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Magic mushroom grow kit McKennaii XP by FreshMushrooms®

The way the McKennaii magic mushrooms grow is as outlandish as their effect. The caps go from big to small, straight to bent, thick to thin stems, light color yellow to dark brown. Be prepared for anything. The trip can go deep, colorful, speedy and sexual.

Availability: In stock

Product Description

Growing with the McKennaii XP Fresh Mushrooms Grow Kits is extremely easy. These kits are completely maintenance-free thanks to a fully colonized substrate without fillers. You hardly have to do anything to get your first flush with high levels of psilocin. Follow the instructions below and you will be assured a high harvest of mushrooms!

  • Fast growing: 1 week to first pins
  • High yields: Up to 4 flushes. (in ideal conditions)
  • High Potency: According the supplier the XP (Extra Potent) strains are twice as potent!

Contents of McKennaii XP Mushroom Grow Kit

  • 1x McKennaii Mushrooms Grow box – This contains rye substrate with active mycelium
  • 1x Growbag – The bag has filters across the bag.
  • 2x paperclip – For closing the grow bag.

You need

  • Misting Bottle  – Misting is needed for the humidity level
  • Potable water – For misting and soaking
  • Clean environment – Work clean to give other fungi and bacteria (micro organisms) no chance to contaminate.

We recommend using

How to prepare the room and yourself before you begin

  • Close any open windows. Wind or draft may bring micro organisms that can contaminate the Magic Mushroom grow kit.
  • When taking out the grow box with the cake from the carton box, put it on a disinfected surface. If this surface would not be clean, micro organisms may attach to the grow box and will flourish inside the Magic Mushroom grow kit, and will contaminate the grow box.
  • Make sure you work with clean hands and arms. We recommend using surgical gloves or a good disinfectant when handling the kit. You should use a facemask to avoid breathing into the grow bag and on the cake.

Instructions: Starting the McKennaii Magic Mushroom grow kit

    1. Take the magic mushroom grow kit, plastic bag and paperclip out of the box. Remove the lid of the mushroom grow kit (store the lid properly). Rinse the lid under running water. You will need it again later (step 7).
    2. Place the mushroom grow kit without lid in the plastic grow bag (opening at the top). Slide the opening of the bag under the bottom with the micro perforation pointing upwards. The opening of the bag is now largely closed. You do not have to worry about air circulation.
    3. When you see the first small mushrooms ( called pins), you can put the grow bag upright. Do not water! The first magic mushrooms will be visible after about 1 week.
    4. Place the mushroom grow kit in an area with enough daylight and at a temperature between 18 °C and 28 °C. NEVER place the grow kit in direct sunlight. Although mushrooms will grow at almost any temperature above 15 °C, 23 °C is the ideal temperature for an optimal harvest. Special heat mats are available to ensure this temperature and not have to heat the entire room.
    5. When the mushrooms are slightly bigger as the pins keep the bag a bit open the entire time so the moisture can evaporate (Phase 2). Too much moisture is not good.

The first mushrooms will be visible after approximately 1 week. Your first harvest will be about a week later. Make sure that you harvest before the first spores begin to fall! Freshmushrooms grow kits produce their first harvest fairly quickly. The first buds are already visible after only 1 week. Low and high temperatures may slightly delay this growth process. As soon as the buds are visible, stop spraying the inside of the bag. It usually takes one to two weeks before the mushrooms are fully developed.

  1. These kits can produce several mushroom harvests. To do so, fill the kit with clean tap water after the first harvest. This process is known as cold shock. It breathes new life into the mycelium and ensures that enough moisture is present for the mushrooms to grow.
  2. Place the lid of the grow Kit back on the kit. Let the kit rest for 12 hours. Open a corner of the lid and drain the excess water. From here you can follow the instructions from step 1 again. This process can be repeated several times.

Growing with a heatingmat (use only for this brand)

Place the plastic bag with the Grow Kit in it on the heat mat. Switch the heat mat on. After two days switch the heat mat off and wait until the buds have developed, which usually takes between five and ten days. Then switch the heat mat on again and open the top of the bag a little so the moisture can evaporate.

What to do if the buds haven’t developed after ten days. Take the cake out of the plastic box, put it back in the plastic box on its side and start again with two days with the heat mat.

How to store the grow kit correctly

It is recommended to start the cultivation process right away. If you decide to start growing later, you may store themagic mushroom grow kit inside a Soaking Bag in the refrigerator (2°C to 8°C) for 4 weeks after the production date.


The ideal temperature is 24°C. Do not have the temperature drop under 18°C and not exceed 29°C. To keep the temperature from dropping under the 18°C, you can use a thermo mat to maintain the ideal temperature. A thermo mat is a must-have in the winter or colder regions of the world.


The magic mushroom grow kit only needs light for the mycelium to ‘understand’ it has reached the surface. Only then, mushrooms will grow. A few hours of fluorescent/artificial light or indirect sunlight a day is more than enough. Direct sunlight kills the mycelium, so avoid the sun to shine directly on the grow kit.


