I've got pinning on the sides of a mycelial block in a plastic food box. Will they grow the couple of inches along the sides to the open top, or should I take it out and put it in a bag for room to grow ?

IS it better to have it open on all sides ?

  • Give us a picture Commented Mar 29, 2018 at 17:40

2 Answers 2


First off, that's a really nice looking colonization you've got there. Oysters are quite forgiving, but there are a few of things you could do to improve your success rate.

First, I wouldn't move a colonized "block" into a different container - like tub to bag. You could put a bag in the box, then later pull the bag out and puncture it, though. Typically oysters are pinned through holes in the "container" whether a bag or a box. You can actually make the holes when you inoculate your bulk substrate as long as you have the moisture content correct and aren't going to be putting it in a very dry area.

The procedure I use is to prepare bulk substrate (sawdust or straw), inoculate with spawn, then stuff into plastic bag. I then wait a few days to a week and puncture here and there with a broadhead arrow to produce + shaped openings that will stay relatively closed - preserving moisture - yet accommodate free pinning and expansion of the cluster at the substrate.

The green spots are likely trichoderma mold, though I don't actually see them in the photo. I believe you've had questions about that before.

If your bulk substrate is properly wetted at the time of inoculation, and if it is only exposed at the points of your fruiting holes, then you shouldn't need to have any additional wet wood chips for moisture.

As far as what happened when you moved it, I can only speculate - but that speculation would go like this: Mushrooms fruit once they've fully colonized to the limits of their substrate. Those limits could be the plastic bag or walls of a tub, or in nature could be the boundary with another fungal or bacterial colony. I wonder if by introducing fresh wood shavings/chips it caused the mycelium to switch out of fruiting mode and back into colonization mode.

  • Excellent thanks for the input. I was wondering whether the shavings would do what you said, delay fruiting. Anyway, I did a big change round, got a mini greenhouse, and moved it there. I got a flush that looked promising and I'm sure would have produced some good caps but a record heatwave shriveled all my junior shrooms! Not much to do about that as I haven't got a temperature controlled place. I use the greenhouse to maintain humidity but the price is it's easy to overheat. I am experimenting with covered block as well - I just put a paper bag over one and tore some holes in. Thanks! Commented May 13, 2018 at 17:33
  • On the left, carboard and wood chips with hundreds of pins. On the right the previously shown wood chip with a few thick pins and a big 'un. pasteboard.co/Hl1crAN.jpg Commented May 13, 2018 at 17:45
  • So, would restricting the light that a block receives with a holed covering make the fruit more prolific through the holes, rather than loads of pins and a couple of big fruits ? Commented May 14, 2018 at 9:30
  • It's not the light that you're interested in restricting. They pin and fruit at the location of the openings due to gas exchange - I think.
    – That Idiot
    Commented May 14, 2018 at 11:30
  • Thanks. Thing is I have two uncovered blocks, and they both develop loads of pins all over, but only one or two fruits really grow. They have plenty light and air I'm sure. I don't get the nice bunched of shrooms that I want. So far, in months of trying, after hundreds of pins, I've had one mushy big enough to go on my toast. Do they really need a breeze around them or is a half open greenhouse enough ? It may be that my humidity monitor is crap, maybe I'll try spraying more. Commented May 16, 2018 at 6:24

Well, I decided to give it some room and move into a bigger box. I think that has stimulated a lot of pinning on all sides. The substrate is cardboard, egg cartons and wood chip - some sort of hard wood. The sawdust is just to hold moisture. It also has some green bits growing. Not the kind of all over dark green mat, but little blobs of bright green.

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  • Well, they grew long and spindly, then I left the lid off for a night and they dried out and seem to be retreating. Commented Apr 12, 2018 at 12:42
  • So I covered with a black bag, put a few holes in, and put them on a window sill, and hey mushrooms! Commented Jun 12, 2018 at 11:05
  • pasteboard.co/Hpxz3Js.jpg Commented Jun 12, 2018 at 11:11

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