When to harvest oyster, shiitake and lion's mane mushrooms

TL;DR

Oysters: pick while the edges of the biggest caps still curl under. Pink oysters can go a little further, until the edges just start to curl up. The window is hours, not days.
King trumpet: pick right before the caps flatten.
Shiitake: pick when the caps are about 50 to 75 % open, with the rim still rolled under. A flat cap is past its best.
Lion's mane: pick when the spines are about 0.6 to 1.3 cm (¼ to ½ inch) long, before they yellow.
Maitake: pick before the fronds droop or curl downward and before white spores fall.
Late costs you shelf life, texture and, for oysters especially, a room full of spores.

My notes on one of our pink oyster grows end with "waited too long to harvest but got sweet timelapse". The upside of waiting too long is that I have photos of it. We've had a camera on 12 of our grows this year, so I went back through six of them and pulled frames from the same block, taken from the same angle, at the moments the guides call too early, just right and too late.

Below are the signs that university guides and mushroom suppliers say to look for, each linked to its source, next to photos from our own fruiting chamber. Where the sources disagree, I say so. Each photo is labelled with its fruiting day: days since that block went into fruiting conditions, counting that day as day 1. Colonization time isn't included, since it varies far more from block to block than fruiting does. To see the full timelapses these frames come from, follow us on Instagram, @demeter.mycolabs.

When are mushrooms ready to harvest?

For most cap-and-stem mushrooms, when the cap has opened enough to show its gills but the edge is still curled under. That's the moment before the cap flattens, the edge turns up and the spores start falling in earnest. Lion's mane and maitake don't have caps like that, so they get their own cues below.

When to harvest, at a glance. The cues growers use, how fast each went from right to late in our photos, and how fast the spores in our chamber's air doubled once each one started shedding.

Mushroom	Pick when	Too late looks like	How fast right turns to late	Airborne spores doubled every (our sensor)
Blue oyster	Biggest caps start to flatten, edge still curled under	Flat or upturned caps, white spore dust	Hours	about 5-6 h
Pink oyster	Caps flat or slightly cupped, edges just starting to curl up	Pink dust everywhere, colour fading to creamy pink	Hours	4-9 h
King trumpet	Right before the caps flatten	Cap flat or turned up	About a day	11-12 h
Shiitake	Cap about 50 to 75 % open, rim still rolled under	Cap fully open and flat	Hours to half a day	4-9 h
Lion's mane	Spines 0.6 to 1.3 cm (¼ to ½ in), still white	Long spines, yellowing, mushy	Days	roughly a day
Maitake	Fronds open and spread, before they droop	Fronds drooping, white spores, soft and fishy	A day or more	about 13 h

Sources: GroCycle, North Spore, Ohio State, Mississippi State and Chen, Stamets et al., Maitake at a Glance; details under each mushroom. The last column is ours: once the mushrooms started shedding, how often the spores in our chamber's air doubled (more on that below).

When should you harvest oyster mushrooms?

Right before the caps flatten out, while the edge is still a little curved under (North Spore). For blue oyster, GroCycle watches the biggest caps in the cluster: once their edges start to uncurl and flatten, it's time, usually 6 to 10 days after pins appear (GroCycle).

Three photos of the same blue oyster block from the same angle, labelled too early, just right and too late. Too early, fruiting day 6 at 11:55 am: a dense tangle of small grey-blue funnels on long white stems. Just right, fruiting day 6 at 6:35 pm: the same cluster with bigger caps whose edges are still rolled under. Too late, fruiting day 7 at 3:38 pm: the top cap has spread into a wide, flat white plate with a wavy edge, and the caps below are flattening. Callouts point to the top cap's edge still rolled under on the just-right frame, and to the same cap gone flat with a waving edge on the too-late one. — Blue oyster went from too early to just right in under 7 hours. By the next morning the top cap was flat, and by the afternoon its edge was waving. That's what GroCycle means when it says the gap between too early and too late is often only a few hours.

Oysters move fast. North Spore says mushrooms can sometimes double in size in a day, and GroCycle puts the gap between too early and too late at "often only a few hours". Our blue oyster went from small funnels to full caps with rolled edges in under 7 hours, and from there to flat plates by the next morning.

Pink oysters run later. GroCycle's cue for pinks is caps that are flat or slightly cupped, with the edges just beginning to curl up, as little as 4 to 5 days after pinning (GroCycle). In our grows, pink caps were thin and fan-shaped almost from the start, so a rolled-under edge is never as obvious as on a blue.

