FlytrapCare Carnivorous Plant Forums

Peat vs. Long-fiber sphagnum

At times, this subject has been a point of much discussion in the flytrap community. For a long time I was convinced that long-fiber sphagnum was not a suitable growing medium for flytraps, or at least it wasn't ideal and that it was inferior to peat-based mixes. This belief was primarily supported not by my own experiences, but by what I'd read and heard from other expert growers who I respected and took their word as truth, almost unquestionable truth (though I pretty much question everything).

However, I was challenged by Joel, of Joel's Carnivorous Plants, a couple of years ago to test out the New Zealand long-fiber sphagnum he was using. In the preliminary test, I took 10 genetically identical plants and put 5 in our FlytrapStore Growing Medium, also known as a peat-based mix with silica sand and perlite, and the other 5 in the Premium New Zealand Long Fiber Sphagnum Moss, also known as NZ LFS or just LFS. The test was started in early May 2012. I was planning on taking a very scientific approach to it all, creating all sorts of metrics. I weighed each of the plants before the experiment started. At the end I had planned on weighing each of them again and measuring average root length among other things to determine the average weight and size increase of the plants. Turns out these metrics weren't necessary, at least not for my purposes (would be necessary to convince some people, I realize). By October 2012, just a few months later, the results were obvious with a simple visual inspection. The plants in the LFS were 2 or 3 times the size of the plants in the peat! There is a small possibility that the peat used wasn't rinsed well enough (peat should always be rinsed or at least checked for TDS levels before using it) and that there was a significantly high amount of total dissolved solids that stunted the growth of the plants in the peat-based mix. But this certainly wouldn't account for all of the drastic difference in size of the plants. And I've since done the same experiment several times and the results are always the same:

Flytraps grow faster in the LFS than they do in the peat-based mixes (at least with how I care for them in our environment).

Now, that isn't to say that the NZ LFS doesn't have its own quirks and drawbacks. As I remember them, I might augment these lists with other positives and negatives of using peat or LFS, but below is a list of my observations and the pluses and minuses of each soil mix.

Pluses of New Zealand Sphagnum Moss

• Flytraps grow much, much, much faster in the LFS compared to the peat-based mix. This cannot be understated. I hesitate to put a number as to how much faster exactly, because I didn't do any rigorous scientific measurements, and I'm sure it will vary depending on climate and other environmental conditions such as a plethora of bugs (we have essentially no bugs here in southern Oregon), but I would venture to guess in the matter of 3 or 4 months, small plants in LFS will have grown 2 or 3 times as large as similar sized plants potted in peat.
• Flytraps recover much faster after being repotted, losing fewer leaves and resuming growth more quickly.

Minuses of New Zealand Sphagnum Moss

• It is expensive.
• Keeping the moisture level correct is much more work because it requires more water and more frequent watering. Some people have found success leaving flytraps standing in water, but we try to avoid this at all costs as the plants are much more likely to rot and will not grow as well.
• Repotting is a huge pain because it's nearly impossible to separate the roots from the LFS without damaging them. Doing so properly takes an inordinate amount of time.
• Potting and repotting is much more time consuming.
• It seems to break down fairly quickly, requiring plants to be repotted at least once every 15-20 months. Peat-based mixes can sometimes last 2 years before the plants start to slow down in growth.
• It is light and pots can easily be tipped over unless something is added to the bottom to give them weight or the pots are made more stable in some other way.
• Grasses tend to grow in the LFS and they must be pulled out regularly to avoid later problems.
• Improper watering can more quickly lead to plant rot and death. I had lost very few plants using peat-based mixes. Since switching to the LFS, I've lost more.

Pluses of Peat-based mixes (peat/silica sand/perlite)

• It is relatively inexpensive.
• It is far easier to work with -- potting and repotting is a breeze and extremely quick.
• Maintaining a proper moisture level is far easier to do.
• Because it's easier to use and maintain, it's a better choice for someone new to the hobby or inexperienced with growing plants.
• It can last for 2+ years and the plants can grow well in it for all that time without being repotted (though this isn't guaranteed -- sometimes plants need to be repotted after just a year).

