Ultimate guide to mushroom grow kits 

Friends, enemies, witches and wizards, below is the ultimate guide to everything you need to know about growing mushrooms at home with a mushroom grow kit. This is an in depth guide. There is a lot of information here and some of it will not be relevant to you. Please use our table of contents and skip anything that you do not want to know. 

Table of contents

• Quick Start Guide
• Why Grow a grow kit?
• Mushroom Growing kit Vocabulary 
• What is a mushroom grow block?
• What is a Grow Block vs. a Monotub?
• Factors Affecting Mushroom yield 
• Grow kit Yield Expectations 
• Common Varieties of Mushrooms in Grow Blocks
• All in one grow kits with injection ports 
• Prepping your Grow Block for success
• The Perfect Mushroom Growing Environment 
• Large scale farms use the same blocks you buy
• Finding the right location for your Grow kit 
• Keeping Your Mushroom Grow Kit Humid: Essential Tips for a Thriving Harvest
• What Triggers your Mushroom Kit to start growing 
• The Lifecycle Of A Grow Block 
• Second flushes
• When and How to Harvest Your Mushrooms
• Diagnosing Grow kit Issues
• Composting your block
• Link to further resources
• Free Workshop on learning all about Mushroom Grow Kits
• Our community for growing Mushrooms

Quick Start Guide

1. Make sure there are no air pockets in your grow block. Remove any air. You can use tape or elastic bands. We need mushrooms to grow outside of the bag.
2. Clean the belly of your bag with 70% isopropyl alcohol and make a cross section 2 inch cut. 
3. Keep your bag in a well ventilated area with indirect light and high humidity. Keep your mushrooms as humid as you can. Spray your mushrooms with water several times a day, or use a humidifier, and cover with a damp towel.

Why Grow a grow kit?

1. Fun: Growing mushrooms is fun
2. Freshness: Being able to grow the most fresh mushrooms you have ever had 
3. Availability: Being able to grow mushrooms you would otherwise not be able to eat 
4. Health Benefits: Fresh mushrooms are packed with nutrients and antioxidants, and certain varieties may support cognitive function, immunity, and general well-being.
5. Educational Experience: Mushroom growing kits offer hands-on learning about the fascinating world of fungi and the crucial role mushrooms play in ecosystems.
6. Low Maintenance: Mushroom kits are often easy to care for, making them perfect for beginners or busy people who want a low-effort way to grow their own food.
7. Unique Addition to Meals: Homegrown mushrooms add a unique touch to recipes, allowing you to experiment with different textures and flavors that aren’t available in most stores.

Mushroom Growing kit Vocabulary 

These keywords are mainly used for growing from grow blocks. When we get more advanced, more vocabulary will be used. Since we are dealing with the end stage of mushroom growing, the fruiting stage and fully incubated blocks, these are the mushroom growing vocabulary that we need to know. 

• Flush: A batch of mushrooms that all mature at once, typically harvested together.
• Pins: Tiny, early-stage mushrooms that appear before the full fruiting body.
• Grow Blocks: Pre-colonized substrates that support mushroom growth.
• Substrate: The material that provides nutrients for mycelium to grow, such as masters mix, straw or sawdust.
• Inoculated: The process of introducing mushroom spores or mycelium (the vegetative part of the fungus) into a growing substrate (such as grain or substrate) to begin colonization.
• Contamination: The presence of unwanted organisms like bacteria, molds, or other fungi in the substrate or growing environment. Contamination can hinder or prevent mushroom growth and often leads to a failed crop.
• Incubation: The period during which inoculated substrate is kept in an ideal environment to allow the mycelium to fully colonize the substrate. 
• Biological Efficiency (BE): A measure of how much mushroom fruiting bodies (the mushrooms themselves) are produced relative to the dry weight of the substrate. It’s expressed as a percentage, with 100% BE meaning the mushrooms weigh as much as the dry substrate used.
• Sterilization: A process to kill all contaminants in a substrate by using high heat and pressure, typically in an autoclave or pressure cooker. This is essential for creating a clean environment where only the desired mycelium can grow.
• Master Mix: A specific blend of substrate ingredients designed to support mushroom growth. Known as the highest yield substrate. 
• Grain: Whole grains used as a nutrient-rich substrate for growing mycelium.
• Mycelium: The (generally white) root-like network of fungal threads that spread through the substrate.
• Fruiting Body: The thing we think of as a mushroom is the fruiting body but it is a small part of the whole. A mushroom is like an apple on a tree. Where the apple is only a small part of a tree. Most of the fungus lives hidden underground or within wood, soil, dung, or other materials from which the mushroom sprouts. This hidden network is called mycelium. 
• Monotub: A simple, enclosed container used for fruiting mushrooms in a controlled environment. Often used for growing magic mushrooms. 
• Spores: Spores are tiny, typically single-celled reproductive units produced by fungi, bacteria, algae, and some plants. Unlike seeds, spores do not contain stored food and are usually simpler in structure, but they can develop into a new organism when conditions are favorable. In fungi, spores are often dispersed through the air or water and are capable of withstanding harsh environmental conditions, making them highly resilient and enabling species to spread widely.

