Record: Monthly high and low, straw type and month of supply, the species windows that fit, and the species seen in the mandi.
Write the twelve months down one page of the diary. Against each, note the usual daytime high and night low where you live.
Shade the months where both stay inside 18 to 26 (oyster), 14 to 18 (button) or 28 to 35 (milky and paddy straw).
Write which straw is cheapest within 20 km and in which month it is available.
Check which species has a full crop cycle inside one of your shaded windows.
Visit the nearest mandi and note which mushrooms are sold and in which months. Do not treat today's price as next year's price.