Minuses of Peat-based mixes (peat/silica sand/perlite)

• Peat requires a period of soaking prior to use to ensure low enough TDS.
• Plants grow much more slowly in it as compared to the LFS.
• Carpet moss can be very problematic.

In terms of the overall health of the plants once they reach an adult size, I'd say that the two medias (LFS vs peat-based mixes) are almost equivalent. I'd give a slight edge to the LFS because my plants looked slightly better this year than they ever have and grew extremely well in the larger pots. My preferred method for using the LFS with the large pots is to put a layer of peat/sand/perlite mix in the bottom to give it weight and prevent it from so easily being tipped over. The layer I put in was about 5 or 6 inches deep in a 12 inch pot. Then I wrap each of the plants in the LFS individually and add them to the pot on the top 6 inches.

Here are some photos of my mother pots from April 2014:
Matt's plants in April 2014

Some of the plants in the photos I had never ever seen that large before. This spring I was blown away by the size attained by several varieties growing in the LFS that I had been growing for over 5 years in peat and thought I knew how large they got. One example is FTS Crimson Sawtooth:



Roots in LFS compared to Peat-based mixes
I've heard some people claim that plants in the LFS don't develop as elaborate of root systems, but I didn't find this to be true. If the soil moisture level is maintained at a proper level, the root systems can get quite elaborate and just as elaborate as flytraps grown in peat-based mixes. See the below photos of my Low Giant mother pot when I repotted it on August 28, 2014, after it had been potted in the NZ LFS in March of 2013.

Long roots coming out of the LFS and into the bottom-layer of peat/sand/perlite:


Just a few of the plants in the pot when stripped of LFS:


The same pot in April 2014:


Bottom Line:
The number of minuses of the LFS is larger than the pluses for it and shorter than the minuses for the peat-based mix. Additionally, the pluses of the peat-based mix are more numerous than the pluses of the LFS. However, for us the choice is simple. We want our plants to get large as quickly as possible and to be as healthy as they possibly can be. LFS allows us a better way to do this than the peat-based mixes. Thus, we choose to primarily use LFS for all of our potting needs, sacrificing time during potting/repotting and watering. The additional labor is annoying, but the payoff is worth it for us.

There are some exceptions as certain varieties of flytraps seem to struggle in the LFS or just grow better in the peat-based mixes, at least with how I'm caring for them. But the vast majority (99%) of our flytraps grow much faster, healthier and stronger in the LFS.

LFS it is for FlytrapStore!

What soil/medium do you prefer and why?

I like the lfs for VFTs. I can never keep vfts happy in peat mixes. The plants in lfs I just top water once or twice a day and theyre thriving. When I can afford it all of my vft are going in lfs.

I was keeping my plants in a peat-based mix because its more of a "traditional" soil, and I used it for other plants too. I never felt like making a switch to LFS until they started to go downhill in health. I've only had my VFTs in LFS for a few weeks, and the LFS seems better so far. It seems to be preventing rot, and mixed with perlite its very "airy" and does not compact. About two weeks after repotting new healthy growth is starting to appear.

I've personally had trouble growing in 100% LFS; moisture level was an issue for me. I've wavered around with several medium mixes. I've also decided that I don't like sand in the medium, and I went from 50/50 peat/perlite to "Man, I hate all these dried white rocks on the surface!" And, yes, LFS is waaaaaaaaaaaaay more expensive than peat.
This past year, I've tried to have the best of both worlds: I go with about 50% peat, 30% LFS, and 20% perlite.
Seems to be working out pretty good for me. I also tend to tear the LFS up a little bit when mixing. With seeds/leaf pullings/very small divisions, I go a little heavier on the LFS.
As with most convictions related to CP growing, we stand on the shoulders of giants Like Matt and Steve, and Joel, and Eric, and are very grateful for the knowledge bestowed.
As far as rinsing the peat, I haven't yet figured out a reasonable method for doing so; I picture pouring a gigantic pot of boiling water onto a gigantic screen or colander filled with a couple cubic feet of peat. Not sure where to acquire such equipment, and smaller scale methods that I can imagine seem impractical. So I'll just take my chances with "Dirty Peat" for now.

