6. Is mine a dud?

Probably not. Your mushroom grow kit is made as part of a batch of about 10-15 bags. So, if it were a dud it would probably mean that the entire batch is similarly affected. Because of the cost involved in replacing a batch we are highly motivated in maintaining strict quality control. However, if it did turn out that we had made a bad batch and we would know that quickly (as we keep and observe a control bag from each batch), we would replace the bag without hesitation.

Environmental Factors: Generally, any issue with an individual bag is usually related to the unique variables in your home. These signs often include:

Contamination: Less frequently we will encounter some contamination like mould. In most cases, the mould will clear up, as healthy mushroom mycelium will either contain or kill it. We will generally replace a bag that has become mouldy if the mycelium is too badly affected to recover. Most often the mould has entered after the bag was made, via the air holes. Oftentimes, it's after a person has oversoaked the bag during rehydration.

Our Method: We have a production method that is reliable so we can ensure consistency across many batches. The only variable is the grain spawn used to make the batch (there is one bag of spawn per batch). Issues with spawn would be due to contamination of the spawn and would affect the entire batch. For us, this would be rare as we have a laboratory clean room where the cultures and spawn are made and we have tight protocols to maintain sterility. However, if it does happen this contamination would most likely be mould or bacteria. These are relatively easy to spot, so we would not use the spawn bag for production.

Control Bag: For each batch, we retain a small sample to make a control bag. If you contact us, we can then compare your bag with the control. This gives us better insight into what may be happening, and the advice we can offer to fix problems. It would also alert us to any potential contamination issue affecting the entire batch. Note: We incubate the control bag in our barn. It does not get any special or favourable treatment.

Our Support: We pride ourselves in our ability to work with you in having a successful mushroom grow. This means overcoming any issue you may have with the growing conditions. If we simply replace the bag without overcoming the problem, then we potentially doom the new one to the same fate.

If you need support, please contact us using the live chat feature of the website (or by facebook message). Please include a photo of the bag, including the batch number on the side. Also, if you can, the order number.

4. Mushroom pests, what to look out for

There are only two main mushroom pests to look out for. The Phorid fly and the Sciarid Fly (aka fungus gnat). Both of these flies will lay eggs in the holes of the bags. After the eggs hatch, the larvae roam inside the substrate and quickly devour the mycelium inside. Eventually eating through the stem of the mushroom they emerge as flying adults via tiny pinprick looking holes, out the top.

Less of a problem, unless it's growing outside, are snails and slugs. They seem to seek out mushrooms and devour entire clusters overnight.

Note: Although it is still possible, I have not seen any evidence of rodents, chooks/ducks (or our little pig) showing any interest in eating our mushrooms.

The top two mushroom pests

  1. The phorid fly looks similar to a fruit fly or sandfly. It is often seen around the soil of damp pot plants. Its larvae are tiny white wiggling maggots, Sometimes they are hard to see without a magnifying glass.
  2. The scarid fly has long legs and a slender body so looks more like a mosquito. Its maggots are much larger so generally easier to spot. They are white, plump and often with a blackhead.

If you have the bags inside, these pests are not usually a problem unless you have pot plants already infested, or a problem in the garden outside the window. If you are growing outside you have a high chance of meeting them.

Signs: How to tell if you have them

  1. You may notice the larvae crawling out of the mushrooms after harvest (or inside the bag near the holes). If you put the harvested mushrooms inside a plastic container and in the fridge, the cold will usually drive them out and you will see them in the container.
  2. You may see what looks like pinpricks on the cap. This is where the adult fly has emerged.
  3. The stem of the mushroom will be weak and crumbly (as they tunnel through). The stem may be so weakened that the mushrooms will just fall off and look rotten.
  4. If badly infected (older bag) you may notice the otherwise healthy white mycelium become thin and patchy, signs that it has been eaten.
  5. If slugs the caps will look like something's been eating them

What should I do if I see them?

