Organic Shiitake Mushroom Grow Kit Fruiting Block

$29.99

Our Certified Organic mushroom fruiting blocks make growing your own mushrooms easy. Designed by mycologists and colonized to the perfect level, all you have to do is create the right environment and fruit your mushrooms.

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Our Shiitake (Lentinula edodes) fruiting block features a popular strain that produces light brown, medium-to-large, umbrella-shaped caps. Shiitake mushrooms are a delicious edible fungus from East Asia and their flavor is described as rich, savory, buttery, and umami. This strain tends to produce generous flushes, making them a great mushroom for confident beginners and intermediate growers.

Shiitake are reliable producers as long as the ambient humidity in the growing environment remains consistent. Because the block is removed entirely from the bag once it's ready to fruit, shiitake blocks are prone to drying out. Therefore, we recommend using a humidity tent or humidity-controlled fruiting chamber (like a monotub or martha tent) to help mitigate the moisture issue.

Receiving and Storage

Remove kit from the shipping box as soon as possible. Then, unfold the top of the bag, making room for air space. It's also important to check and confirm that the filter patch is not obstructed. This will help the organism breathe and continue to thrive!

Fruiting blocks should be used within 1 week of receipt. If you don't plan to use immediately, you can refrigerate your block for up to 6 months.

Growing Instructions

For best results

We recommend growing your shiitake block in a fruiting chamber (like a monotub or martha tent) as a controlled environment will decrease the risk of contamination and increase the chances of success.

Creating optimal conditions

The environmental parameters for shiitake can be found on this page under "Temp, Humidity & CO2 guide" and on page 13 of our fruiting block instruction booklet.

Preparing your block

Your shiitake block should be given time to brown in its bag at room temperature before fruiting is initiated.

How to initiate fruiting

  • Once the block is mostly brown, place the sealed block in the refrigerator for at least 48 hours.
  • Next, remove the block from the bag and soak the block in cold water for approximately 4 hours before placing it directly into your fruiting chamber.
  • DO NOT place back into the bag, as shiitake blocks grow without a bag.

Special considerations

Shiitake can be prone to Trichoderma (green mold). If you see green mold, spray affected areas of block with hydrogen peroxide 3%.

Harvesting your mushrooms

Harvest your shiitake block just before the caps flatten. Trim flush with the block so no stem remains on the block before subsequent fruitings. Place block back into fruiting chamber between fruitings to prevent it from drying out and to decrease risk of contamination.

Growing different blocks together

With some compromise, many different species of mushrooms can be grown together in a fruiting chamber. First, consider the temperature range of the mushrooms you desire to grow, and second, the CO2 sensitivity. Humidity ranges overlap for the majority of species. We encourage you to experiment with many different groupings!

Troubleshooting

Having issues with unusual growth, stunted growth, or no growth at all? Refer to pages 16-18 of our fruiting block instruction booklet.

Temp, Humidity, & C02 Guide

Temperature 55-70°F  |  13-21°C
Humidity (Phase 1: Primordia)95-100%
Humidity (Phase 2: Fruitbody)85-95%
CO2 Sensitivity (Phase 1: Primordia)500-700 ppm
CO2 Sensitivity (Phase 2: Fruitbody)<1,000 ppm

  • Primordia -  The earliest recognizable stage of fruitbody development. Also known as “baby mushrooms” or “mushroom pins.”
  • Fruitbody - A fully grown mushroom, the reproductive structure of the organism in which the spores are produced.
  • CO2 sensitivity - When CO2 levels are too high, yields will decrease, stems will become long and stringy, caps will be small, and/or growth will halt.

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Frequently Asked Questions

Fruiting block kits are mushroom grow kits, but tend to be larger (5 lbs) and some require a bit more care depending on species. Instead of boxes, they are bagged. We recommend growing them in a fruiting chamber such as a monotub or martha tent set up like our BoomRoom. A controlled environment will produce the best results for the fruiting blocks. And, since these kits are slightly larger, they can produce more mushrooms than our Spray & Grow Kits.

Oyster mushrooms and lion's mane mushroom fruiting block kits are great for beginners because they are reliable producers and require the least amount of effort. Reishi is also great because the mushroom grows in the unopened bag (no special care or fruiting chamber required!)

All kits should grow a minimum of one flush of mushrooms, but with a little patience and skill you can often get a second or third flush depending on the species! After you’ve harvested your first flush of mushrooms, remove any growth from the block and follow these instructions:

⮕ If you have a martha tent or an automated fruiting chamber, leave the humidity and fan running and wait about 2 weeks for new pins to begin forming.

⮕ If you are using a monotub or non-autmated fruiting chamber, open 2x daily and spray blocks generously with water. Try not to expose the blocks for too long to decrease chances of contamination.

⮕ If you don't have a monotub, martha tent, or fruiting chamber cover the block with a humidity tent made from a large plastic grocery bag with LOTS of small, quarter-sized holes. Remove the humidity tent 2x daily and spray blocks generously with water.

Be patient: It's totally normal for it to take longer for mushrooms to appear with each subsequent fruiting. However, if there's no progress after two weeks, it’s a good idea to soak your block.

Soaking your block: Take your block out of the bag and soak in a bowl of cool water. Most species only need to soak for 20 minutes. However, only soak your lion's mane block for 5-10 minutes as these blocks tend to break apart if soaked for too long. After soaking, let the block drain by leaving it cut side down for another 10 minutes or tip it around to let extra water run off. You don't want to leave standing water in your bag, so pat your block dry with a towel before placing it back in the bag.

Note: Shiitake blocks should not be placed back in the bag.

For most species, you should leave the block in the bag for the entire duration of the growing cycle. However, there are some exceptions.

⮕ Shiitake should be removed from the bag before going into the fruiting chamber.

⮕ Nameko should have most of the top of the bag cut off (leaving about 4" of plastic above the block) before going into the fruiting chamber.

Our fruiting block kits are made fromsawdust blocks that have been ammended with substrate supplements.

Cluster of brown-capped mushrooms with long, light-colored stems against a white background.

Backed by Our 100% Grow Guarantee

Every kit comes with our 100% Guarantee: You’ll get your first flush of mushrooms, or we’ll make it right. With over 350,000 happy growers, North Spore is trusted by hobbyists, chefs, and mycologists alike.

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