 

What is a mushroom grow block?

A mushroom grow block is a self-contained, sterile environment for cultivating mushrooms. It’s filled with substrate, grain, and mycelium. Substrate, essentially food for fungi, is sterilized or pasteurized before inoculation to prevent unwanted organisms. Once inoculated, the mycelium colonizes the substrate, turning it white if no contamination occurs. A fine filter in the bag allows the mushrooms to breathe while blocking contaminants, creating a controlled environment.

You will receive a fully incubated grow block, already colonized with mycelium and ready to fruit. At this stage, it’s resistant to contamination, so you can open it without concern.

What is a Grow Block vs. a Monotub?

A grow block and a monotub are two different methods for cultivating mushrooms. Monotubs, often used for psychedelic mushrooms, involve a plastic bin with drilled holes for airflow, filled with substrate and mushroom spawn. While grow blocks are beginner-friendly and require minimal setup—just mist and wait—monotubs allow for more customization but need more monitoring and experience. Grow blocks are pre-inoculated, compact substrate blocks that offer easy, controlled cultivation, ideal for beginners. Each method has unique advantages depending on your growing goals and skill level.

Factors Affecting Mushroom yield 

When buying a grow block, consider size and substrate for yield. "Master Mix" is the highest-yielding substrate. Many providers don’t disclose substrate type or block size, so keep these factors in mind to maximize your yield.

Grow kit Yield Expectations 

*These are very ballpark and were generated using ai 

Mushroom Type	Substrate Type	Block Weight	Yield per Flush (grams)	Total Yield (grams)	Expected Flushes
Oyster	Straw	3 lbs	150-300	450-900	2-3
Oyster	Straw	5 lbs	200-400	600-1,200	2-3
Oyster	Master's Mix	5 lbs	300-500	900-1,500	3-4
Oyster	Master's Mix	10 lbs	500-700	1,500-2,200	3-5
Lion’s Mane	Hardwood Sawdust	3 lbs	100-200	300-600	2-3
Lion’s Mane	Hardwood Sawdust	5 lbs	150-300	450-900	2-3
Lion’s Mane	Master's Mix	5 lbs	250-400	750-1,200	3-4
Lion’s Mane	Master's Mix	10 lbs	400-600	1,200-1,800	3-5
Shiitake	Enriched Sawdust	5 lbs	100-250	300-600	2
Shiitake	Enriched Sawdust	10 lbs	200-400	600-1,000	2-3

Common Varieties of Mushrooms in Grow Blocks/kits

Mushroom grow kits generally include specific types of mushrooms that are relatively easy to cultivate, have shorter growth cycles, and perform well in a home environment. Some mushrooms are commonly chosen for kits because they grow quickly and have less complicated requirements, like oyster mushrooms, which are hardy, resilient, and thrive in a range of conditions. Other popular kit mushrooms include lion’s mane, shiitake, and reishi, each of which has unique benefits and characteristics but also grows fairly reliably with minimal specialized care.

• Blue Oyster: Mild, earthy flavor with a meaty texture; may support immune health.
• Pink Oyster: Slightly seafood-like taste with a delicate texture; high in antioxidants.
• Yellow Oyster: Mild, slightly sweet flavor with a hint of nuttiness; rich in fiber and protein.
• Lion's Mane: Crab-like, savory taste; supports brain health and may improve focus.
• Chestnut: Nutty and earthy with a firm bite; contains immune-boosting polysaccharides.
• Chicken of the Woods: Mild, chicken-like flavor; a good source of fiber and vitamins.
• Reishi: Bitter, woody taste, typically used in teas; may reduce stress and support heart health.
• Cordyceps: Earthy, slightly nutty; boosts energy and enhances stamina.
• Hen of the Woods: Earthy, peppery flavor with a tender texture; may support immune health.