If the conditions are optimal, you can expect the first small mushrooms (the pins) to appear between 7 and 10
days. This also depends on the strain. Some cubensis strains grow slower than others.


The mushrooms come up in groups. This can be a small or large group. That depends on the strain. A growth like this is called a flush. Mushrooms are almost never ripe at the same time. You can get more than one flush out of a kit. The first two flushes are the largest. When more flushes come, they will be smaller than the previous one.


Mushrooms are ripe and should be picked when the veil between the hat and the stem has just torn. Don’t wait much longer. Use surgical gloves or disinfect your hands, wrists and arms. Pick the mushrooms that are ripe and let the others continue to grow. The cake has no top layer such as vermiculite. This makes is much easier to pick the mushrooms than with the standard grow kits. The mushrooms can easily be pulled out of the cake by holding them between thumb and index finger. They mushrooms let go almost immediately. When most of the larger mushrooms have been picked, also pick the smaller ones and the pins as well.

Mushrooms that grow from the sides

Mushrooms grow where the light reaches and where there is little penetrating resistance. Because the cake has light shining on the sides, the mushrooms might also grow there. It is hard to counter this and can be allowed. Some growers wrap the sides of the grow box in aluminum foil to keep the sides dark, but this doesn’t always work well.

When mushrooms grow there, they can be picked just before you soak the kit:

Clean hands! Take the grow box out of the bag and place it upside down on your other hand. Wiggle the plastic box so that the cake will fall out, onto your hand. The plastic box can be placed on a disinfectant surface. Now you have this hand free to pick the mushrooms from the sides of the cake. When all mushrooms are picked, you can place the cake back as it was, in the plastic box and continue to the soaking process.

The end

When no more mushrooms grow out of a grow kit after the second flush for at least three weeks, or when the Magic Mushroom grow kit turns green, red, grey or yellow; the grow kit can be disposed of.  The change in color is a sign that the grow kit is contaminated with another fungus or a bacteria. No more mushrooms will grow out of the Psilocybe cubensis Magic mushroom grow kit and the grow kit should be thrown away in the garbage outside.


When you are too late picking the mushrooms, they will drop their spores. The cake and the mushrooms will turn black/purple (some other cubensis strains red/brown) because of the spores. This is not really a problem; it just doesn’t look very pretty. When mushrooms release their spores, they also start to degrade and the active ingredients are breaking down. Mushrooms will lose some of their potency.

Be sensible

Check out the responsible use page for more information on do’s and don’ts.

This kit is meant for small-scale home use only.

Additional Info
Additional Info
Productcode fm-mck
Weight (KG) 1.1000
Grow Kit type FreshMushrooms
Difficulty Easy
Size Normal
Species Psilocybe cubensis
Origin Netherlands
Potency Average / High
Optimum cultivation temperature 24ºC
Yield (from) 100 grams
Yield (to) 300 gram
Water Spray Needed Yes
Not shipped to: Non EU countries, Africa, Asia, Australia, Caribbean, Central America, Cyprus, Denmark, Germany, Iran, Ireland, Middle East, South America, Canada, Estonia, Finland, Israel , New Zealand, Norway, Russia, Sweden, Switzerland, Turkey, United Kingdom, United States
Customer Reviews (67)
Starting about 10 days after the kit arrived, it starts sprouting like mad. Probably around 40 shrooms, different sizes. 1 large one is enough for a (mild) trip, so I've got a jar in the freezer with a dried supply that will last me for months. Had good times clubbing, and taking them at festivals. They brighten up the day, add a bit of energy and humour. Review by Adam (Posted on 5/12/2020)
Contaminated out of nothing
Got three kits. One of them was mckennai. Did exactly same things for three but this kit contaminated. Shop never replied back for making up. Review by alexandros (Posted on 5/8/2020)
Not good
Waste of money .took three kits and I did exactly the same for three. One of them was Mckennai. Its was contaminated out of nowhere.Only this kit. So I can't say that it's a mistake from my side since the other two were fine by doing exactly the same. Review by alexandros (Posted on 5/8/2020)
Four flushes with decreasing yields and potency
Again this might be down to the way I'm doing it but the yield was decreasing with every flush. First I got 15, then 8, then 4 then just 3 shrooms. At least this kit seems robust enough to survive the environment I'm growing in. Very quick to fruit. Saw pins on the 3rd day. Fruiting time goes down with each flush. Can see pins on second day and fully grown shrooms on 4th day from the second flush onwards Review by GMan (Posted on 5/8/2020)
Easy to grow and decent first flush
I got a good first and second flush. The third one wasnt great though. Review by Eoin (Posted on 4/26/2020)
Easy to grow and decent first flush
I got a good first and second flush. The third one wasnt great though. Review by Eoin (Posted on 4/26/2020)
Not extra potent, small yields
I'm really sorry, but this was just a total waste of money

So 4 main things here
-It took them 2-3 weeks for the first mushrooms to show
-Gave only about 2 waves of mushroom which again took forever to grow
-Not potent, they have the same potency as any cubensis so nothing special
-Very small yields, gave about 7g per wave so max a total of 15g per total

Something worth mentioning is that i ordered them in the holiday season before x-mas, so that may have influenced the quality of the product since there is a lot going on in that period

Bought 3 of these XP boxes thinking it will be awesome to try something stronger, took the same dose i usually do and felt nothing different. Tried multiple times in hopes of getting different results because everyday moody mood may also affect how you feel the shrooms. Unfortunately after testing them over a couple of months i can say they are not any special to other cubensis regards potency.

