Layer and Fill the Tower

Building a mushroom lasagna

Now for the fun, hands-on part. We fill the bucket! We build it up in layers, just like making a lasagna. Straw, then spawn, then straw, then spawn, all the way to the top.

Start the way we always do. Wash your hands really well. This step is extra important. Clean hands keep molds out of your tower, so scrub with soap.

Layer by layer

Here is how to build your tower. Do this with your grown-up and your clean, cool straw.

1. Put a layer of damp straw in the bottom of the bucket. Push it down flat, about as thick as two fingers.

2. Sprinkle a thin layer of spawn all over the straw. Break up any lumps with your clean fingers.

3. Add another layer of straw and push it down.

4. Sprinkle more spawn.

5. Keep going, straw then spawn, until the bucket is full.

Make the very top layer straw, so the spawn is tucked safely inside.

Press and cover

Press each layer down gently as you go. You want the straw packed firm, not loose and airy. Firm packing helps the mushroom threads jump from piece to piece.

When the bucket is full, pop the lid on top. If your holes are open, a grown-up can cover them with a little tape for now. This keeps the straw damp and keeps molds out while the mushrooms grow inside.

The waiting spot

Now your tower needs to rest in a cool, dark place. A garage, a basement, or a shady cupboard is perfect. Keep it away from hot sun.

Inside, something magic is happening. The mycelium, the white web of mushroom threads, is spreading through all the straw. It eats the straw and grows and grows.

This takes about two weeks. When you peek, you will see the straw turning white and fuzzy. That white color means the mycelium is winning and filling your whole tower.

Firm layers, a cool dark rest, and lots of patience. Soon the whole bucket will be full of white threads, ready to burst with mushrooms.

When the tower is white all over, it is nearly showtime. Next, the bursting harvest!