 

All in one grow kits with injection ports 

All in one grow kits come pre-sterilized with no mycelium. They come with grain and substrate and an injection port. You can then buy spores or liquid culture and inject the bag through the injection port. The injection port is self healing, and since you will use a sterile needle you will maintain the sterile environment within the bag. The benefit of all in one kits are you can inject any liquid culture into the bag. This is often popular with growing psychedelic mushrooms as you can legally buy magic mushrooms spores and sterilized bags. After your bag turns fully white it will be fully inoculated and you can move to the fruiting room stage. 

The Perfect Mushroom Growing Environment 

Creating an ideal environment is key to successful mushroom cultivation. Professional mushroom farmers optimize four main factors: humidity, temperature, light, and ventilation. Mushrooms thrive in humid conditions—aim for 80-90% humidity to keep them moist. Understanding how humid this is will help you when trying to keep your mushrooms humid. Above is a picture of 80-90% humidity. It is so humid you can see it.  Most varieties prefer moderate temperatures between 60–75°F (15–24°C), with indirect light, as direct sunlight can dry them out. Good airflow is essential to prevent CO₂ buildup, so a space with gentle ventilation works best. By recreating these conditions, you can cultivate healthy, flavorful mushrooms right at home.

Large scale farms use the same blocks you buy

Many mushroom farms specialize in either making grow bags or fruiting them, with larger farms frequently buying blocks wholesale rather than producing their own. These farms focus on perfecting fruiting conditions and selling mushrooms, typically without incubation rooms or labs for mushroom genetics.

Finding the right location for your Grow kit 

Setting up a mushroom grow kit at home is simple, but location is key for success. Mushrooms thrive in a controlled environment that mimics their natural habitat. Here’s what to consider when choosing the best spot.

Low Light: Mushrooms don’t need direct sunlight. Place your kit in a low-light or shaded area—indirect natural light or even a dimly lit corner is ideal. Too much sunlight can dry them out.

Stable Temperature: Most mushrooms grow best at 60–75°F (15–24°C). Avoid areas with temperature fluctuations, such as near heaters, windows, or drafty doors.

Good Ventilation: Fresh air is essential, but avoid placing the kit in direct airflow. Mushrooms release carbon dioxide, so a slightly ventilated area prevents CO₂ buildup and promotes healthy growth.

Place in a Humid Room: If possible, keep the kit in a naturally humid room, like a bathroom or basement. Bathrooms, especially if used for showers, have higher moisture levels that can benefit the kit. However, avoid placing the kit directly on cold or drafty floors, as temperature stability is also important.

Keeping Your Mushroom Grow Kit Humid: Essential Tips for a Thriving Harvest

Humidity is crucial for grow kits because it helps maintain the moisture levels in the substrate, preventing the mycelium and developing mushrooms from drying out. High humidity also supports the fruiting process, encouraging healthy mushroom growth and optimal yields.

Use a Humidity Tent: Place a clear plastic bag or humidity tent over your mushroom kit, leaving some space at the bottom for airflow. This keeps moisture in while still allowing fresh air exchange, creating a mini greenhouse effect. Make sure the plastic doesn’t touch the mushrooms directly to avoid contamination and restrict growth.

Mist Regularly: Misting is one of the easiest ways to keep your grow kit moist. Use a spray bottle with clean, non-chlorinated water and mist the inside of the tent or directly on the kit at least twice daily. Be gentle to avoid over-saturating, as too much water can lead to mold.

Add a Moisture Tray: Place a shallow tray filled with water near (but not under) the grow kit. The evaporating water will add extra humidity to the surrounding area. You can even add a sponge to the tray to increase surface area for evaporation.

Place in a Humid Room: If possible, keep the kit in a naturally humid room, like a bathroom or basement. Bathrooms, especially if used for showers, have higher moisture levels that can benefit the kit. However, avoid placing the kit directly on cold or drafty floors, as temperature stability is also important.

Use a Humidifier Nearby: Setting up a small humidifier in the room where your grow kit is placed can help maintain consistent moisture levels, especially in dry environments or during winter when indoor air tends to be dry. Adjust the humidifier to moderate levels to avoid excessive dampness, which could promote mold growth.

Cover with Damp Cloths or Towels: Drape a damp towel around (not directly on) the grow kit’s container to raise local humidity levels. Re-wet the towel as it dries out, but ensure it doesn’t get overly soaked, as excess water around the kit can lead to bacterial issues.

