Choosing Straw for Oyster Mushroom Cultivation

Choosing Straw for Oyster Mushroom Cultivation

Sep 8th 2025

Oyster mushroom cultivation on straw is a popular way to grow an abundant harvest of these delicate mushrooms. The first step in this process is to choose suitable straw for the process- below we'll offer a few guidelines on what to look for.

The first thing you will want to make sure of is that you are using straw and not hay. Hay is the nutritious part of grass that is often used to feed animals.

green hay
Hay

Similarly, straw that has a lot of weeds will give the substrate a nutrition boost that bacteria loves, but oysters do not need. If you use either weedy straw or hay, the substrate overheats, leaving the oyster mycelium trying to survive is a less than ideal environment. 

weedy straw
Weedy Straw

clean straw for oyster mushroom cultivation
Clean Straw ideal for oyster mushroom cultivation

The ideal straw will be golden-yellow and weed-free. Wheat and oat straw are the two top contenders for successful production. You can use other straw alternatives such as barley, rye, corn stover, or rice straw, but you will need to work with them to improve their structure. Some substrates collapse easily or are too wet or thick so a little experimentation can improve your results! One final thing to consider is the straw particle size. We chop our straw here at FFP to the 4-6 inch length. You do not have to chop your straw, but it does make it easier to pack down into bags. You do however want to avoid pulverized straw. Too small of pieces can result in too dense and heavy of a pack, thereby suffocating the mycelium.

All in all oyster mushrooms are a forgiving species, so if you're keen to give it a try don't hesitate!

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