Three photos of the same pink oyster cluster from the same angle, labelled too early, just right and too late. Too early, fruiting day 5: a small, tight cluster of bright salmon-pink caps. Just right, fruiting day 6 at 7:12 pm: a full spray of open salmon-pink fans with their gills showing and edges just starting to lift. Too late, fruiting day 7 at 1:14 pm: a bigger, paler spray with creamy-pink fans whose edges have turned up and gone wavy. Callouts point to the edges just lifting on the just-right frame, and to the turned-up edges and fading colour on the too-late one. — About 18 hours separate just right from too late, and it was already turning by 4 am, when the biggest cap's edge had curled up and the colour had started to fade. Watch the colour as much as the shape: past its moment, pink oyster goes from salmon to a creamy pink. This is the grow where my notes say I waited too long.

Too late, the colour fades to a creamy pink, and pinks shed more spores than any other oyster: "your entire grow room will be covered in pink spores" (GroCycle).

When should you harvest king trumpet?

Right before the caps flatten out, says North Spore (North Spore — affiliate link: we may earn a commission at no extra cost to you). GroCycle says any time before the caps flatten (GroCycle). Both draw the line at a flat cap. Neither says how long that takes; in our photos below it was about 21 hours. Once our king trumpets started shedding, the spores in the air doubled about every 11 to 12 hours, over two flushes of one block, against 4 to 9 for oysters. (Black pearl king, sold as a king oyster, doubled about every 6 hours, closer to the oysters, in our one grow.)

Three photos of the same king trumpet block from the same angle, labelled too early, just right and too late. Too early, fruiting day 12 at 11:42 pm: small brown caps on short, thin stems. Just right, fruiting day 13 at 6:35 pm: thick white stems with round caps still domed. Too late, fruiting day 14 at 3:28 pm: the tallest mushroom's cap has flared upward like a trumpet bell, with its gills showing from the side. Callouts point to the domed cap on the just-right frame and the flared cap on the too-late one. — About 19 hours from too early to just right, and 21 more to too late. We picked this flush the next morning, later still.

With king trumpet the stem is the crop, so picking too early costs the most. Our first flush shows the whole window: the stems fattened for most of a day, then the biggest cap flared open within the next.

When should you harvest shiitake?

When the cap is about 50 to 75 % open and the rim is still rolled under. The sources don't quite agree on the number: Ohio State says 50 to 75 % (OSU), Mississippi State 75 % (MSU) and GroCycle 80 % of the gills showing (GroCycle). They all agree on the curled rim. All four are guides for shiitake grown on logs; ours grew on a block. Cornell's version is the easiest to remember: gills visible, edge "slightly curled under, but not tightly so" (Cornell).

Three photos of the same shiitake block from the same angle, labelled too early, just right and too late. Too early, fruiting day 6: small brown caps, rounded and tightly closed, dotted across the block. Just right, fruiting day 8: larger caps, opened about three quarters of the way, rims still curled under. Too late, fruiting day 9: wide, flat, pale caps with ragged, upturned edges crowding the top of the block. Callouts point to rims still curled under on the just-right frame, and to flat caps with split edges on the too-late one. — The caps were flat by that evening, about 10 hours after just right. This frame is the next afternoon, and the edges have split. Ohio State links fully open caps to shorter shelf life, a longer wait for the next flush and more pests.

Shiitake is slower than oyster but not by much: Mississippi State says one can go from a bump to fist size in three days. A cap whose edge has flattened out is slightly over-ripe but still edible, Cornell says, and many growers dry those. For log-grown shiitake, Ohio State lists the costs of picking fully open caps: shorter shelf life, a longer delay before the next flush, and more pest problems.

When should you harvest lion's mane?

When the spines are about 0.6 to 1.3 cm (¼ to ½ inch) long and it's still white. North Spore picks "when teeth are ¼-½” long before any yellowing" (North Spore); GroCycle says it's usually ready four to seven days after pinning, and that many growers pick when the spines are about 0.6 cm (¼ inch) (GroCycle).

Three photos of the same lion's mane from the same angle against a dark chamber, labelled too early, just right and too late. Too early, fruiting day 11: a lumpy white cushion, mostly smooth, with fuzz just starting on the left. Just right, fruiting day 12: the same mushroom covered in short, dense white spines. Too late, fruiting day 20: much longer spines hanging down like icicles, with a faint yellow tinge at the top right. Callouts point to short white spines on the just-right frame, and to long spines with yellow tips on the too-late one. — Lion's mane is forgiving: days, not hours. The last frame is past it, with long spines and the first yellowing at the top right. Yellowing can also come from air that's too dry, so check the humidity before you blame age.