What Triggers Your Mushroom Kit to Start Growing

Begin by sterilizing the area where you'll cut the bag, ensuring a clean environment. On the front of the bag, make a 2-inch slit, then cross it with another 2-inch slit to form an "X." This cut allows fresh air to enter the bag, signaling the mushrooms to begin fruiting and kickstarting the growth process.

The Lifecycle Of A Grow Block

A mushroom grow block goes through several stages for a full harvest. The fruiting period begins once the block is exposed to air and humidity, signaling mushrooms to grow. Pinning follows, where tiny mushroom “pins” emerge, marking the start of growth. During the growing stage, these pins expand into full mushrooms, ready for harvesting at peak maturity. Many grow blocks offer a second harvest after a brief resting period. Once fully spent, the block can be composted, enriching your garden soil and completing its lifecycle.

Second flushes

A "second flush" in mushroom cultivation is the second cycle of mushroom growth from a single grow block, following an initial harvest. Many grow blocks can produce two or even three flushes, depending on factors like species, environmental conditions, and how well the block is maintained. Oyster mushrooms, for example, often yield multiple flushes, while shiitake might produce fewer but still benefit from rehydration and proper care. After each flush, soaking the block to restore moisture and adjusting humidity and airflow can help extend its productivity, making the most of each block.

When and How to Harvest Your Mushrooms

Harvest mushrooms when they reach full size, typically just before the caps fully open. For most types, this is when the edges of the cap start to flatten but haven’t curled up. To harvest, gently twist the mushroom at the base or cut it with a clean knife close to the substrate. Avoid pulling to prevent damage to the block, allowing for potential second flushes. Timely harvesting preserves flavor and texture, giving you the freshest mushrooms right from your grow kit.

Diagnosing Grow kit Issues

Mushroom grow kits are a fun and rewarding way to cultivate your own fungi at home, but sometimes things don’t go as planned. Here are some common issues and quick solutions:

1. No Growth or Slow Growth
   Possible Cause: Inadequate temperature or humidity.
   Solution: Ensure your kit is kept in a warm (60-75°F) and humid environment. Mist regularly or use a humidity dome.
2. Contamination
   Possible Cause: Improper sterilization or exposure to bacteria.
   Solution: Discard contaminated kits. Practice clean techniques, and avoid touching the substrate with bare hands.
3. Dry Substrate
   Possible Cause: Insufficient moisture.
   Solution: Check the moisture level of the substrate. Lightly mist if it feels dry, ensuring it's not waterlogged.
4. Mushrooms Turning Soft or Mushy
   Possible Cause: Excessive humidity or overwatering.
   Solution: Adjust ventilation to ensure proper airflow, and avoid over-wetting the substrate.

With a little patience and attention, most issues with mushroom grow kits can be resolved easily, helping you enjoy a successful harvest. 

Composting your block

Composting your spent mushroom grow block is a sustainable way to recycle organic material and enrich your soil. After the mushrooms have fully fruited, the block still contains valuable nutrients from materials like sawdust and straw, which can boost soil fertility and improve water retention. Additionally, the mycelium left in the block may continue to grow and potentially produce new mushrooms when the compost is used, offering an unexpected bonus. By composting, you reduce waste, support a healthier garden, and return beneficial microorganisms to your soil, enhancing its structure and biodiversity. Instead of tossing out the used block, composting it promotes a more eco-friendly and circular approach to gardening.

Link to further resources

• Reddit https://www.reddit.com/r/MushroomGrowers 
• Fb group https://www.facebook.com/groups/200858493769175 
• Recommended reading: Growing Gourmet and Medicinal Mushrooms - 3rd Edition by Paul Stamets (Paperback)
• Our community Whatsapp group
• Our tiktok for tips and tricks: https://www.tiktok.com/@brooklynmushroom 
• Our instagram https://www.instagram.com/bkmushroom/ 

Free Workshop on learning all about Mushroom Grow Kits

Join our upcoming free workshop on all the information you want to know about growing mushrooms from grow kits. You can get your questions answered and grow with others in our community. 

https://www.eventbrite.com/o/brooklyn-mushroom-12062090701 

Our community for growing Mushrooms

We have a Whatsapp group of mushroom growers. Please send me an email to join our group. In our community you can get help from others and learn with others and have fun being with others who love mushrooms.