Prohibited to AZ
(Corylus species) Filberts are easy to grow and very productive! They are by far the most important nut crop grown commercially in the Pacific Northwest. This small tree prefers a cool, wet climate. Filberts flower in mid-winter. The abundant male catkins make a showy display. Humid, windy weather is ideal for distributing pollen to the tiny red female flowers. By the end of August nuts are ripe. They drop in September.