Plastic plant pots and seed starter molds are being shunned more and more in favor of alternatives that are kinder to the plants as well as the planet — and a popular planter that seems to fit this description is the peat pot.
What are peat pots? Peat pots are biodegradable plant pots made from sphagnum peat moss, wood pulp, and other fibrous material that are then compressed into the shape of individual nursery pots. These are designed to be planted in soil with seedlings and decompose over time.
You can start your garden in peat pots indoors and keep them in their biodegradable homes until it’s time to plant them outside!
However, they may not be for every gardener, so let’s find out more about using them, the typical sizes, decomposition time, starting seeds in them, and much more…
What Are Peat Pots Made Of?
Peat pots are made from sphagnum peat (the decayed remains of sphagnum moss), which becomes a fibrous, moisture-retentive material as it breaks down.
Due to this slow process, many manufacturers use coconut coir (coconut husk fibers) instead.
Then, either peat moss or coco coir is combined with shredded wood pulp before being compressed into the thickness and shape of a biodegradable plant pot.
What Are Peat Pots Used For?
Peat pots are commonly used as starter pots for growing seedlings with delicate roots that may then be transplanted into the ground or in larger containers once they mature.
They are a means of planting sustainably since the roots within peat pot seedlings typically stay within the pot, meaning nearby soil resources are not depleted.
Even unused or ripped peat pots can have their uses, as Adriana Sim of Tiny Garden Habit advocates using “leftover pots to mulch your garden to improve the soil quality!”
Peat Pot Sizes
Peat pot sizes range from miniature 3×3-inch round pots or 2×2-inch square Jiffy pots for starting seedlings all the way up to 12- and 13-inch pots (roughly 5 gallons) that can accommodate small shrubs and tree saplings.
However, the larger peat pots are normally constructed with tougher fibers and pulps rather than true peat moss.
What Size Peat Pot Do I Need?
Pots between 3 and 4 inches are perfect for starting most flower, herb, or vegetable seedlings.
Four-inch diameter pots are often best if you’re sowing larger seeds and large plants such as peppers and tomatoes.
I personally use and recommend these square 3-inch pots as they’re easy to group together on a tray and come at a bargain price.
Do Peat Pots Decompose?
Yes, as peat pots are made from biodegradable materials, they’re designed to gradually decompose and dissolve into the soil over time.
How Long Do Peat Pots Take To Decompose?
Generally, peat pots can take a year to break down fully in the soil, though some gardeners find that pots have yet to fully degrade more than a year after planting.
The quicker they break down, the more likely it is they are made from 100% biodegradable materials (or at least a higher ratio of them) like recycled paper, wood pulp, etc. that breaks down within months or even weeks.
The main substance (sphagnum peat) can take several years to decompose.
Do Plants Need To Be Removed From Peat Pots?
No, it is generally not recommended to remove plants growing in peat pots.
Peat pots are designed to grow plants with tender roots, so removing them from the pot not only risks damaging the fragile roots, but it also defeats the purpose of planting in a biodegradable pot.
Peat Pots Pros and Cons
Planting in peat pots is thought to be a sustainable practice that’s kind to your plant, but this method can have its downsides for many gardeners too.
Peat Pot Advantages
- Reduces transplant shock since the plant can simply be buried with the pot when the time comes, protecting the root system.
- Many can decompose within one growing season.
- Excellent moisture retention — the sphagnum peat element is known to hold up to 8 times its own weight in water, providing your plants with slow-release hydration.
Drawbacks of Using Peat Pots
- Depending on the size, thickness, and material composition of the pots, they may take a year or more to fully break down or break down far too quickly.
- Its high moisture retention is a double-edged sword as it can increase the risk of root rot and even be a haven for mold growth when seed-starting indoors.
- Some have very small drainage holes or none at all.
- Peat isn’t a renewable resource, so gardeners can’t rely on peat pots in the long term.
Starting Seeds in Peat Pots: How-To Guide
Peat pots offer an easy and gentle way to start growing seeds, particularly those with tender root systems. Let’s look at the process step by step:
- Fill each pot with some seed starter mix (I use this one) or, as the home gardening guru over at Little Home Projects recommends, “use 50/50 mix of potting soil and seed starter mix as this gives you the best bang for buck for seeds to grow well and not have to fertilize as you go.”
- Place the pots together on a 2-3 inch-deep seed tray or large baking pan. Depending on the seed size, you can make 2 or 3 planting divots in the soil mix of each pot, using the eraser end of a pencil or your forefinger.
- Sprinkle seeds into the holes made as per the sowing instructions on the seed packet, and be sure to place some seed label tags in each pot to identify them later!
