Frequently Asked Questions

Welcome to the Frequently Asked Questions section of Mr. Mercy's Mushrooms, your premier online destination for all things fungi!

Whether you're a seasoned mycophile, a culinary enthusiast, or a newcomer eager to explore the fascinating world of mushrooms, our FAQ is designed to provide you with answers to your most pressing questions.

Dive in to discover helpful tips, learn more about our products and services, and make the most of your journey into the enchanting realm of mushrooms with Mr. Mercy's Mushrooms.

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Grow at home mushroom kits

It’s been weeks, and my mushroom kits aren’t producing. What gives?  

There are several things that might prevent mushrooms from growing on a typical timeline.
Air and moisture: First, it’s important to remember that to start growing, mushrooms need fresh air, water, and the correct temperature range. To ensure your kit is getting enough air, make sure that you have cut through a section of the plastic growing bag and that the growing media inside is exposed. If you have been covering your kit with a piece of plastic to prevent moisture loss, try taking this off. It is unlikely that your kit needs more water if it hasn’t yet started fruiting, but to make sure, you can weigh your kit to check for water loss. All kits should be between 5 and 6 lbs when new, so if yours is substantially less than 5 lbs you may wish to mist heavily and frequently or cover loosely with a sheet of plastic. 

Temperature: All of our Grow-at-Home Kits should produce well at room temperature (20℃); if your fruiting environment is substantially warmer or colder, then this may be preventing growth. Also, if your growing environment is on the warm side, there are a few species that will need a cold shock before fruiting (shiitake and chestnut mushroom). To accomplish this, you can simply place your kit in the refrigerator (or outside if nighttime lows are below 10℃) for 24hrs, then return to the fruiting room. 

Fruiting location: Another common issue is that your kit is fruiting, just not where you thought it would be. Examine all sides of your kit, and if you see mushrooms forming under the plastic at a site far away from your cut, simply make another cut to free the mushrooms you see.

My mushroom spawns are spindly, with long stems! 

Mushrooms are very sensitive to CO2 levels. If you see long stems developing, this is literally your mushrooms straining to reach fresh oxygen. Remove any plastic cover that you have in place, and make sure there is fresh air circulation around your kit.

My mushroom kit mushrooms look orange-brown, or dry.  

You need more water! If you’re growing indoors and your home is dry, it’s recommended that you cover your kit very loosely with a sheet of plastic to prevent moisture loss. Try to mist your mushrooms at least twice a day if they look dry.

My mushrooms are moldy!  

Molds thrive in high-humidity environments with low airflow. If you see mold, immediately cut off any affected areas, make sure your kit has access to fresh air, and stop watering for 1–2 days.  Mushroom blocks may eventually start to mold if kept for longer than the recommended two flushes.  If this is the case and you’ve harvested mushrooms several times already, your block has had a good life, and now it’s time for it to rest in the compost.

I’m having trouble getting a second flush out of my mushoom kit.

Most varieties are capable of producing at least two flushes, but these are sometimes unpredictable. We recommend stopping watering your kit for at least a week between flushes. When you start watering again, this can cause the block to initiate the development of a new crop. If all else fails, try leaving the block outside and exposed to the elements; I’m always amazed to see how many mushrooms fruit off of my pile of “waste” blocks!

Dowel Spawn Growing Questions

My mushroom spawn project got delayed. How do I keep my spawn fresh?  

If you won’t be using your spawn within two weeks of receiving it, we recommend that you refrigerate it. Left at room temperature, it may eventually start forming mushrooms right from the dowels! Although some species of mushroom will survive freezing, this is not a recommended method for storage.

What are these little grainy things in with my mushroom dowels?  

They’re grains—specifically rye. We use a small amount of grain spawn to inoculate the sterilized dowels. These grains are not meant to be used for inoculating logs directly; they can be discarded or composted.

When will my mushroom spawn log fruit?  

The average time from inoculation to fruiting is about a year, though this can vary depending on species of mushroom, species of tree, and the spacing of the dowel holes. Make sure your log is stored out of direct sun and gets adequate water, either from natural rainfall or periodic sprinkling/soaking. Usually by about 6–9 months after inoculation there are some visible patches of mycelium in the ends of the logs, following the pattern of the dowel holes [pic]. Once these patches join together, your log may be ready to fruit!

What is the difference between “cold weather”, “warm weather” and “wide-range” shiitake mushrooms?

These are three separate shiitake strains that are all suitable for log growing. They fruit at different times and in different ways.  The “cold weather” strain will fruit naturally in the shoulder seasons (especially fall) when a change in temperature and humidity occurs.  In contrast, both the “wide-range” and “warm weather” strains can be force-fruited (see the explainer below); the warm weather strains can tolerate temperatures up to 25C, while the wide range strain prefers a range of around 15-20C.

How do I force-fruit shiitake mushrooms?  

First of all, note that only the wide-range shiitake strain can be force-fruited. Once your log is fully colonized and ready to fruit, immerse it in cold water for 12–24 hours. The combination of the cold and the added moisture will initiate fruiting. After removing your log from the water, it should start to fruit within one week. Once mushrooms are harvested it is recommended to rest your log for 8 weeks before fruiting again. We like to have a bunch of logs in a rotation to get consistent mushrooms throughout the growing season!

Fresh Mushroom Questions

The mushrooms I bought from you look funny. What do I do with them?  

