How to Grow Oyster Mushrooms (Blue, Pink, Gold, Black Pearl & King)
Your complete oyster mushroom grow manual from the Appalachian experts at Hernshaw Farms in Charleston, West Virginia — including temperature & humidity ranges, light & CO2 control, fruiting timelines, harvesting tips, and fixes for common problems. Links included for each kit so you can start today.
Oyster Mushroom Basics
Oyster mushrooms (Pleurotus) are vigorous, beginner-friendly mushrooms that thrive in high humidity and fresh air. With a Hernshaw Farms grow kit, you’re holding a fully colonized block — simply provide the right environment and you’ll harvest in days.
- Light: Bright, indirect light or bright artificial light.
- Humidity: Prefer 85–95% RH around the fruiting window.
- Fresh air: Oysters exhale CO2; give them air exchange to avoid long stems.
- Speed: After pinning, clusters mature fast — often within 4–8 days.
Quick start (most oyster kits): Place the kit near your kitchen sink or another humid spot. Slit the bag along the whitest part or where baby pins are forming, then mist the slit 1–2× daily to keep humidity high. Do not let water pool inside the bag. Harvest before the caps fully unfurl.
Setup & Equipment (No Tent Needed)
Our kits are designed to fruit right in the bag. Choose a stable location with bright, indirect light and good airflow (avoid blasting A/C or heaters). To boost local humidity, set a small bowl of water near the slit or place the kit in a clear tote with a few air holes.
Ideal Fruiting Conditions
- Humidity: 85–95% RH near the slit during pinning; light misting 1–2× daily.
- Temperature: Most oysters thrive around 60–75°F (species notes below).
- Light: Bright, indirect light or bright artificial light (approx. 12h/day).
- Air exchange: If stems are long and caps small, increase light and fresh air.
- Timeline: Pins in ~1–2 weeks; mature clusters 4–8 days after pinning.
If your home is very dry, drape a ventilated “humidity tent” (the bag top with holes) over the kit so air can exchange while humidity stays elevated.
Species-by-Species Oyster Guides
Blue Oyster (Pleurotus ostreatus, cool-tolerant)
Classic, meaty clusters with blue-gray caps. Great for first-time growers.
- Temp: 55–70°F performs best; tolerates household temps.
- Humidity: 85–95% at fruit set; mist the slit lightly.
- Light: Bright, indirect; increase if stems elongate.
- Harvest: Just before caps fully flatten and edges lift.
- Get the Blue Oyster Grow Kit →
Pink Oyster (Pleurotus djamor, warm-loving)
Electric coral-pink petals with a seafood-like aroma. Fast fruiter in warmth.
- Temp: 70–85°F. Loves summertime kitchens and warm bathrooms.
- Humidity: Keep RH high; pinks can dry quickly.
- Light & Air: Bright light + fresh air to prevent long stems.
- Harvest: When edges are ruffled but not brittle.
- Get the Pink Oyster Grow Kit →
Gold / Yellow Oyster (Pleurotus citrinopileatus, warm-tolerant)
Sunny yellow clusters with delicate petals and nutty flavor.
- Temp: 68–80°F.
- Humidity: High — mist consistently at the slit.
- Harvest: When caps are open but still firm; handle gently.
- Get the Gold Oyster Grow Kit →
Black Pearl (Black Pearl King Oyster, hybrid)
Thick stems and broad caps; excellent for steaks and stir-fries.
- Temp: 60–72°F ideal; steady household temps work.
- Humidity: 85–95% at fruiting.
- Light & Air: Bright light; give fresh air to avoid tall, thin stems.
- Harvest: When caps widen and edges are just about to lift.
- Get the Black Pearl Kit →
King Oyster (Pleurotus eryngii) — Special Instructions
Kings prefer a different approach than most oysters. Follow these steps closely:
- Do not open the bag at first. Keep at 50–60°F in indirect light.
- When fruits reach about 2 inches tall, open across the top (like a chip bag) and begin misting 2× daily.
- Goal: Short stems with firm, meaty texture; adjust light/air to avoid stretching.
Harvest, Second Flush & Storage
- Harvest timing: Twist clusters off when caps are wide but edges haven’t fully lifted.
- Second flush: After first harvest, let the block rest and dry for ~1–2 weeks, then resume misting for another round.
- Storage: Refrigerate in a paper bag up to a week; avoid sealed plastic.
Troubleshooting (Fast Fixes)
- Long stems, tiny caps: Increase light and fresh air; avoid stagnant corners.
- Dry edges or cracked caps: Boost humidity; mist lightly more often.
- Slow to pin: Ensure bright, indirect light; keep temps in the recommended range; be patient for 1–2 weeks.
- Contamination spot: Cut it out with a flame-sterilized knife and continue fruiting.
- Damaged block from shipping: Smoosh it back together; the mycelium will repair as it recolonizes fully white.
Oyster Mushroom FAQ
Do I need to build a humidity tent?
No — most Hernshaw Farms oyster kits fruit right in the bag. If your air is very dry, drape a perforated humidity tent over the block and mist 1–2× daily.
How fast do oysters grow?
After pinning, clusters are typically ready in 4–8 days. Kings are slower and follow the special steps above.
