Growing mushrooms in New York is about of average difficulty. Because New York has above average humidity, which makes mushroom cultivation easier than areas with lower humidity. Mushrooms require water to grow and humidity to keep their surface cells hydrated. As a fungus, mushrooms don't use photosynthesis to grow. Mushrooms grow well in dark or subdued light.
Sterilize your mushroom growing medium if you haven't bought pre-sterilized medium. Sterilize your medium by heating it in a steam pressurization and pasteurization chamber.
Seed your sterile mushroom medium with mushroom spawn. Mushroom spawn material is available from many mushroom growing supply sources.
Maintain optimal temperature and humidity for mushroom fruiting. These values will vary, depending on the type of mushrooms you are trying to grow in New York. Some varieties need higher humidity than others and may need a humidity tent to increase humidity levels.
In more humid times of the season, some varieties may actually not do as well with a humidity tent. Check the growing requirements for the variety you are growing and try to maintain humidity levels appropriate to your variety.