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

Use a Misting bottle. You can buy one at the supermarket.
Tap water is absolutely fine (Chlorine is not a problem for them).
Misting/Humidity is more important than temperature once the mushrooms are growing
Drafts, air conditioning/heat pumps etc will dry them out quickly, so be mindful where you put it.
Humidity, at a minimum, needs to be above 85%. Temperature ideally between 16 and 20 degrees.

Advice

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!
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).
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.
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.
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.
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.
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

It's not so much the humidity that is the essential component. What is important is the condensation of the humidity onto the cap and its subsequent evaporation. By way of capillary action, the evaporation allows the mushroom to pull water from inside the bag into the mushrooms swelling the fruit body, so growing it.
You may have noticed that mushrooms will generally grow after rain and only at certain times of the year. However, both the Oysters and Shiitake can be successfully grown all year round, if you can manage the humidity.

Why do you use plastic, is it biodegradable?

Unfortunately, we have not found a suitable substitute for the polyethylene bags, but we are working on it. We are also very skeptical regarding the biodegradable nature of plastic alternatives (biodegradable plastics is almost an oxymoron) all that happens is that the plastic just breaks down into small particles (that we can’t see without a microscope), and leach into waterways to easily get into places they shouldn’t.

If you cannot dispose of the plastic ethically please send it back to us. On the farm, we melt these plastics down into bricks that are used as edging etc in the garden. This way we can manage the waste by turning it into a somewhat solution. We are also acting as custodians of our waste until such time as it can be more effectively processed.

What's the main difference growing Shiitake vs Oyster mushrooms?

The Oyster mushrooms are aggressive growers. It takes them about 3 weeks (incubation) to start growing after making a bag. Thus they do with little intervention. The Shiitake needs 3-4 months to incubate, and then when ready they may still need encouragement to grow if your local climate is not ideal.
The lifecycle of the Shiitake is different from Oysters mushrooms. The Oysters are usually ’done’ after 3 months or so of growing (but you can use techniques to go longer), whereas Shiitake can go 10+.months or over a year.
When growing the actual mushroom, the Shiitake requires less care than the Oysters. It is not as susceptible to stalling due to lack of humidity and requires less airflow.
Oyster mushrooms are fairly aggressive growers, and will often have a very large number of clusters in a flush, whereas the Shiitake has fewer mushrooms, but if conditions are perfect, may continually grow rather than to periodic flush of the Oysters.
Another main difference is that we remove the bag from the Shiitake but leave it on for the Oysters. This is because the Shiitake grows a protective skin and can hold the sawdust together, the Oyster doesn’t.

I see mould, is that a problem?

Generally not. If the shiitake farm is running a little to damp after the soak, sometimes mould may appear. Often the shiitake can fight back and deal with it. If it's struggling or looks like it's getting worse, try dabbing some hydrogen peroxide on the mould. At worst, you may need to carve out the affected part.

If unsure, send us a photo, we can usually diagnose and offer solutions from that.

How often will the Shiitake fruit?

If you are maintaining good conditions, fruit every couple of weeks, producing over a half dozed mushrooms at a time. However, you will need to manage your environment carefully else it will remain dormant until it detects that the environment is right.

Things it likes.

Larger variation in temperature. Especially cooler followed by warmer. This is why it is important to put it in the refrigerator for at least 3 days to chill it down.
You will need to maintain the moisture level of the block. It needs to be damp, but not thoroughly wet or it may fall apart. The best way to maintain its moisture is to thoroughly mist it twice a day. It's okay to wet the exterior when misting. See the section on Soaking.
Keep the block in a damp place. So way from drafts and direct sunlight or a dry heat source (heat pump, central heating etc). If you are struggling, you may want to consider building a "Humidi-crib).
When it is fruiting, mist the emerging mushrooms as often as you can during the day. However, they generally require less humidity than Oyster mushrooms at this stage.

How long will my Shiitake block last?

If you care for it, it has the potential to produce for over 12 months. In our commercial grow we have some that still fruit occasionally after 24 months. However, it’s nature and there are a lot of variables that will affect its longevity. As it gets older its yield will decrease as nutrition is depleted. When you think it’s finally done, you can use it as mulch in the garden.

The main factor that will determine its life is your ability to maintain moisture within the block. Too little and it will just stay dormant and not fruit, but over wetting the block could cause it to deteriorate or encourage mould or other contaminants to grow.

Ultimately, how long it lasts will be up to you.

Can I put my Shiitake block outside?

You can, but it’s likely that pests like fungus gnats will make a home of it and get to your mushrooms first. The larvae stage of the gnat lives inside the farm eating the mycelium and weakening it. They will eventually eat their way through the cap and fly away to lay more eggs. see this article on pests.

Also, slugs will make a feast of it.

In certain situations, we may advise you to put it outside, but this comes with the caveat of dealing with pests.

If you see little critters flying around your Shiitake-farm, invest in some yellow sticky fly traps sold in garden centers.

Do I need to keep it in the dark?

These types of mushrooms grow in the deep shade of the forest, so inside room lighting is about right. It’s doesn’t need light to grow, so it's equally ok in the dark. I prefer to give it a natural environment as possible to stimulate the production of micronutrients.

If it is direct sun, this may cause the Shiitake block to dry out quickly.

Why and when should I soak the Shiitake block?

Note: half the weight of the shiitake-farm is water. So if a 3kg Shitake farm is weighing in at 1.5kg… then it has zero water left. The water inside the bag is what allows the mushrooms to grow (most of the weight of the picked mushrooms is from this water).

CAUTION. Over-wetting the block may cause damage. It has the potential to allow contaminants like mould to grow or it may encourage the block to fall apart.

The best way to maintain moisture in the block is to not allow it to lose too much water in the first place.

Keep away from drafts and heat sources that are naturally drying.
Mist the outside of the block frequently, saturating the surface layer at least once a day.
After it has fruited, take it outside and spray it very gently with a hose. Allow some of that water to soak in before doing it again.
If it is very dry (light) soak it carefully in a bucket of cold water. Tap water is fine. It will be buoyant, so you may need to put something heavy on it to submerge it. Soak for 3-4 hours then let it recover for a few days before doing it again if it is required. Take care handling it when it is thoroughly wet.

If it has completely dried out, Shiitake are very hardy, and it’s likely that it’s okay. Just take care in rehydrating it.

Why (or when) should I put the Shiitake block in the fridge?

In nature, the shiitake will fruit in the autumn (and spring) as it can detect wild fluctuation of seasonal temperature. They can sense when it’s time to procreate. Shiitake are very cold tolerant and in nature may need to live-out winter in a frozen log.

To simulate this, put the block in the refrigerator for at least 3 days. Then bring it back into the warmth.

You can use this technique to encourage it to fruit.