"Can I use this soil?" FAQ
Posted: Fri Jan 28, 2011 9:18 pm
Everyone seems to be posting guides recently, and I'm procrastinating at work, and I see the same soil questions all the time, so here goes!
*Disclaimer* If I'm wrong anywhere here, let me know and I'll change it
1. What is peat moss/Long fibered sphagnum moss?
Peat moss is partially degraded or composted Sphagnum moss. Long Fibered Sphagnum Moss is dead but undegraded moss.
2. What types of moss are ok to use for carnivorous plants?
As far as I know, ONLY sphagnum moss is ok as a growth medium for CP's. The moss can be composted (peat), "fresh" (long-fibered sphagnum), or live moss, but it has to be sphagnum. it's important to note that not all peat moss is sphagnum! Here's a quote from Steve:
3. Is coconut coir or "coco peat" ok to use?
Here's another quote from Steve from somewhere on the forum to answer this question:
The answer is, you want a ratio that's going to make it easy for you to keep track of the wetness and aeration of the soil. Aeration is important for good root growth and to prevent root rot. The moss contributes wetness to a soil mix by holding moisture in the soil, and the perlite/sand helps with aeration by allowing the formation of little air pockets. It's important to remember that in order for perlite to do its job the soil can't be overflowing with water.
The more perlite/sand you have in the mix, the less water the soil mix can hold, the faster it drys out, and the more air can get in. The more moss you add, the more water the mix can hold and the slower it drys out. But this also means less aeration.
Many growers like to saturate their soil, then let it dry out for a while before watering, so that air can get into the soil. This is basically alternating between high wetness and high aeration. Others just have their plants sitting in a tray of water. This is okay as long as you have a mix with plenty (at least 50%) sand and/or perlite. This allows air into the soil but constantly keeps the soil wet. I'm not sure either way is better, it's just a matter of balancing these two properties to keep your plants happy.
It's also important to remember that different plants prefer different levels of wetness, so do your research before deciding on a mix.
5. Can vermiculite substitute for perlite?
Perlite is mostly quartz(SiO2), which is insoluble and inert. This is why It's preferred over many other sands and soils, which contain soluble solids that raise the TDS in your pot. Vemiculite has a similar composition to that of perlite, but it appears there are two forms: an aluminous type, which contains no magnesium; and a silicious type, which does. Magnesium is very soluble, and over time the vermiculite may break down and leak this salt into your growing media. Without knowing more about the chemistry, I would recommend sticking with the tried and tested perlite. If you're sure you have pure aluminous vermiculite, or If you're willing to flush the water regularly, vermiculite should be ok. In that case though I wouldn't be comfortable unless I bought a TDS meter and made sure the TDS reading stays below 50.
6. What about other soil mixes? What else can I use?
As far as the "aeration" part of the soil goes, I've heard of people using smashed up styrofoam cups, plastic airsoft pellets, and other plastics. So long as the material is inert, it should work just fine. One thing to consider though is that perlite/vermiculite are very porous (lots of microscopic holes, like a tiny sponge). This is why they're so light, and probably why they're so good at aeration as well, because they provide a lot of surface area for evaporation and therefore dry out quick. You won't get that effect with styrofoam or plastic pellets. That being said though, if you're careful about watering you can use just peat moss, and there are growers that do this.
As far as the organic component of the media, I've read about people trying flytraps in medias like tea leaves, coffee grounds, and any number of other substances. I don't think I've ever read about any of these attempts being successful, which leads me to believe that they weren't. If you're going to try something like this though there are a couple important things to remember: The soil should be nutrient poor, low in dissolved solids, acidic, and should break down only very slowly. If you want to know about specific concentrations of specific nutrients and small molesules, you'll have to do your own research.
I'll add to this as I think of things, and if anyone would like to contribute, just reply!
*Disclaimer* If I'm wrong anywhere here, let me know and I'll change it
1. What is peat moss/Long fibered sphagnum moss?
Peat moss is partially degraded or composted Sphagnum moss. Long Fibered Sphagnum Moss is dead but undegraded moss.
2. What types of moss are ok to use for carnivorous plants?
As far as I know, ONLY sphagnum moss is ok as a growth medium for CP's. The moss can be composted (peat), "fresh" (long-fibered sphagnum), or live moss, but it has to be sphagnum. it's important to note that not all peat moss is sphagnum! Here's a quote from Steve:
Steve_D wrote: Not all peat is sphagnum peat moss, although most of the peat moss sold in the United States does happen to be sphagnum peat moss. But several plants, partially decomposed, are called "peat," including sedges (a grass-like plant that many people consider a problematic weed). So a bag labeled "100% peat" could possibly be 100% partially decomposed sedge rather than sphagnum moss. However, "peat moss" (with the word moss in the phrase) would probably (but not absolutely) be sphagnum peat moss.