What i liked about them tho it' s their magical looks. Thjey are very mystical, having white dots on their caps just like amanita muscaria and grow very robust with dark brown chocolaty veins on their stems. Reminds me of dwarfs
Review by beloje (Posted on 4/20/2020)
Really good service. But disappointed over both growkits.
The first growkit i ordered was bad, i was moldy and lika a week after i set it up it was a gonner. They send me a new one witout any trouble and were very proffesional and polite.
I'm a bitt dissapointed at the yield as i only got like 10-12 grams on first flush. The second flush is now growing with only five mushrooms. Kind of bad ????.
In the past i always got good yields every flush but this were not something i would recommend. Good service minded workers though!
Review by Samuel (Posted on 3/25/2020)
Nice shrooms
Great service, fast delivery and the shrooms grew and worked as expected. I recommend covering the sides and the bottom of the box with tin foil, otherwise the shrooms may start growing all over and that can get out of control. Review by hey_jim (Posted on 12/19/2019)
Light but nice
Not a high visual cubensis.. Nice body feeling.. But light on the effects on my taste Review by Heckel/Ana (Posted on 12/17/2019)
Very little effect even with higher doses
I have grown a lot, I have taken a lot, but I have to say I did not find these a very good strain, actually quite bad. Thin and physically little visible psilocybin when I bruised them with my fingernails. I took them both raw and dried, so it was not the drying process as I had first suspected. So for me, quite a poor strain and one I won't be buying again.

[mms edit: Hi Ross, you might have been unlucky with this one. Please contact support so we can find a solution. ^IQ]
Review by Ross (Posted on 12/14/2019)
Not that good rush or flush
This one didn't gave so many mushrooms and the rush was not that great. Review by Allan (Posted on 11/11/2019)
Great box!
I get 5 flushes qith 4 cold shocks. Total get around 60gr dry shrooms. Great product! And my mycel get contaminated after 2nd flush! Really strong and powerful box Review by Alex (Posted on 10/22/2019)
Awesome growkits
Very good grow kits if you handle them with care. Great quality and if you let them dry you can keep them for months, keep in mind that they will lose strenght so over time the dose has to be a bit more. And service from this site is always perfect! Thank you, love and respect! Review by Lifisgood (Posted on 10/18/2019)
Mushrooms for cooking ?
I ordered this batch twice, got total of 3 batches. First one was wasted since I wasn't prepared to store them. Second and third batches didn't work at all. 0 effect. Just order something else. Review by Mel (Posted on 10/12/2019)
Good service
As always good and fast delivery

Mckennaii was more philosophical so if you are new try mexicana instead
Review by izi (Posted on 9/19/2019)
something wrong
I have already 2 chanche to try,both time i have got 15 g rare mushroom only,and it was taste like nice salad but nothing extra effect.I try to harvest one more time but i feel dissapointed already.

[Hi Digo, that doesn't sound good. Please contact customer support with explanation on your steps and please send in some photos too! *IQ]
Review by Digo (Posted on 7/31/2019)
somehow disappointing
I have large experience using different grow kits and I must say with this one I got really small flashes. Getting 3 to 5 mushrooms only, thanks god the mushrooms were at least big ones. I repeated the whole process (3 times) with the same success. So at the end I got around 20-25 gr (dried) per kit, which is quite low for what I used to get years ago. I'm starting to think that this is a general problem, because I have trying different ones with more or less similar results.

I still haven't tasted them, I just hope the experience worth the effort / price.
Review by Geso (Posted on 7/1/2019)
Gute Sorte
Hat gut geflusht. Weiter so! Review by Marco (Posted on 6/27/2019)
Ich bin sehr zufrieden
Sehr schnelle Lieferung. Sehr kräftig durchwachsener Kuchen. 1.Flush nach 10 Tagen. Trotz warmen Wetter, tagsüber 28°C, habe ich sehr schöne Pilze geerntet. Ein voller Erfolg. Dankeschön MagicMushroomShop. Review by Sven (Posted on 6/22/2019)

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Important information about FreshMushrooms® grow kit McKennaii

  • You have to be 18 years or older to order this product
  • This product has shipping limitations. See the additional information to find out where we don't ship.
  • When you place an order you declare that you are aware of the legal status of the ordered product(s) in your country and that you are allowed to receive and posses these.
  • The use of magic mushrooms is at your own risk, so make sure to be well informed about the use and their effects.
  • The price does not include shipment.
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