Wine cap mushrooms are not as well known as Portobello , but in my opinion their flavor and appeal is comparable, and in some cases superior.
They are meatier and grow well in outdoor beds. One of the problems with growing wine cap mushrooms outdoors , or any mushroom for that matter , is the possibility of contamination from native fungal spores, which are all too frequently toxic and potentially lethal. You must be certain in your mushroom identification before you ingest them. [ How do I tell if a Mushroom is safe to eat? ]
Once you're certain you can distinguish between your domesticated mushrooms and possible native contaminants you can propagate a patch of mushrooms outdoors. Wine Cap mushrooms will grow when soil temperature is above 50 degrees F. Late winter - to harvest in the spring. Early spring to harvest in the fall.
Choose a location that has partial shade , mushrooms like all fungi, do not like direct sunlight. A 1 1/2 to 2 inch layer of compost on top of the spores will help to keep them from drying out in the sun.
A raised bed or containers are best, if using a raised bed be sure you use bricks or a rot-resistant wood, as constant moisture will expedite the decay of any organic materials such as wood.
Fill your bed or container 6 to 8 inches deep with decaying compost and fresh organic matter such as sawdust or wood chips.
Sprinkle the spores as evenly as possible over the surface. For every 6 Sq. feet of planting surface you'll need about 1 1/2 cups of dried mushroom spores.
Sprinkle the spores onto the compost and slightly compact them in by pressing firmly on the surface - I didn't say to squash them , I just said press firmly. Sprinkle some peat moss or more compost over the surface after you've laid your spores, about 1 1/2 inches will suffice.
Regardless of the season you should always keep the bed moist and well watered. Within a month your first mushrooms should be ready to harvest. Allow some mushrooms to stay in the bed , open their caps and spread more spores to ensure future harvests.
You'll find them popping up wherever conditions are conducive to their growth. When the initial bed is exhausted and has ceased to produce, add a 1 inch layer of fresh wood chips or shredded yard leaves, add some more spore and it will produce again.
Wine cap mushrooms are wine-colored when young, they turn a yellowish-brown when mature. They are best harvested before they turn colors.