I agree with you 100% and have stated this numerous times throughout posts here on the forum, even as far as the potting and repotting.

Good write up!!

sbrooks wrote:As far as rinsing the peat, I haven't yet figured out a reasonable method for doing so;

It's really a pain. We have a huge plastic bin in which we've drilled dozens of small holes in the bottom. We fill it up with peat and the saturate it until the container is completely full of water and let it slowly drain. We refill, take some of the water off the top and measure the TDS. If it's above 50ppm, we'll do it again and again until we get it below 50ppm.

Matt wrote: We have a huge plastic bin in which we've drilled dozens of small holes in the bottom. We fill it up with peat and the saturate it until the container is completely full of water and let it slowly drain. We refill, take some of the water off the top and measure the TDS. If it's above 50ppm, we'll do it again and again until we get it below 50ppm.

Excellent! Thanks, Matt!

My experience is I use both medias. My technique is I use LFSM and wrap the roots with it vertically. When that is covered with at least half an inch all around, I position it in the pot and use the flytrapstore peat mix and dump it around.

I then put a layer of LFSM on the top, with live sphagnum as the final top dressing.

My logic for doing all this is as follows: The LFSM wrapping helps keep the roots wet and prevent fungus/mold. The peat surrounding keeps the pot just wet and loose enough where extra water flows down. The LFSM/live sphagnum at the top is to prevent anything from growing on the top layer, and it's a good indicator of when to water; basically I spray it twice a day and it keeps the whole pot consistently wet enough without having to actually pour water.

I use all lfs, and love it. Withe mine being in one giant pot, I find I don't struggle with the watering issue, either. With the pot being a reservoir pot, even when rain fills the 2" reservoir, (18" tall pot!), the water level is never high enough to cause root rot issues, but does keep it overall moist enough to go a week between waterings, in 90 degree heat, near 90-100% humidity. I have a much smaller pot that I have seedlings in, and struggle with however, because of the tiny root systems. So I think that, unless you're using a larger pot for a lot of seeds, lfs may not be the best for seed germination, or is at least more difficult to keep adequately hydrated for seeds once you remove a humidity dome.


Sent from my iPhone using Tapatalk

I have noticed very similar pros/cons between the two mixes, and I'm about to switch completely to LFS this weekend. I have had a few water logging issues with the standard 50/50 mix as this summer has had some very rainy periods. However, my plants in LFS (I use both NZ LFS on FTS potted plants and Chilean LFS on others) seem not to be as affected by prolonged rain. I have had some algae growth on the top layer but no other noticeable setbacks as compared to the root rot I've experienced with 50/50. In addition, I have noticed much faster growth in LFS vs. 50/50.

bannister, I do the same thing... It works well for me.

Sent from my KFTHWI using Tapatalk

Great comparison matt, this was much needed from someone with as much experiences as yourself! We are moving forward with media in terms of VFT's. I remember when i first started making sure the bulk of my collection was in the "standard mix", because all my research on LFSM was very uncertain. I have seen the differences and convinced LFSM is the superior media only if the right criteria are met by the grower. In larger pots I see it as the preferred media to achieve larger plants even without the tray method. Although more expensive, one can buy in bulk and find excuses to use it (more VFT's, nepthenes, sarrs, orchids).

Nice article! 0

Wonderful post Matt! Completely agree. My plants have done spectacular in it. Idk about everyone else here but I like to use better gro orchid lfs. $5 a brick at lowes seems pretty reasonable. Well, for a few plants at least. Maybe not for a large operation.


Sent from my iPod touch using Tapatalk

Hey Matt, is there any reason why you put a small layer of peat on the bottom (referring to the low giant pic)?