What temperatures work best?
Most oysters like 60–75°F. Pink and gold prefer it warmer; blue and black pearl tolerate cooler rooms; king oyster likes 50–60°F initially.
Can I get multiple harvests?
Yes. Let the block rest 1–2 weeks after the first harvest, then resume misting for a second (and sometimes third) flush.
How do I know when to harvest?
Pick just before caps fully flatten and edges begin to curl upward for best texture and shelf life.
What if my house is very dry?
Increase local humidity with a nearby water bowl, a clear tote with air holes, or more frequent light misting at the slit.
These are the star of the order , great flavor and prolific producer
Only 1 of the 4 produced mushrooms before green mold formed . The one thst produced mushrooms is still going strong. All the others had yo be discarded so thry did not spread the mold to the othrrs . ( grown in 4 tier mushroom grow chamber )
My mom told me this one of the best presents she's ever received. She was so excited to check on it every day and see the growth. She got several harvests from it and says the mushrooms are delicious too. The only issue is that the instructions had suffered from some sort of printing error and some key instructions were missing as a result. But we figured it out!
I'm pretty new to mushroom growing, but I'm learning fast. I've bought two grow blocks previously from other suppliers. Both were fine, but only yielded about half a pound of mushrooms (so far, both are on their third flush now). They turned out to only be 2 pound blocks, and at the time I did not know that the maximum yield you can expect from a 2 pound block (at least for lion's mane and blue oyster) is about half the block weight, or 1 pound. It looks like I'll probably land at about 3/4 pound, and those early blocks were definitely not kept at ideal conditions so that's about as much as I could have hoped for.
Still, getting flushes that were only 2-4 ounces was disappointing to me at the time since that's only a few mouthfuls for my wife and myself!
When I found out that hernshaw farms was offering 8 pound blocks, and now knowing the math (that at ideal conditions I could expect 2 to 4 pounds over the course of all the flushes) I was entrigued. When they recently had a 20% off sale, making their "four fun guys" package a mere $16 a block (with free shipping!) I just had to bite.
I had been developing a Maker project, a mycology growing chamber with automated humidity, temperature, co2, and light level. My prior chambers had been 1 square foot. i realized I needed to build a new supersized chamber to hold 4 8-pound blocks blocks. So I ordered 1mm thick PETG sheets 2 feet by 3 feet and constructed a chamber 2 feet wide, 18 inches deep, and 12 inches tall. I doubled the humidifier output and built new LED lights to cover the entire area, then adjusted my PID algorithms to be more suitable to a larger chamber.
Well, the four blocks were even huger than I had estimated and fit in the chamber with just enough room for all the sensor units and actuator units! This was a pleasant surprise! It took several days to get the algorithms tuned to the much larger growspace, and I am still having trouble keeping the CO2 levels under 800 (recommended max for oysters is 750). I've got a larger fan on order to address this.
The blocks were in rough shape from the shipping, with large fissures in two of them. I saw some blue patches on one of the blocks, which I was initially afraid of contam, but I also knew it could just be bruising. I let all the blocks rest in the dark for 3 days to let them recover from shipping. (I was still adjusting my chamber anyway). The blue areas were engulfed by white mycelium and disappeared. All good!
After deploying the blocks in the supersized chamber, two of them started fruiting within just a few days (chocolate oyster and blue oyster). Four days later (today) the chocolate oysters look about ready to harvest and the flush is gigantic compared to what I was getting from my old 2 pound blocks. I haven't harvested yet but I'm estimating 3/4 pound right now. The blues look like they'll be ready in a few more days.
A third block, labelled "golden oyster" just started fruiting today. Surprise! It appears to me that this is really Lions Mane (I see the little white cauliflower-like heads forming quite clearly). I would have taken a star off my rating from having a block mislabeled, but since I really wanted a lion's mane anyway, I will not! This would have really confused a completely beginner though, so I would urge hernshaw farms to be more careful in their labelling.
The fourth block, labeled snow oyster, has still not fruited, although I think I see little tiny primoridia forming now. This block has really thick white "skin", which I think I have seen some people refer to as "overgrowth". I few days ago I ran a razor blade over the exposed area to break this up, and I think that stimulated the pinning. I will keep an eye on this block.
Needless to say, I am thrilled by this deal. $16 with free shipping for a block that could yield 3 to 4 pounds of mushrooms (in my area the economic value of gourmet mushrooms is about $20 a pound). Versus the other blocks (one from Amazon, one from Etsy) that were 2 pound blocks for $25 with an additional $8 for shipping for a total of $33 that will only yield probably 3/4 pound when all the flushes are done. So the score is:
Hernshaw 4 fun guys on sale: $16 total cost (per block) for at least $60 worth of mushrooms. ROI: 375%
Amazon/Etsy blocks: $33 total cost for a block for only about $15 economic value of mushrooms. ROI: 45%
Of course the biggest advantage is, I'm getting flushes that will make a hearty side dish instead of a few mouthfuls.
Bottom line: the quality of this offering is fabulous. Even when not on sale, the value is tremendous, but if you can pick up four fun guys on sale it's beyond amazing compared to other vendors. Blows the competition (at least the two I tried) away.
