Sphagnum moss can be expensive, particularly if you opt for a high-quality variety. Given the expense, it’s natural to wonder if you can reuse sphagnum moss.
There are some situations where reusing the moss is fine. However, there are some caveats, and a process to follow when doing so.
Types of Sphagnum Moss
When deciding whether or not to reuse moss, you should consider its type. The most expensive type of Sphagnum moss is New Zealand Moss. This type will last 2-5 years, and contamination is possible, but not likely. It does not accumulate salt.
The next type is Chilean moss. This type can last 2-3 years. Contamination is also unlikely with this type. However, it does have some potential for accumulating salt.
The last, and least expensive type, is Chinese or Japanese Moss. It is more likely to have contamination. It accumulates salts easily.
So, reusing New Zealand Moss is a good idea. It’s unlikely to be contaminated and doesn’t accumulate salts. Chilean moss doesn’t hold up quite as well, but it’s reasonable to reuse it in some situations.
Japanese or Chinese moss shouldn’t be reused. It accumulates salts, and can easily become contaminated. Most importantly, it has a much shorter lifespan. Why go through the trouble of reusing the moss if it will only last a few months?
Depending on what you plan to use the moss for, a high ph may also be a concern.
New Zealand and Chilean moss have a low ph of 4.8. However, as the moss ages, it begins to decompose. This can raise the ph level. Before reusing the moss, it’s a good idea to test the ph.
So, reusing the moss does increase the odds of it becoming too acidic. It’s also another reason reusing Chinese or Japanese moss is strongly discouraged.
Health and Condition of Plant and Moss
When deciding if you should reuse Sphagnum moss, you’ll need to look at the health of the plant and the moss itself.
If the plant has root rot, pests, or any type of disease, do not reuse the moss. This can cause the new plant to also develop the disease.
Next, consider the health of the moss itself. If it’s moldy or slimy, you can’t reuse it. If it’s very degraded or compacted, this is also a sign you shouldn’t use it.
Essentially, you should only reuse the moss if it is still in good condition.
Sphagnum Moss Sterilization
If you are going to reuse Sphagnum moss, it’s a good idea to sterilize it before reusing. As mentioned previously, if the moss is visibly moldy, slimy, or the plant was sick, throw the moss out.
Even if the moss and the plant appear to be fine, you should still sterilize it just in case. Contaminants may be present, but not yet visible.
What You’ll Need to Sterilize Sphagnum Moss
First, you’ll need the Sphagnum moss you want to sterilize. You’ll also need a microwave safe glass bowl, and plastic wrap. Distilled or sterilized water and tongs are also needed. For safety purposes, oven mitts and safety glasses are recommended.
Sterilizing Sphagnum Moss Cycle 1
First, place a small amount of the Sphagnum in a glass bowl. Allow it to soak in the distilled water until it’s completely saturated with water. If you want to speed up the process, you can squeeze and knead the moss as it’s submerged in the water.
Next, be sure there’s enough distilled water to cover the moss completely. Tightly cover the bowl with plastic wrap. Microwave the bowl until the water boils. Once it begins to boil, continue microwaving for two minutes.
Open the microwave to allow the moisture to vent, but don’t remove the bowl for one minute. Before removing the bowl, put on the oven mitts and safety glasses. This will help protect you from steam within the bowl.
Remove the bowl and place it on a heat resistant surface. Use the tongs to carefully remove the plastic wrap. Remember, there’s still hot steam trapped in the bowl. When you remove the plastic wrap, the steam will escape.
Sterilizing Sphagnum Moss Cycle 2
Stir the Sphagnum moss, then flip it over. Use caution to avoid being burned by steam or hot water. Add more water if needed to cover the moss completely.
Apply more plastic wrap. Keep in mind that the bowl is still hot. Microwave the moss again. Once it begins to boil, allow it to keep going for five minutes.
Open the microwave, but leave the bowl inside for five minutes. Remove the bowl from the microwave, using oven mitts and safety glasses. Place it on a level heat safe surface.
Do not remove the plastic wrap. Instead, you’ll allow it to cool to room temperature. Keeping the steam contained in the bowl allows the sterilization process to continue.
Once the moss is cool, squeeze out the excess water. Then place it in a sterile bag. Any Ziploc bag designed for food use is fine for this purpose. You may also use a Tupperware bowl, but it’s a good idea to use a little bleach or sanitizer before using. This prevents any germs from getting into the moss.
Batch Size Considerations
How long to microwave the moss and how many cycles needed should be increased for larger batches of moss.
It’s best to do it in small amounts, following the instructions above. This allows the water to boil quickly and penetrate the moss.
If you choose to sterilize a larger batch, you may need to add one or two more cycle 2s.
Should You Reuse Sphagnum Moss?
Whether or not you should reuse your Sphagnum moss depends on a few factors. First, it’s important to understand that there’s some risk to reusing moss. Sterilizing the moss does reduce the risk of mold or fungal disease temporarily.
However, it also breaks the moss down to a degree. This increases the risk of mold, fungal, and bacterial disease over time.
Your other option is to skip sterilization. This is more convenient, but if the moss is carrying a fungus, bacteria, virus, or pest, it will affect the plant you use the moss with.
Next, you should consider your risk tolerance. Will you be heartbroken if reusing moss leads to your plant dying? If so, then do not reuse the moss. If you are comfortable with a little risk, then feel free to reuse the Sphagnum moss. If you want some ideas for reusing sphagnum moss, you can find lots in our guide here.
Reusing Sphagnum moss does have some risk. It’s also time consuming to sterilize it. However, if the moss is high quality and in good condition, you may choose to reuse it.
Be sure that there’s no disease present in the plant, and that the moss isn’t moldy, slimy, or decayed. It’s best to reuse New Zealand Moss, and it’s not recommended to reuse Chinese or Japanese moss.
(Header Image Credit – Andrea Pokrzywinski)