Pearl Oyster Mushroom Fruiting Block | 5 lbs.
$25.00
Pearl Oyster mushrooms are the most forgiving variety you can grow — robust, contamination-resistant, and reliable producers across multiple flushes. This block ships fully colonized and ready to fruit. Cut the bag, maintain the right environment, and pins will appear within days. The block is healthy and ready. Your environment is the variable that determines everything from here.
Quantity
What’s in the Box
✓ One 5 lb fully colonized fruiting block
✓ Hardwood sawdust substrate, fully run with mycelium and ready to fruit
✓ Care card included
Setting Up Your Block
Growing mushrooms is genuinely rewarding — and a little different from anything else you’ve grown before. Unlike plants, mushrooms don’t need soil, sunlight, or fertilizer. What they do need is the right atmosphere: the right temperature, consistent humidity, and fresh air moving through their space. Get those three things right and your block will do the rest on its own.
Temperature: 65–75°F
Humidity: Aim for 90–95% while pins are forming. Once you have a good cluster developing, ease back to 80–85% — this actually improves mushroom density and quality.
Fresh air: Mushrooms need air exchange to know which way to grow. Gentle airflow — not a draft, just movement — makes a real difference. A simple humidity tent with small ventilation holes works well.
Light: Indirect light 12–14 hours a day. A windowsill out of direct sun, or a grow light on a timer, is all you need.
Not ready to start yet? Refrigerate the block and keep it dark — light triggers fruiting. It will hold for up to 3 months.
Growing Outdoors — More Ways Than You Might Think
Outdoor growing is one of the most rewarding things you can do with a fruiting block. Nature handles the humidity, temperature swings trigger pinning naturally, and blocks grown outdoors last much longer. We had a block from last season that is still producing flushes.
Method 1: Direct outdoor fruiting
Cut your bag, place the block in a shaded spot protected from direct rain. Mist if conditions are dry.
Method 2: In-ground burial
Remove the bag and bury the block in a shaded garden bed with the top surface at or just below grade. The soil retains moisture and moderates temperature. Produces flushes far longer than any indoor setup.
Method 3: Garden bed integration
Break up your colonized block and layer it through hardwood woodchips in a shaded area. The mycelium colonizes the bed and fruits intermittently for years.
Method 4: Using your block as spawn
Break the block apart and use it to inoculate straw bales, log piles, or woodchip beds. One 5 lb block can seed a surprisingly large outdoor area.
Seasonality: Pearl Oyster thrives in Virginia’s spring — chilly mornings, wet air, temperatures in the 60s. Set your block out in late March or April and conditions will do most of the work.
What to Expect — Week by Week
Day 1–2: Score an X across the top of the bag. Mist the exposed surface and place in its spot. Nothing will look different yet.
Day 3–5: Small white dots appear at the cut — primordia, the first stage of your mushrooms. Your environment is working. Maintain humidity and don’t disturb the block.
Day 5–10: Pins elongate into clusters. Growth is fast — some mornings you’ll see visible change from the night before. Keep humidity consistent.
Day 10–14: Harvest just before caps fully flatten and edges curl upward. Best when caps are still slightly cupped. Cut at the base — don’t pull.
Second and third flush: Remove remaining stem material, rehydrate with a light mist, return to your spot. Most blocks produce 2–3 flushes. Outdoor blocks often go longer.