Green and white asparagus are usually grown in separate areas and by different producers. Unlike white asparagus whose principal requirement is a light soil type, green asparagus requires a certain number of particular climatic conditions, which greatly limits where it can be grown. The continental-Mediterranean climate proves ideal: winters cold enough to interrupt the asparagus's growth, and springs with cool nights and mild daytime temperatures which permit the asparagus to grow only during the day without developing the spear in order to extend the harvest period.