My mushrooms have spored! Should I be concerned?

Ideally, you should harvest your mushrooms 5 days after they start growing. That way you will minimize the mess made if your mushrooms have spored.

If you have experienced a “spore storm” you will know it can make quite a mess. If the air is still, most of it will fall directly under the mushrooms. If you have it placed on a kitchen or bathroom bench, it is usually easy to clean up with a damp cloth. However, the spore is so fine the small air currents in the room will disperse it. So, if you have been away for a few days the spore may have covered a wide area, appearing as fine dust and making it a real chore to clean up.

An ounce of prevention is worth a pound of cure.

Grow the mushrooms in an area that’s easy to clean up. A kitchen or bathroom bench is ideal. Also, keep it away from drafts. (Both of these tips also help with maintaining humidity.)
If you are going away for a few days, put it in the shower cubicle. If it spores, just run the shower.

Do Not!

• Leave the mushrooms growing for longer than 5 days.
• Grow the mushrooms in a general living area.
• Above carpets or next to curtains and difficult-to-clean surfaces
• Never in a bedroom!

How to clean after mushrooms have spored? 

• Use a damp cloth to mop up as much as you can.
• Open windows and doors to ensure proper air circulation while cleaning. 
• Minimise movement so as not to make the spore airborne again.
• Thoroughly vacuum the room with a cleaner that uses a HEPA filter. Most modern cleaners use these.
• You may wish to wear a p2 mask during clean-up, especially if you suffer from allergies.

Quick Questions

Is it dangerous?  The spore load from a single home-sized “grow kit” should not cause any harm. However, it may cause distress to someone who suffers from allergies or asthma. If you suffer any of these please take extra precautions.

It is worth noting that the air we breathe also contains many fine particles, including bacteria, dust, pollen, and fungal spores. These are not usually an issue for most people. As commercial growers, we wear PPE like respirators etc.

Concerned about the spores or mushroom allergies? here is a link with more information: Unmasking Mushroom Allergy: Symptoms, Diagnosis, and Treatment

Will mushrooms grow in my house? No. Other types of fungi can grow in your house like molds etc, but not these types of mushrooms. Fungi generally will only grow on a host (plant or animal) that they have evolved to co-exist with. The culinary mushrooms (like oyster and Shiitake) grow on decaying hardwood trees, so not likely to grow within your house (for instance on a wooden window sill or floorboards, etc).

Facts about mushroom spore.

• Instead of seeds, mushrooms produce spores. When it lands in a suitable place the spore will grow fine filaments (hyphae) which form the mycelium of the mushroom body.
• The spore contains only half the genetic code required for the new mushroom to grow. The hyphae of two spores must meet, so that the resulting mycelial growth contains the full genetic code (a new strain).
• They are microscopic but can appear like smoke or a fine mist rising from the cap of the mushroom with a warm air current.
• Given that a single mushroom can contain millions of spores, the resulting number of new strains created is tremendous. Only a select few of these strains, those best suited to out-competing its ‘siblings’, will dominate. These strains will have had the best ability to adapt to the many variables necessary for them to survive. Principals of Darwinian nature at its finest. This interesting property of mushrooms is why/how they are being researched to digest plastic.
• Once the mushroom has spored, the mushroom cap will deteriorate quickly, which is why it is best to harvest just before it does. Much like fruit left to ripen on the tree will also deteriorate quickly.

Microscopic image of Oyster Mushroom Spore