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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)
Top quality, not the best yield
I found the manual to be a bit inconclusive, because it said nothing clear about how often to mist and it was a bit confusing about what's to do with a heat map and what to do without one, so I didn't get the best yield so far (about 18g dried after the second flush). But when the second flush didn't work as expected, I put the cake upwards, and then the little friends started growing big. They're strange fellas, with a huge stem and big (one ended up with 2.5g dried).

Nonetheless, the quality and potency is superb. I found them tasting good, too. I took the whole first flush at once and for the second time in my life I talked with the mushroom spirit. I'll certainly go for it again, hopefully with more experience and a better yield then.
Review by Fungus Speaks (Posted on 6/19/2019)
Nice Kit
Got good decent, very fast growing flushes. Very resistent to bacteria. Review by Nico (Posted on 6/18/2019)
Pretty good
I received another one of these because the first ones where probably duds.
Shipping was both times super fast
And thanks to the great support friends and myself had a pretty nice journey after all. Quite good yield, but i am sure i could have done better with more experience.
3. flush was the max
Looking forward to the next try
Review by Ced (Posted on 4/16/2019)
this shroom den megalonane
i hav problem with tis kit. Review by Vasilis (Posted on 12/26/2018)
Great Service
I didn't get much of a flush from this kit though it was my very first and I'll do a lot differently next time. What really impressed me was the amazing service received from Magic Mushrooms Shop. Fast at replying to my query and fast shipping. Perfect customer service.
As for the effects, I'm yet to try so can't comment on this aspect.
Review by Chela (Posted on 12/22/2018)
Lot of muchrooms on 1 month
Lot of muchrooms on 1 month Review by Rodrigo (Posted on 12/12/2018)
alltou, the first time i grew mcknnaii couple years back, it was only sucsess!! the grow was easy, and suprisingly many flushes.
& the feed back from people, awsome. especially from people who had try mushrooms before, they sad it was really god!
Review by david (Posted on 11/23/2018)
delivery and everything was great.
i dont know, probably i did some things wrong..
it tok many weeks ca3 , 4weeks until small heads showed up, and now the surfice is or was a bit moldy.. i tried to follow the instruction.. now im reading the instructions one more time, and i think i open up the top of the bag, little bit. because acording to the instructions, air circulation is nothing to worry about. so i think i ty that(:
Review by david (Posted on 11/23/2018)
Strong but not in numbers
This time average first harvest, second a few and third only one. Many grow on the side and buttom so I dropped the container, let them grow on all sides. Maybe best just to force them to grow only on top side. Review by J.J. (Posted on 11/21/2018)
They give a decent yield and a real powerful trip. The tub and substrate do have a bit of a gap between them so lots of the shrooms will grow on the sides. Review by MIslas (Posted on 10/24/2018)
Very good product
One of my favourite. Thanks a lot. Review by Adam (Posted on 9/6/2018)
The yield was not as big as I would wish for, but the kit itself is really quite resistant to infection and therefore fool-proof.
You can really notice the blue psilocybin all over the shrooms. Plus I noticed that the dry ratio was higher than other kits.
Trips were pleasingly visual starting at low dosage...
Review by Jiri (Posted on 8/21/2018)
Very good product
5* Review by Iffy (Posted on 7/6/2018)
Very good product
The kit came quickly as always however there was a blue spot which worried me at first thinking the worst but knowing the guys here would help me. Rest assured i was told it was a bruised spot and continued on and the results were great. Lovely flush. Would and am buying again. Review by Iffy (Posted on 7/6/2018)
Great potency, strong effects
It was my first kit, and it was really easy to grow them. I got 20g out of two flushes and the third one is coming soon. I expect a total of 35-40 g out of this kit. The effects are awesome, and really strong. Would recommend. Review by Attila (Posted on 6/8/2018)
This shrooms are perfect
Everything was perfect ! Delievery was perfect Review by Gvantsa (Posted on 6/1/2018)
Really Small Harvest-first flush ok, second 2 fruits, 3... none. Old kits were better!
This is my fourth growkit, and the most disappointing in terms of harvest. The first flush was smallish/normal, the second only three fruits and then the third didn't come at all. The old style of kit I got 4/5/6 flushes easy, smaller each time but still, even the third flush was bigger than the first with this new style.

20ish g dry... it's really not great-the old kits were far better. The shrooms themselves are ok-pretty much the same as the Amazons and B+ in terms of trip, maybe less potent as taking a 5g amount it was still quite mild experience, no ego death. Again, with such a small harvest maybe the potency was also not as good as it should be.

Anyway, I use a heat mat and follow the instructions as before when I had good results so I don't think it's user error but you never know...
Review by Donatas (Posted on 5/28/2018)
Kit worked perfectly
Great kit first shrooms ready to pick within 3 weeks. Only issue Was a gap between tub and substrate which caused shrooms to grow out the side and underneath of tub.

Overall harvest roughly 40g dried after 2 harvests.

Best visuals I’ve experienced on these badbois
Review by C (Posted on 5/13/2018)
Amazing people.
I'm over 40 and have enjoyed the shroom community for nearly 30 of them, to that end my review is more about the service i've received. These guys are awesome so helpful and very very quick discreet delivery of a top quality product. I've progressed from the kits which are so easy to use to now self germinating/inoculation. Using all products again from magic-mushroom-shop. Thanks again and again and again. Peace. Review by Iain (Posted on 5/10/2018)
Snelle levering! Fijne shroom, dacht in het begin dit wordt niks maar wat een mooie vruchten!! Aanrader! Prachtig mooi om te zien groeien en te ervaren Review by Daniella (Posted on 5/7/2018)

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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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