Hazel

Hazel shrubs grow to about five feet tall. The typical flower catkins have an elongated shape.

The typical flower catkins of hazel consist of about 2 million pollen grains. Only after fertilization do the hazelnuts develop from them. In Europe, these are usually harvested in September/October. Due to the allergic relationship (main allergen Bet v 1), hazel pollen allergy sufferers often also react allergically to birch or alder pollen.

Pollen season

Hazel can blossom from a temperature as low as five degrees Celsius, and together with the alder, hazel is an early flowerer. The main pollen season is in the months of February to March, however, if the winter is warmer, the flowering catkins can often be seen as early as the end of December or January. The region and the corresponding weather conditions therefore have a significant influence on the flowering time.

Possible cross reactions

Foods such as apples, peanuts, walnuts, pecans, cashews, brazil nuts, pistachios, and coconuts. The development of a cross-allergy is also known as birch pollen-nut-fruit syndrome.