- Next, fill a pitcher with lukewarm water, and pour it directly into the tray (not the pots) until there is around 1 cm of water sitting in the tray.
- After an hour or so, the pots should have fully soaked up the tray water. Repeat the process if the pots are still not moist. Keep the tray in a warm, sunny spot or place them under grow lights (grow five trays at once with this adjustable lamp), and they should sprout after roughly 2 weeks!
How To Water Seedlings in Peat Pots
Seedlings in peat pots need to stay moist but not soggy, so the easiest, most consistent method is bottom watering as often as necessary.
Add a centimeter or so of water to the tray you keep the pots in; the pots should absorb this within hours and remain moist for days.
You can help them retain extra moisture by taking measures such as:
- Using a plant mister directly on the seedlings twice daily.
- Resting the tray on a heated seed mat
- Pouring a small amount in each pot (if it soaks it up fairly quickly, you’ll know you’ve used just the right amount).
- Keeping a humidifier near the tray of seedlings.
- Covering them in a plastic humidity dome (most seed trays come with one anyway).
Do Peat Pots Need Drainage Holes?
Drainage holes are not necessary in peat pots when starting seeds as it’s important for them to stay moist at this early germination stage.
The lack of holes in peat pots can become an issue when they are transplanted into soil as not all plants have strong enough roots to push through the thick pot walls, which is why some gardeners make cuts/slits in the pot to enable root development.
As peat pots are expected to disintegrate within months, however, this step shouldn’t be necessary in most cases.
Transplanting Peat Pots
- Once seedlings are at least 3 inches tall, you can transplant them directly into the garden or their own container. First, ensure the weather/outdoor temperatures are suitable for the plant you’re growing.
- Help them transition to the outdoor elements by hardening them off first. This involves placing the peat pots in containers and keeping them outside for a few hours each day, increasing the time spent outdoors over 2 weeks.
- Before planting the pots in their permanent site, it helps to gently loosen the base of the pot to help fragile roots grow through and speed up decomposition. You can either soak the pot first and carefully crumble the base of the pot by hand or make shallow slits in the sides using a sharp knife.
- In your garden, dig a hole a little larger than the peat pot size and deep enough for it to sit in, amending the planting hole with the appropriate soil for your seedling (sandy, rich, loamy etc.).
- Bury the pot in the planting hole, making sure that no part of the pot is exposed above the soil as this will dry out and act as a wick, pulling moisture away from the roots, so be sure to tear off any exposed top portion of the pot.
- Thoroughly water your newly planted seedling straight away, and maintain a watering schedule in line with your plant’s specific irrigation needs.
Peat Pot Mold
Green, white, or bluish-colored mold can appear on the soil surface or on the sides and bottom of peat pots when the plants have been overwatered or if the pots are kept in an area with poor air circulation.
How To Get Rid of Mold on Peat Pots
Dump out the moldy soil from the pot, and if there is any mold on the peat pot itself, wait for it to dry before using a blunt knife to carefully scrape it off.
To prevent your peat pots from harboring mold in the future, take care to let the pots dry out a little between watering.
Also, ensure the pots are being kept in a room with adequate ventilation; place a fan in the room to get some air circulating, and spread the pots a little further apart in the tray to increase airflow.
DIY Peat Pots
You can quite easily make your own peat pots by using an empty juice container, a screwdriver and drill bits, wooden dowels, and peat moss to make a mold (instructions here), or use a similar principle using pudding cups and cardboard cuttings to make paper mache pots that will decompose much faster as demonstrated below.
Peat Pot Alternatives
As long as it is made from biodegradable material, you can fashion alternative peat pots from many household items like…
- Egg cartons (or eggshells!)
- Toilet paper rolls
- Cardboard rolls
Cardboard rolls are a popular homemade choice – simply make four cuts evenly spaced near the rim, creating flaps you can then fold in on themselves to form a pot shape!
Peat Pot Crafts
If you have a ton of leftover peat pots after the growing season and decide they’re not for you, you can still put them to fun use in many craft projects!
Pots can be painted and turned into cute Easter-themed baskets; decorated Halloween trick-or-treat buckets; cut-out lanterns for faux tea lights; gift bags containing candles, soaps, or sweet treats; or as cute planters/favors on wedding tables!
Peat pots provide a super simple and gentle way to start seedlings with delicate root systems and the draw of these bio pots is that your plants won’t suffer transplant shock once they move to the garden as the pot goes with them!
As convenient and versatile as peat pots are in many ways, the lengthy decomposition can be off-putting, so you may want to consider removing the base before transplanting so that fragile roots won’t be hindered, or look to alternatives made of similar materials that break down faster in the soil.