We use yellow sticky fly traps that you can buy from garden centres or hardware stores. These will catch the adult flies, breaking their breeding cycle. The traps are useful, and they provide a good indicator of having a problem or how big the problem is. If you are inclined to use sprays, use organic ones containing Pyrethrum. These are more for management before you have a problem, as they may not cure a massive infestation.

What if I accidentally eat them?

Firstly, don't panic, they may look gross but are not harmful... to us at least. They have happily been munching on a diet of mushrooms inside an essentially sterile environment. They are very common inside wild foraged mushrooms.  In the future, they may even end up on the plate as a form of future protein.

Further research

Factoid: These last two articles are from PennState University. Pennsylvania has a massive mushroom growing industry, hence very solid research.

Have other problems with your mushroom grow? Here's our article about the two most common issues: https://mycobio.co.nz/knowledge-base/if-it-hasnt-gone-as-expected/

5. I see mould, is that a problem?

It is very unlikely you will get an outbreak of mould. But, mould is perhaps one of the most opportunist and pervasive lifeforms on the planet, so it can happen. However, Shiitake & Oyster mushrooms have had millions of years perfecting the art of dealing with it so are fairly aggressive. If you have an outbreak here's what you can do

  1. Put some tape over any holes directly over the mould. This will deny it oxygen and contain mould spores inside the bag.
  2. Use a marker pen to put an outline of the outbreak. This will more easily indicate if it's growing or receding.
  3. If it looks like it's spreading or the outbreak happens in the first 2 weeks - contact us on the live chat and attach a photo of the mould plus one of the batch numbers on the bag.

Note: For every batch we make (with about 15 mini-farms per batch), We also make a small control bag that we keep in the lab. This way we can monitor what's been sent out. For instance, check how long the batch is taking to pin or if we have a mould problem with the batch (extremely rare). Giving us the batch number allows us to check your mini-farm with the one in the lab.

A note on mould

3. Misting & Humidity

Mushrooms need high humidity when they are growing. So, it's only at this 'fruiting' stage - from pinning to harvest- that you need to care for them. When it's incubating or dormant (between flushes) you do not need to care for it as long as you have it properly hydrated. At that stage all the water it needs is inside the bag.  The easiest way you can keep the humidity high is by misting.

We recommend (at least until you have learned the ropes) putting it inside your shower cubicle (on a plastic stool or somesuch) after you have showered. Leave it fairly wet in there, and to make doubly certain, mist it several times of day as well. This will be the most humid part of the house.

Quick Tips


  1. Rule of thumb: if you have the mushrooms in a spot where you think damp laundry would dry easily, that is not a good spot!
  2. When not to mist: You do not need to mist it UNTIL the baby mushrooms start growing. The water it needs is already inside the bag... unless the substrate has dried out (see post-harvest care for more information).
  3. Be vigilant looking for baby mushroom growth: After you receive the bag, keep a close eye on it because it may start growing at any time. They grow quickly, so you'll need to mist (or put it in the shower cubicle) as soon as you see activity.
  4. The first 8 hours are very important: If it starts during the night and it's in a bad spot, or you fail to get to it in time: it may stall. The Pinks are very susceptible to this. This means they will not bother to grow and will wait till more favourable conditions. See post-harvest care for what to do if this happens, as you will need to clear the air holes.
  5. Learn your unique humidity needs: There is no easy or right answer as to how often to mist. This will be dependent on many variables unique to your environment. However a good rule of thumb, and until you are comfortable with how they are behaving (in other words, your ability in hearing what they are telling you), mist as often as you possibly can. 6 or 8 times a day may not be sufficient for the location you have put it. I have yet to hear from any of our customers who over misting ...but many have failed by underdoing it.
  6. Still uncertain?: err on the side of caution, at least until you have had your first flush and have 'learned the ropes. The best place in the house will be inside your shower cubicle. After you've showered put the mini-farm on a plastic stool inside, and close the door. Leave it wet in there, so don't squeegee out the drops. If you are going out for the day, briefly run the shower on them. Tepid water is best. If you have made them completely wet, make sure they have had time to dry a little before doing it again. Else you may notice they will go a little slimy.
  7. Build a himidicrib. Here's a link on how you can build a simple mini-greenhouse. https://mycobio.co.nz/build-a-humidi-crib/

Little factoid

2. If it's not growing as expected

An important thing to remember, we are dealing with nature. So, it may go as expected even if you followed all the instructions.

