Mold or smell in peat moss? Don’t worry!

Mold or smell in peat moss? Don’t worry!

One of frequently asked questions from clients is what to do if there is mold or smell in our peat moss products!

Clients often complain that after opening the packing there is fungus on the peat surface and smell is weird. What are the reasons and what to do?


Pure peat has up to 98% of organic matter concentration and frequently the fungi are drawn to organic stuff. To make peat a growing medium, it is almost always treated with lime and fertilisers. These chemicals improve microorganisms’ life circumstances and improve growing conditions for the plants.

At this stage, saprophytic fungi (and bacteria) living on dead plant material, as well as airborne spores that are constantly present in the environment, might infiltrate the peat. Substrate packagings with fungal growth should be opened and thoroughly mixed to allow for as much aeration as feasible. The fungal mycelium immediately collapses after aeration. Because the fungi are solely saprophytic, the fungal mycelium causes no damage to the crop.

Fungal growth on substrate surfaces is created by high humidity and damp circumstances and is typically caused by airborne spores. As a result, all preventive and therapeutic treatments should aim to produce a drier environment and guarantee proper aeration of plants and substrate. Implement a dry crop cultivation to enable the substrate’s surface to dry. Reduce the relative humidity within the greenhouse if at all feasible. There is no effective fungicide on the market for saprophytic fungus.

Fungicides have almost no effect on soil, and it does not influence the product quality! Remember to aerate and mix the product thoroughly!


It is possible that odor will arise in compressed peat products. This is possible after a lengthy journey in unfavourable hot weather conditions. The odor is similar to rotting eggs or ammoniac. It is a symptom of anaerobic microbiological activity in the compressed substrate and is aided by high temperatures and low oxygen levels.

Smell is difficult to avoid and examine since it is influenced by a variety of factors, including:

  • Microbiological life in peat
  • Temperature during shipping
  • Cargo lead times
  • Storage conditions after arrival

So far, not much is known about the exact mechanisms, although it is predicted that biological activities of bacteria induce nitrate and sulphate reduction. As a result, there is a stench and, in certain cases, a reduction in accessible nitrate nitrogen in the substrate.

This is not to say that the substrate is of poor quality. Often the substrate can be utilized without restriction if the following preparations are taken prior to use:

If items exhibit fungus or odor, the substrate should be removed promptly to allow the material to aerate. Existing gases can disperse, and oxygen returns to the substrate, halting the activities. If feasible, keep in bulk for a day or two and turn at regular intervals. During aeration, the odor can dissipate.

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