Luckily for you, you can use our funny-looking mushrooms in any recipe that calls for boring regular ones! Although all of our mushrooms have different flavour and texture profiles, they are all great alone or in combination in stir-fries, soups, pastas, on burgers, or as a side dish. Or to appreciate the subtleties of each mushroom, you can try them individually in a simple sauté. Just heat up a generous amount of your favorite cooking fat in a heavy-bottomed pan on medium-high; rip mushrooms into strips and add, making sure not to crowd the pan; add salt, pepper, and garlic powder if desired; and cook for 2-3 minutes on each side until the mushrooms are slightly crisp and have released their juices. Serve hot and enjoy!

Are your mushrooms good for me?  

Absolutely! Even mushroom varieties like oyster and shiitake, which are not traditionally marketed as “medicinal” mushrooms, have lots of health benefits. They are a good non-animal source of protein, with values between 15-40% by dry weight. They also are rich in B vitamins and trace minerals, and can even be a good source of vitamin D. All this is in addition to any specific medicinal benefits, which vary substantially by mushroom, but can include: lowering cholesterol, anti-cancer activity, immune support, nervous system and brain support, and much more.

Can any mushrooms cause allergic reactions?  

As all of our mushrooms are different species from each other (and from the white or brown button mushrooms you might be more familiar with), there’s always a chance that you might have a sensitivity when trying a new food for the first time. However, adverse reactions to any of our mushroom varieties are extremely rare. If you are concerned or have known allergies to similar foods, make sure to cook our mushrooms thoroughly and only try a small amount when consuming them for the first time. In our time growing mushrooms, we have only heard first-hand reports of negative reactions to lion’s mane, never to oyster mushrooms, shiitake, or other commonly cultivated species. The mechanism behind this is unclear, but reactions to this species are still very uncommon.

Are your mushrooms gluten-free?  

Mushrooms are all naturally gluten free, but this isn’t as weird of a question as you’d think. We grow on a certified-organic medium that includes wheat bran as a nutrient additive to boost yields. None of the gluten from this substrate is transferred directly into the mushroom, but there is a very slight chance that tiny pieces of the growing medum could end up on the fresh mushrooms. We trim all of our mushrooms very carefully at harvest, and we don’t believe that this should be a concern for most gluten-intolerant folks out there. However, we don’t have a certified gluten-free environment, so if you are extremely sensitive you should use your discretion.

How long will my mushrooms keep, and how should I store them?  

We harvest mushrooms daily (twice daily in the summer), and aim to deliver to our clients within several days of harvest whenever possible. If you plan on storing mushrooms before using them, they should be kept refrigerated in a porous container to avoid condensation. A brown paper bag works great for this. Stored this way, mushrooms will usually last up to a week. If you forget about your mushrooms and they look dry but don’t show other signs of spoilage (wetness, fishy aroma), they can still be used—just add some extra water when cooking to rehydrate.

General Mushroom Spawn Questions

Are your mushroom spawns certified organic?  

It’s complicated. All of our products are certified organic, but we use a BC-based certification body (shoutout to Kootenay Organic Growers Society!). This means that our certification is only valid in BC. Since the BC standards mirror the wider Canadian organic standards, for all intents and purposes our spawn is organic. However, if you’re a certified organic grower in Quebec who wants to use our spawn, your certification body may not recognize our spawn as an approved input. Sorry about that, Rest of Canada.

I’m a producer/hobbyist/someone who grows a lot of mushrooms. Can I get a bulk deal on spawn or fruiting blocks?  

Yes! We’ve got several tiers of discounts depending on order size. Most of the overhead in spawn and kit supply is in marketing, packaging, and client support, so if you want to take a bunch of blocks and then leave us alone we’ll give you a fantastic deal. Email with all enquiries.

I see some products listed as out of stock on your site. When will they be available again? Can you do custom orders?  

Some items have only seasonal availability (they’re normally available when we’re making them for use on our own farm), but anything can be custom ordered out of season. Lead times and additional charges may apply. Please send us an email at for rates and availability.

I’m a mushroom growing beginner.  What mushrooms can I grow that will be really easy?  

Our Grow-at-Home Kits are our most user-friendly option, and of these we recommend blue oyster as an especially forgiving variety. Also, if you have an outdoor space you’d like to grow in, king stropharia produces huge amounts of mushrooms very reliably, and is quite tolerant of a diverse range of growing conditions.
What’s your favorite colour?  
Kind of a golden orange-yellow, like light on fallen leaves as the sky briefly opens on a rainy fall afternoon.

I want to learn more about the process of growing mushrooms.  Can you help?  

Yes! We’re  offering a hands-on learning opportunity called Mushroom Club on our farm in Kaslo this year. Or if you’d like a more personalized consultation or mentorship, please reach out and we can chat! Robin also leads mushroom foraging workshops through Selkirk College

I want to start growing mushrooms in my garden. Got any tips for outdoor cultivation?  

Besides obligate-outdoor mushrooms like king stropharia and shaggy mane, many of the mushrooms we stock can be grown successfully outside in beds with a little know-how. First, it’s always a good idea to clearly define the edges of your bed. We do this by creating a bed right on the ground and using logs for the outer edges. This confines the mushroom mycelium to a small space, which helps to trigger mushroom formation once all of the available area has been colonized. Some form of casing material on the top of the bed is often useful; this could be leaves, straw, soil, or even cardboard, and it will help to keep your bed moist, which in turn will help with mushroom formation. Wet cardboard is great for putting directly on the soil at the bottom of your bed. This will inhibit weed growth and is also a fantastic material for many mushrooms to grow on. Species that can be effectively grown in beds include many oyster mushrooms, chestnut mushrooms, and nameko. Most hericiums (lion’s mane and bear’s head) and shiitake are not good choices for growing in beds.