Most of our tips are aimed at increasing your understanding of growing mushrooms and managing your mushroom growing environment. In many cases, patience is often the best option, as nature will inevitably kick in (with more favourable spring or autumn-like conditions), but there are things you can still do to encourage it.

Here are the top two problems and what you can do to fix them. Also note, you may experience both of these conditions. This would be indicative that you have not selected a good spot.

1) Pin-set stalling and drying up

2) Dormancy, failing to pin after 4 weeks.

If your grow kit has not started to pin after about 4 weeks it may have gone dormant. This can happen at any time of the year but is more common in summer and the middle of winter. It is caused by a lack of temperature fluctuation.

Generally, the bag will look very well colonised (often very white) as the conditions are favouring the mycelium to grow. It may also develop dark brown patches, which can be a sign that it's starting to get stressed. The mushrooms are simply waiting for a wider variation in temperature, especially fluctuation in daytime/nighttime temperature. So, being inside a well-insulated house it may not feel the fluctuation.

It's usually a simple fix, just leave it outside for a few days.


1.4. Post harvest care

We sincerely hope you've had a bumper harvest from your first flush and looking forward to the second - which should be 2-3 weeks after the first. There are now a couple of things required to get it ready for its second, or subsequent flush. You may also need to do this if you had a failed flush and all your mushrooms stalled. In which case, we call this re-setting the bag.

1. Clear the air holes

Run your hand over the outside of the bag to clear the holes of any debris and nubby bits like pin-sets that failed to grow, or stem stumps from harvested mushrooms. We want these airholes clear so it gets plenty of fresh air and space to grow next time.

2. Check if it needs a drink

Weigh the bag and compare its new weight to its original weight. The difference is the water loss.

3. The Rehydration

Once it's lost about 70% of its water it's time for it to take a dunk. Generally, this should not be needed until after the 3rd flush (or possibly its 2nd if you have it in a dry location). Do this by...

Note: Do not oversoak. This is one of the few things that will harm the mycelium and may cause mould. 

Now you know everything you need, in order to be successful for subsequent flushes.If you do a good job in caring for it, it should reward you for many months to come. We have had customers give us feedback that theirs are still producing after 10 months. However, its yield will diminish as nutrition is depleted. You may want to experiment by adding some diluted liquid fertiliser to it. Use a metal straw, inserted into strategic spots inside the bag.


1.3. Get ready for harvest (about week 3)

Your mini-farm should be pinning or close to it. If it isn't don't worry, every home is different and it may just need a bit more time (see below).

Make sure you are misting it well. Some people move it into a more humid location, like a bathroom for this stage, but the kitchen bench is fine ...or any location that's not too dry! Here's some info on humidity: how to manage mushroom growing humidity

When and how to harvest

A note about the size

There are many things that can influence the size of the mushroom caps. For instance, they may be small if:
Do not let size be the determining factor of harvesting, please harvest on day 5. If you leave them longer than this, they will most likely not grow any bigger, spore and make a mess, and perish more quickly.

If it hasn't started Pinning yet 

If it has not started pinning you could try popping it outside for a few evenings and bring it back inside for warmth. A bit of a cool shock is what it may need as it will think 'winter is coming' and hurry alone. Also, during the winter it may take up to four weeks to pin. If it has taken longer than 4 weeks to grow it may have gone dormant. Here's an article about what to do if mushrooms are not growing.