One does need to be careful though, because manufacturers frequently label their products for marketing purposes (to sell the product) rather than for the convenience and assurance of the buyers.
3. Is coconut coir or "coco peat" ok to use?
Here's another quote from Steve from somewhere on the forum to answer this question:
Steve_D wrote:As Veronis mentioned, coir (coconut husk pith) is usually very high in soluble mineral salts that can easily damage or kill Venus Flytraps. The coir needs to be repeatedly soaked for 8-12 hours at a time, and drained between each soak, perhaps 10 or more times in total to bring the TDS (total dissolved solids) in the water drained from the coir down to below 50 ppm (parts per million).4. What's the correct ratio of moss/sand/other components?
I'm soaking some coir right now. The first water I drained from it, after soaking for over 8 hours, measured over 760 ppm, almost 4 times as mineral-laden as our very hard tap water here in eastern New Mexico.
Coir is a good ingredient for a growing medium and a good alternative to sphagnum peat moss, which is being harvested much faster than it can grow, while coconuts are a year-round tropical crop that is virtually endlessly renewable, since it uses the fruit and seed of the plant rather than the plant itself. However, coir really does need to be carefully treated and desalinated before use, as much of it is processed with very salty ocean water.
The answer is, you want a ratio that's going to make it easy for you to keep track of the wetness and aeration of the soil. Aeration is important for good root growth and to prevent root rot. The moss contributes wetness to a soil mix by holding moisture in the soil, and the perlite/sand helps with aeration by allowing the formation of little air pockets. It's important to remember that in order for perlite to do its job the soil can't be overflowing with water.
The more perlite/sand you have in the mix, the less water the soil mix can hold, the faster it drys out, and the more air can get in. The more moss you add, the more water the mix can hold and the slower it drys out. But this also means less aeration.
Many growers like to saturate their soil, then let it dry out for a while before watering, so that air can get into the soil. This is basically alternating between high wetness and high aeration. Others just have their plants sitting in a tray of water. This is okay as long as you have a mix with plenty (at least 50%) sand and/or perlite. This allows air into the soil but constantly keeps the soil wet. I'm not sure either way is better, it's just a matter of balancing these two properties to keep your plants happy.
It's also important to remember that different plants prefer different levels of wetness, so do your research before deciding on a mix.
5. Can vermiculite substitute for perlite?
Perlite is mostly quartz(SiO2), which is insoluble and inert. This is why It's preferred over many other sands and soils, which contain soluble solids that raise the TDS in your pot. Vemiculite has a similar composition to that of perlite, but it appears there are two forms: an aluminous type, which contains no magnesium; and a silicious type, which does. Magnesium is very soluble, and over time the vermiculite may break down and leak this salt into your growing media. Without knowing more about the chemistry, I would recommend sticking with the tried and tested perlite. If you're sure you have pure aluminous vermiculite, or If you're willing to flush the water regularly, vermiculite should be ok. In that case though I wouldn't be comfortable unless I bought a TDS meter and made sure the TDS reading stays below 50.
6. What about other soil mixes? What else can I use?
As far as the "aeration" part of the soil goes, I've heard of people using smashed up styrofoam cups, plastic airsoft pellets, and other plastics. So long as the material is inert, it should work just fine. One thing to consider though is that perlite/vermiculite are very porous (lots of microscopic holes, like a tiny sponge). This is why they're so light, and probably why they're so good at aeration as well, because they provide a lot of surface area for evaporation and therefore dry out quick. You won't get that effect with styrofoam or plastic pellets. That being said though, if you're careful about watering you can use just peat moss, and there are growers that do this.
As far as the organic component of the media, I've read about people trying flytraps in medias like tea leaves, coffee grounds, and any number of other substances. I don't think I've ever read about any of these attempts being successful, which leads me to believe that they weren't. If you're going to try something like this though there are a couple important things to remember: The soil should be nutrient poor, low in dissolved solids, acidic, and should break down only very slowly. If you want to know about specific concentrations of specific nutrients and small molesules, you'll have to do your own research.
I'll add to this as I think of things, and if anyone would like to contribute, just reply!