How do you determine if an asparagus crown is a female or male?

Both our asparagus crowns and potted seedling plants are a mixture of unknown male and female plants.  Female plants can be identified by the berries that you will see in Autumn when they are mature enough to flower.  They may produce fruit quite young depending on the nutrient profile of the soil.  You can plant both seedlings and crowns at 30 cm inter...