If you need help please use the live-chat feature on our website.

Recipe Research

Now would be a great time to find some great and hopefully new recipes. We have recipes on our website.


If you have the time, please also let us know the weight of your harvests. It's important data for us. Every home is different and every mini farm is unique, so it's hard for us to predict what type of yield you will get, so this information helps us to set an expectation for others.


1.2. Get ready for pinning (about week 2)

Although the mushrooms are not growing yet, your Mini Mushroom farm should be showing signs of life. You may be noticed the mycelium starting to get denser, and possibly it's starting to thicken around the air holes. The baby mushrooms starting to grow out of the holes are called pin-sets.

NOTE: In summer, pinning may start as soon as 2 weeks (or even earlier), but in winter it may take up to 4. If it hasn't started pinning after 4 weeks it may have gone dormant, so read the article about things not going as expected.

Mist, and mist again.

Remember, you don't need to mist until it starts pinning. But, once it starts, you may need to act quickly to ensure the air is humid enough. Some people are lucky because they live in an area of high natural humidity, or the weather gods have smiled. However, for most people maintaining high humidity will be the biggest challenge.

It is best to err on the side of caution and over-do the misting, especially in the first 48 hours. It's really disappointing to hear from customers who have had their first flush stall in their first few hours of life due to a lack of humidity. If it does stall the info in the above link will help you get back on the right track.


We love seeing how you are doing so please post your progress on facebook or insta and tag us @mycobio. Please also let us know if there's anything we can do to make these tips more relevant or helpful.

If you have any questions, hit us up on 'live-chat' on our website, or send us an email [email protected]


1.1. First steps on arrival

Firstly many thanks for choosing us to be your guides in your fungi journey. Jude and I have only one goal, and that is for you to have an awesome experience growing mushrooms and an awesome experience with us. We sell many many of these little mini-farm grow kits but try to give everyone a personal experience. However, we are a very small business with only the two of us, and sometimes things fall through the cracks. So, if we fail to deliver this please let us know and an opportunity to put it right. Please see the section below if you require care.

We have also tried to make growing our mushrooms as easy as possible. Part of our success has been in the way we can guide you through the grow while you are learning the ropes. When this package is scanned by NZ Post, this triggers our system so you will receive a series of emails with tips and advice, timed to arrive at the different stages of your mushroom grow. (Including this one.)

While you are waiting for the mini-farm to arrive, here's some information to help you start the journey.

The Grow Guide

If you have not already done so, please have a quick read of the information in the mushroom growers knowledge base. If you are short of time, just scan the questions so you know where to find the right info when you need it later.

On arrival

When the mini-farm arrives there is nothing special required. Just take it out of the box, but leave it in the plastic bag.  Everything it needs is in the bag. Just give it access to some fresh air and a warmish spot. A rule of thumb: if you are comfortable, it will be comfortable. The main thing is not putting it somewhere that's too dry. Keep away from heat pumps, fires, or heaters.

Intermediate care

  1. During this stage, you do NOT need to mist or spray it with water. Everything it needs is right there in the bag.
  2. Leave it in the plastic. Do not open it.
  3. Check that it has air holes punched into the side of the bag. You do not need to make any more or make them bigger. If it doesn't have holes, contact us.
  4. Find a comfortable spot, a kitchen counter is fine. It should be shaded, not too hot or cold and away from drafts. Some suggestions can be found here https://mycobio.co.nz/knowledge-base/where-should-i-put-it/
  5. Over the next two weeks, you can watch the mycelium grow. It's the whitish looking stuff spreading through the bag.
  6. Check for pining. Generally, the mini-farm will start pinning 2-3 weeks after we make the bag. The date of this is written on the bag with the month first (this is the batch number). Most of the mini-farms are made on the day they are sent (or the day before), so the timing of information provided roughly matches the stages of growth. However, you may have received a bag that is a little out of phase, or it is growing super quick.


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