Lion's mane gives you days rather than hours. Too late, the spines get long, the top yellows or browns, and it goes mushy. GroCycle's kit page is more relaxed than North Spore: it counts a little yellowing on top or white spore dust underneath among its signs that it's ready, and says to pick once you see two of them (GroCycle). One catch: lion's mane also turns a dry, yellowish brown when the air is too dry, so yellowing alone doesn't always mean it's old. Too wet looks different: darker orange-brown patches that look wet, where water sat on it and it started to rot. The same rot sets in if you leave it long after it's mature. Either way, GroCycle says it's no longer edible and should be composted (GroCycle).

When should you harvest maitake?

Before the fronds droop or curl downward, and before the white spores fall (Chen, Stamets et al.). The cluster starts out as dark, tight knobs and opens into overlapping grey-brown fronds, getting lighter as it matures. GroCycle's cue is the same one as for oysters: caps (the fronds) open, edges still slightly curled under, before the spores drop (GroCycle).

Three photos of the same maitake from the same angle, labelled too early, just right and too late. Too early, fruiting day 4: tight, dark brown knobs like little brains. Just right, fruiting day 8: a mass of open, ruffled grey-brown fronds with darker edges. Too late, fruiting day 14: the fronds have gone pale cream, thin and flattened. Callouts point to open, firm fronds with dark edges on the just-right frame, and to pale, thin fronds on the too-late one. — Maitake is slow: four days from knobs to open fronds, and another six before this frame, by which point the fronds had paled and thinned, and our air sensor says it was shedding. Chen, Stamets et al. say the colour lightens as maitake matures, so pale alone isn't the cue; drooping fronds and spores are.

No source puts a number on the window. Ours, from the air: once the maitake started shedding, the spores doubled about every 13 hours, slower than oysters and faster than lion's mane. It started shedding about a day after the just-right frame above. Left too long, Chen and colleagues write, a ripe cluster can soften and give off a "foul fishy smell".

How do you pick each mushroom?

Take clusters whole, and handle the caps as little as you can.

How to pick, by mushroom.

Mushroom	Twist or cut	Notes
Blue oyster	Twist the whole cluster off at the base, or cut	North Spore, GroCycle
Pink oyster	Cut the whole cluster with a sharp knife	Twisting can damage the mycelium and let contamination in (GroCycle)
King trumpet	Twist off at the base	Gently, so you don't damage the mycelium (GroCycle)
Shiitake	Twist, or cut close to the block	Ohio State does either; GroCycle prefers cutting. Into the fridge within an hour (University of Kentucky)
Lion's mane	Reach fully around it and twist	North Spore
Maitake	Cut the base with a knife, or twist	Sources split: Chen, Stamets et al. cut, GroCycle twists. Support the weight; big clusters are fragile

Why does harvesting late matter?

It keeps worse, it eats worse, and the spores go everywhere.

Shelf life. Flattened oysters and fully open shiitake keep worse (North Spore, Ohio State).
Texture and flavour. Younger mushrooms usually have better flavour and texture (GroCycle).
Spores. Oyster spores, and king trumpet's, can cause a lung allergy (hypersensitivity pneumonitis) in growers who breathe high concentrations of them over and over, though it's rare (Satoh & Yamada 2022). Breathing problems among oyster workers led the Dutch Ministry of Agriculture to commission a sporeless strain around the turn of the century (Baars et al. 2026). Picking on time limits the spores; if you grow oysters indoors, consider a mask at harvest.

How do you keep track of when to pick?

Check twice a day once the first caps or spines appear, and more often for oysters. Photos help more than memory: one from the same spot each morning and evening makes "it was bigger yesterday" easy to check, and it's how I put this post together.

In Hypha, add those photos to the block's photo journal and log each flush's harvest. The block's Grow Summary then shows its days, total wet harvest and flush count, so next time you know roughly when to start watching.

What did our Hypha Aeris sensor see?

Our chamber has a Hypha Aeris (closed beta, not for sale yet) on it, and it picks up spores in the air as caps open (how that works). Two things stood out. The oysters and shiitake were already shedding at "just right", so they drop spores while they still look perfect to pick. And once shedding started, the spores in the air doubled every 4 to 9 hours for oysters and shiitake, 11 to 13 for king trumpet and maitake, and roughly a day for lion's mane. That's how fast the spore load builds, not how fast a mushroom looks over-ripe. It's one chamber and one or two grows per species, so treat it as a rough guide.

If you have a harvest-day photo series of your own, send it to team@demetermycolabs.com. I read all of it.

As for that pink oyster grow: I did wait too long. The timelapse was worth it.

— Sharon

When to harvest mushrooms: too early, just right and too late, from our timelapses