Fiber Pot StripsMolded multi-packs made of peat or wood fiber
- Easy to fill and plant; compatible with standard-sized flats and trays.
- Retained shape when wet and soft; simple to separate cells; the entire pot can be buried to maintain moisture levels.
- End-of-season, mostly intact yet decayed; easily found and quite affordable; available in various sizes; peat pots tend to break down faster than their fiber counterparts.
Compressed peat or coir with mesh covering, expands when wet
- Simple to soak in leak-proof trays; mesh creates issues during seed planting; no extra mix is required to cover seeds.
- Roots penetrated the mesh, growing through the bottom and tangling easily, making it easy to tease apart for planting.
- End-of-season, mesh still intact while the coir or peat core formed; no choice in potting mix; leak-proof tray lacks drainage, making overwatering a concern.
Cardboard tubes from toilet paper or paper towel rolls
- Crafted easily and filled well; pots did not always sit evenly.
- Quickly dried out but prone to mold when overwatered; roots found it harder to penetrate compared to other materials.
- End-of-season, the material remained intact and easily tore apart when damp; virtually free; more time required for preparation; the cardboard sometimes unraveled at the top.
Molded peat round pots
- Convenient to fill with potting mix; compatible with various trays.
- Moist peat helped roots grow through; if it dried, it hardened and limited root growth; exposure above ground could wick moisture away.
- End-of-season, peat was still visible yet deteriorated; reasonably priced and widely available; easily crumbled to enrich the soil.
Rolled newspaper or grocery bag strips with crimped bottoms
- Simple to create but slow; difficult to fill due to crushable paper.
- Quickly dried when neglected; mushy state made handling tricky.
- End-of-season, remaining bits of paper were minimal; a great way to recycle; can form pots using a drinking glass or a special tool.
Nonwoven biodegradable fabric bags
- Hard to fill, as the flimsiness made it unstable; prone to tipping over.
- Roots penetrated easily through the bag, complicating removal during planting.
- Material stayed intact after one growing season; inexpensive, can ship flat, and can be written on; light is necessary for breakdown or could take multiple seasons to decompose.
Sturdy paperboard boxes designed with a matching tray for support
- Boxes popped open effortlessly; sturdy enough for filling with soil; easy to add seeds and cover.
- Softened yet still handled well for transplanting; roots found it challenging to grow through cardboard, though perforated bottoms tear off easily for root growth.
- End-of-season, boxes remained intact but began to crumble; packed flat to minimize waste; a labeling opportunity exists on the box.
Lightweight paper cells stacked like an accordion
- Need a specifically-sized perforated flat and tool to secure the accordion until filled; simple to plant.
- Easy to move as a unit but less effective when separating each cell; moisture weakened paper, and tearing occurred while transplanting; roots grew out from the bottomless cells, tangling.
- End-of-season, partially intact but deteriorated; the initial investment for the specialized flat and separating tool is pricey, yet affordable accordion refills ship flat; challenges exist for partial planting.
Key Insights from My Biodegradable Pot Experiment
After conducting this experiment, which biodegradable pot did I deem the best? Interestingly, there was no clear standout that consistently performed better across the board. Each pot has its unique situations that suit particular purposes, and I plan on utilizing them all again. Here are a few key insights:
For Large-Scale Planting: The peat or fiber pot strips as well as honeycomb paper flats were optimal for cultivating large quantities of identical plants due to their efficiency in space usage, allowing for close watering access.
Versatile Expandable Pellets: If these are available without the mesh covering (like what I found from Gardener’s Supply), they decompose entirely into organic matter within the garden. Though, if they do have mesh remnants, they were easy to remove by the end of the season and toss in a compost bin.
For Recycling Enthusiasts: Toilet paper rolls and DIY newspaper pots are excellent for reusing waste that would typically be discarded, breaking down well and utilizing junk mail or grocery bags for when you need just a few pots.
Concerning Peat Pot Sustainability: While peat pots are hard to surpass in performance, concerns exist over their supply and sourcing. Thankfully, options like wood fiber pots, animal manure pots ("cow pots"), or coconut coir pots can serve as effective substitutes.
For Longer-Term Growth: I found fabric pots to be my least favorite in terms of usability. They were tough to fill and required support to stand up properly, but they developed strong roots for larger plants needing ample space, such as woody shrub cuttings. Their longevity could be advantageous for permanent plantings.
Minimizing Shipping Waste and Storage Needs: I appreciated how fabric pots, recycled paper boxes, and honeycomb flats arrive folded flat and come with minimal packaging. This detail makes them easy to store without cluttering with varied pot sizes for the following year.
Where to Find Biodegradable Pots
Peat or Fiber Pot Strips
- Local Garden Centers
- gardeners.com
- johnnyseeds.com
Peat or Coir Expandable Pellets
- Local garden centers
- gardeners.com
Peat Pots
- johnnyseeds.com
- Local garden centers
Fabric Pots
- Amazon.com
Recycled Paper Boxes
- botanicalinterests.com