(Re-posted from my original blog on Blogger). Over lunch this week we were discussing the difference between white and green asparagus. The question was whether green asparagus is the same species as the white or two different species, which is why they would be different colors.
Oh, the power of Google! I learned that white and green asparagus are the same species but it’s the way that they are grown that affects the color of the vegetable. To grow white asparagus the farmers or gardeners cover the entire shoot with dirt. Without sunlight, the asparagus stays white.
I remember learning in a Plant Physiology class at NC State that it is the magnesium that is required for the synthesis of chlorophyll, which makes plants green. The magnesium is connected to the center of the chlorophyll ring and is the element necessary to convert light into energy. In general terms, the magnesium molecule is necessary for the formation of chlorophyll, which makes plants green. Chlorophyll absorbs red and blue light, reflecting green light which is why plants look green. If you are interested in learning more, check out the website credits below, these are great resources for additional learning!
Back to the asparagus. The most abundantly grown are green in color, with white less so and considered a delicacy. White asparagus are grown mostly in Europe and South America and can be pretty hard to find in the United States. There are even purple asparagus! This is a different variety than the other two and is purple in color due to the pigment called anthocyanin.
I really like asparagus, it is probably one of my favorite vegetables. I didn’t think to plant any in our garden this year mainly due to lack of garden space. Maybe next year we will try to grow year-old asparagus crowns. This vegetable is perennial, so it comes back every year. I learned that the plants are monoecious, which means that the whole plant is either male or female. The male plants are what you want if you are looking for a more productive crop. Once established, the asparagus crop is good for 20 to 25 years! The organicgardening.com website below has some great tips for gardening asparagus, which we may try next year.
Asparagus photograph: http://www.dreamstime.com
Chlorophyll photograph: http://en.wikipedia.org/wiki/Chlorophyll