Sunday, September 5, 2010
The Wonderful Mesquite
I've written about the mesquite before (http://huerto-de-altamira.blogspot.com/2009/02/germination-of-honey-mesquite-prosopis.html). February, 2009, when I wrote about germinating mesquite seeds was before I bought the Berry Farm. I no longer need to germinate seeds, unless I want to introduce genes from mesquite trees in San Antonio (which is where I picked the seed pods).
Soon after posting the 2009 blog entry on the mesquite tree, I was delighted to get an email from a fellow mesquite-lover, Peter Felker. He studied mesquite trees when he was at Texas A&M University, Kingsville, and sent me several articles that confirmed my own observations that mesquite trees fix nitrogen, making it available to neighboring plants, as well as helping neighboring plants withstand droughts. Many people around here believe that mesquite trees suck water away from other plants, but the evidence I've seen is all to the contrary. My guess is that mesquite "pump" water from deep down (I've read that their roots can go up to 100 feet deep; don't know whether this is true, but I know they're very deep-rooted trees) and release it through their leaves.
Here is a photo I took yesterday of a stand of giant ragweed near a group of mesquite trees. The ragweed only grows around the mesquite trees. Outside a radius of 20 or 30 feet from the edge of the canopy, there is no more ragweed.
Ragweed has a shallow, fibrous root system, so is unable to tap deep into the soil for nutrients. Since nutrients tend to wash easily down through East Berry Farm's sandy soil, it's very likely that the mesquite trees are providing both food and water for the giant ragweed, which explains why they grow only in the vicinity of the mesquite trees.
A study done in Virginia showed that common ragweed (closely related to giant ragweed) contains more digestible dry matter than alfalfa and is almost as high in crude protein.
[See The Nutritive Value of Common Pasture Weeds and Their Relation to Livestock Nutrient Requirements
The giant ragweed produces a tremendous amount of biomass, and with its high protein (~ nitrogen) content, makes excellent mulch for the garden.
Native grasses, Coastal Bermudagrass, day lilies, canna lily, strawberries, and olive trees all grow better at the Berry Farm than similar plants not planted near mesquite trees.
Besides improving the garden soil and providing light shade, mesquite trees provide a more direct source of human food. Dr. Felker also mentioned that he had helped to set up a business in Argentina that sells flour made from mesquite pods. At the time, I had to hunt it down in a store (I found some at Central Market in San Antonio), but it can now be purchased online: Casa de Fruta. It is a delicious addition to many breads and pastries, including pancakes, bread, and pie crust.
Mesquite also provides a beautiful hard wood for furniture and building (I've seen incredibly gorgeous mesquite floors (See Texas Mesquite Wood Flooring).