Tips for grow block success ♡
Keep it clean
Always handle your block with clean hands and use clean cutting tools. Be sure to grow on a waterproof surface in an area that can take up to 2 weeks elevated humidity. The kitchen counter or a clear plastic tote without a lid can be good choices.
Check for pests and mold. Avoid fruiting mushrooms in areas where these are a problem. As the block nears the end of its productive life, these issues are more likely to develop. Visit our page on reusing your block or add to compost.
Give it light
Place your block where it will receive some light, but not direct sun. All our species grow naturally in filtered forest light. Incandescent light including grow lights work well.
Wait, don't mushrooms need darkness? We are often asked about growing in the dark. Darkness may cause elongated, pale, unhealthy fruits in all of our species except king oysters. Like white button mushrooms, kings are grown in dim lighting to achieve a preferred shape and color.
Research shows that mushrooms grown in UV light contain vitamin D2. You can let your mushrooms spend time outside in dappled shade before harvesting to get this benefit. You can fruit your block entirely outdoors, but the risk of pests increases. Outdoor light darkens the color of mushroom caps like a suntan. Protect growing mushrooms from drying out in sun and wind. Monitor outdoor blocks frequently for pests.
Create humidity
Prepare a clean spray bottle with plain tap or filtered water. Don't spray your block with anything you wouldn't eat!
Mist the surface of the plastic bag 2 to 5 times per day depending on your home's humidity & airflow. Try to ensure there are droplets present most of the time, especially in early growth stages. Protect blocks from heat sources like radiators and wood stoves.
Water droplets on plastic evaporate to create a humid microclimate. There is no need to water the block or the mushrooms themselves, everything they need to "drink" is in the bag. Our goal is to water the air!
Timing is everything. Mushrooms require the highest humidity immediately after cutting the bag while new baby mushrooms (aka pins) are developing. Their needs decrease a bit as they mature, and lowering the moisture a bit more just before harvest can slightly increase shelf life.
Let It Breathe
Grow in regular room air. Mushrooms inhale oxygen and exhale carbon dioxide like animals do. Don't keep them where this will be restricted. You can use totes or bags to increase humidity, but make sure at least one side of your setup is fully open to air.
Mind the breeze. Too much wind can dry out your block or your harvest. Do not grow in front of fans, vents, or breezy open windows.
Step by Step Grow Block Guide
Why do we love them?
Grow blocks bring the freshest possible harvest to your table and help teach us about how mushrooms grow and develop. They give us an opportunity to enjoy fresh mushrooms year round at home, can be reused until they cease to fruit, and make a great additive to compost when spent.
Grow blocks require daily attention and proper conditions to thrive, especially while mushrooms are actively growing.
Side fruiting species: Pearl, pink, & phoenix oysters, lion's mane
Top fruiting species: Pioppino, king oyster
Just getting started? Check out our Grow Blocks 101 video and tips here!
Side Fruiting Grow Block Instructions -
1. Cut
3. Watch
2. Mist
Cut a line across the bag and into the block with a clean sharp blade. Wrap the upper portion of the bag around the block, removing any air. Tape to secure if you wish.
If there are mushroom pins in the bag already, carefully use a sharp blade to cut the plastic and let them out. Find the strongest clusters. They may not all make it and that's OK.
2. Mist
3. Watch
2. Mist
Using your spray bottle, mist the entire plastic bag to keep humidity high. Continue to mist 2-5x daily. Do not let the block fully dry right after cutting to ensure pinning and in the first few days of development.
Continue misting daily when dry or as needed until harvest. Alternately, run a freshly cleaned home humidifier beside your block.
3. Watch
3. Watch
4. Harvest
Monitor your developing mushrooms for slow growth, shiny or cracked caps, elongated stems, or other problems. DO NOT restrict oxygen with closed bags or totes. Grow at room temperature.
Some oyster strains are faster to pin and grow. They will pin 2 days to 2 weeks from cutting, and average between 4 and 8 days until harvest.
4. Harvest
4. Harvest
4. Harvest
Oyster mushrooms have the longest shelf life when harvested young. We like to maximize freshness and size by picking when the very first cap in the cluster unfurls its rolled edge. After this point spores release (can be messy!) and freshness decreases quickly.
Gently wiggle and lift mushroom clusters away from the block. Use a sharp knife or shears to trim and remove any substrate.
5. Reuse
4. Harvest
5. Reuse
With clean hands or gloves, remove any undeveloped pins, loose mycelium, and remnants of stem from the bag. Seal any cuts with tape and return the bag to its original shape, with the filter patch open to the air. Repeat steps 1-4 for additional harvests until the block ceases fruiting or develops contamination.
Check out tips for using spent blocks in the garden or yard here.
Top Fruiting Grow Block Instructions
Step1: Watch
Step1: Watch
Watch your block for full colonization. Store at room temperature in dim light and wait for the block to turn completely white. Apply the provided rubber band 1/4 way from the top of the block to help prevent side fruiting.
Step 2: Cut
Step1: Watch
Snip a corner open at the top of the bag to introduce oxygen. Use this opening to watch the top of the block for pin formation.
Step 3: Watch (again)
As pins grow inside the bag, monitor through the opening. Handle with care as baby mushrooms are brittle can damage easily if knocked or dropped. Watch for pins to become large enough to need a little more space.
Step 4: Cut (again) and Mist
Carefully make a slit down the side of the bag in 1 or 2 places, allowing the mushrooms more room to grow and expand. Using your clean misting bottle, mist the inside and outside of the plastic grow bag for evporative humidity whenever dry.
Step 5: Harvest
Most top fruiting species pop off the block easily. Handle gently to ensure mushrooms don't come off too early. The mushrooms are ready for harvest once they reach full size but before caps spread out completely.
Step 6: Reuse
Using clean hands or gloves, remove undeveloped pins, loose mycelium, and any stem remnants. Seal up all cuts with tape and repeat steps 1-5 until the block stops producing or shows signs of contamination.