Peat Moss vs Sphagnum Moss as a Growing Medium

If you have been part of the carnivorous plant hobby for some time, the phrase "peat and perlite" likely has become as ubiquitous to you as something like cookies and milk or shoes and socks. This popular growing mix has been used mainly for temperate carnivorous plants for decades, and for good reason - its inexpensive, provides adequate drainage and moisture retention, and simulates the natural acidic and nutrient-poor growing environment of carnivorous plants. But if you can afford the upgrade, you should consider switching your growing medium to long-fibered sphagnum moss (LFSM), because it provides better drainage, increased growth rates, and is more sustainable.

What is Long - Fibered Sphagnum Moss?

Simply put, long-fibered sphagnum moss is peat moss before it has been broken down. In sphagnum bogs, sphagnum moss grows in long, fibrous strands upwards, with an active growth point at the top and dead moss at the bottom. As the dead moss gets buried and breaks down in the acidic environment, it compacts into peat moss, which is harvested and sold as a soil amendment or growing medium. Long-fibered sphagnum moss is just the moss that hasn't broken down yet and still takes the form of cohesive fibers. Like peat moss, it is dried and sold as a growing medium.

Cross - section showing the different layers of a Peat Bog. As plants and moss decay, they get buried and break down into peat (dark brown layer)

Growth Pattern of Sphagnum Moss. The top portion is the live growth; the bottom portion is the dead moss. This whole section of moss is typically harvested and sold as long-fibered sphagnum.

What makes LFSM better?

1. Light, Fluffy Texture

   Because LFSM comes in long, thick fibers, it resists compaction, since its fibrous nature does not allow it to fill in every small crevice as well as peat moss. As a result, it retains a lot of air pockets, even after heavy watering, which is crucial to root health and optimized growth. Peat moss tends to compact over time, even with perlite or sand added, which can lead to suffocated roots, especially in tropical pitcher plants, which have thin roots. LFSM is also a "squishier" medium than peat and perlite, which means that rhizomes and roots can swell up and dig in with less resistance. The plants in my collection that have the largest and healthiest root systems have all been grown in LFSM.

2. Fast, Consistent Drainage

   While peat and perlite provides ample drainage, it tends to lose this property when watered from above because the perlite will float to the top of the pot, leading to the lower layers of medium lacking perlite for drainage. Pure LFSM is not prone to this issue, since it does not compact and does not require additional drainage amendments to drain quickly. In fact, pure LFSM drains quicker than peat amended with perlite, since its structure creates larger air pockets than perlite does. LFSM's outstanding drainage also makes flushing media much, much less time consuming.

3. Longer Lasting

   LFSM holds its structure and is naturally less decomposed than peat moss, so it can be used for more than one season, especially if rinsed before consecutive uses.

4. Encourages Faster Growth, Especially in Small or Sick Plants

   I have noticed in my collection that small or sick Venus Flytraps exhibit almost instant increased growth rates once transferred from peat moss to LFSM. I believe this is due to a combination of substantially increased aeration, softer medium, and easier root penetration. Another interesting point is that when transferred to LFSM, they rarely show any signs of repotting stress, if any, and hold onto older leaves for longer.

   

   Baby GJ Goliath VFT in March 2025

   

   The same GJ Goliath in May 2025, after being switched to LFSM, still carrying its young leaves.

   
   
   
   

   

   Baby B52 and Maroon Monster in Peat and Perlite

   

   B52 and Maroon Monster 3 Months later, in LFSM

5. Allows for Growth of Live Sphagnum

   Live sphagnum moss is highly sought after for its vibrant, fluffy appearance as a top dressing. However, it needs a foundation of LFSM to grow on, and it does not grow well directly on peat moss. Thus, if you want to add more color to your collection, you should consider switching to LFSM.

   
   

   

   Venus Flytrap nestled in a pot of Live Sphagnum

   
   

6. Sustainability

   Live Sphagnum moss grows relatively quickly, and can be harvested and re-harvested ever "5-6 years"(What's the Difference Between Spagmoss and Peat Moss? The Environment - Besgrow - At the Root of Healthier Plants). Peat moss, on the other hand, can take centuries to form, as it must be deeply buried and broken down naturally before being harvested, making harvesting it a very unsustainable practice. Continued use of peat moss can lead to pollution, environmental damage, and habitat loss of the carnivorous plants we love so much.

What are the drawbacks to using LFSM?

Cost

Long - Fibered Sphagnum moss, by volume, is much more expensive than peat and perlite, especially if you decide to invest in high quality New Zealand Sphagnum moss. A 0.11 cubic foot brick of dried LFSM will typically run you $5-$6, while a 3 cubic foot bale of compressed peat moss will cost you $25, making peat moss many times cheaper. As such, Long Fibered Sphagnum moss is best used in small collections or for specimen plants.

Conclusion

Long - Fibered Sphagnum moss and Peat moss mixed with perlite are both great growing mediums for carnivorous plants. Long - Fibered Sphagnum usually will provide considerably better growing results and is more sustainable, however, it can be pricey, so it is best suited for small collections or for statement plants. Peat moss is unsustainably harvested and provides less in terms of drainage and plant growth but is better for large collections or those who are on a tighter budget because it is much cheaper. Both work well, but if possible, you should choose Long - Fibered Sphagnum Moss.