How to Grow Portobello Mushrooms

The portobello mushroom is of the same species as the common button mushroom. The portobello is the mature version of the crimini button mushroom, which differs from the common button only in color. Portobellos can be grown at home and are easiest to grow if purchased in kit form. In 2009 these kits ranged in price from $30 to $50 and produce between 4 and 6 pounds of mushrooms. You can purchase the spawn and grow the mushrooms yourself in the correct medium, if available.

Things You'll Need

• Crimini mushroom spores
• Horse manure based compost, or
• Pasteurized nitrogen enriched wheat straw
• Raised bed for growing
• Black plastic sheeting
• Garden rake

Instructions

1. Fill a raised bed with horse-manure based compost to a depth of 6 inches to 12 inches. Cover with the black plastic sheeting and allow the compost to cook for one full day in the hot sun.

2. Remove the plastic and distribute the spores over the surface of the bed.

3. Rake the spores into the loose compost, covering the spores completely at a depth of at least 2 inches.

4. Water until moist and replace the black plastic.

5. Water once daily for one week, replacing the plastic after watering.

6. Remove the black plastic from the bed. Mist the bed lightly every day.

7. Watch for the first flush of mushroom to appear after about two weeks. Harvest when the mushrooms have matured to the desired size.

Tips & Warnings

• The mushrooms should continue to flush every eight to nine days for five to six weeks. The mushrooms can be harvested before maturity to be used as button mushrooms in recipes or salads. It is important that the bed be kept moist, both during incubation and the growing period as mushrooms need the water for growth and proper formation.

References

• The Mushroom Cultivator: A Practical Guide to Growing Mushrooms at Home, by Paul Stamets and J.S. Chilton, Agarikon Press, 1983

Resources

• Read this Article in Spanish
• Source of Portobello spore and kits