Manual: Horse Mushroom Grow Kit

Manual: Horse mushroom (Agaricus arvensis)

This grow kit contains a fresh substrate for Agaricus arvensis. This species is known for its light anise smell and belongs to the same family as the common button mushroom, but grows a little slower and more robustly.

On arrival the substrate is still young and first has to colonise further before you can start growing.

After delivery: let it colonise first

  1. Leave the bag closed
    Do not open the growing bag yet. During transport the air was removed from the bag. After delivery, air comes back into the bag by itself.
  2. Put the bag in a quiet spot
    Temperature: 20-24 °C
    Dark or semi-dark
    No direct sunlight
    Not in the fridge
  3. Waiting time
    Leave the bag for another 10-14 days. Agaricus arvensis usually grows a little slower than Agaricus bisporus.

The bag is ready for the next step as soon as the substrate is almost completely white on the inside from the mycelium.

Step 1: Applying the casing layer

When the substrate has colonised enough:

  1. Carefully open the growing bag at the top
  2. Spread the supplied casing soil evenly over the substrate
  3. Thickness of the casing soil: about 2-3 cm
  4. Press the casing soil down lightly (do not compact it)

Step 2: Moistening

  • Lightly moisten the casing soil with a plant sprayer
  • The soil should feel moist, not wet
  • Avoid puddles of water

Step 3: Fruiting

  1. Put the bag in a place with:
    • Temperature: 16-20 °C
    • Normal daylight or room light
    • No direct sunlight
  2. Keep the casing soil lightly moist:
    • Spray carefully 1-2 times a day
    • Do not spray directly onto the mushrooms

After about 3-4 weeks the first young mushrooms appear.

Harvesting

  • Harvest while the cap is still largely closed
  • Carefully twist the mushroom loose
  • Do not cut or pull
  • Lightly fill the resulting hole with some casing soil

After the first harvest, one or two more harvests can follow.

Special features of Agaricus arvensis

  • Often has a clear anise smell, especially in young specimens
  • Grows bigger than Agaricus bisporus
  • Grows a little slower
  • Produces fewer, but larger mushrooms

Only use specimens that you know for certain come from this grow kit. Foraging Agaricus species in the wild requires specialist knowledge.