While native bees, including mason bees are “always a good thing,” Gardner says, it is important to order the species that’s right for your geographic area. The mason bee (Osmia lignaria), he told us, has two subspecies: Osmia lignaria lignaria and Osmia lignaria propinqua. "Lignaria lives east of the Rockies and propinqua lives west, and introducing them outside their native range should be avoided," Joel advises. Otherwise, you run the risk of spreading outside pests or diseases to local bee populations.
Unfortunately, this information is not widely known and the willy-nilly nationwide shipping of both bee species is ongoing. Gardeners who want to buy mason bees need to know that it’s important to order from reputable sellers that ship bees according to zip code.
Worm Compost and Disease Suppression Vermicompost has long been touted as being good for attracting more earthworms, increasing nutrient availability in the soil, and improving soil structure and water-holding capacity. Those things appear to be true. However, reports that vermicompost can do a whole lot more than that are often greatly exaggerated.
That said, new research from Cornell University suggests, that vermicompost may be helpful in preventing Pythium aphanidermatum, a pathogen that plagues greenhouse growers by causing seedlings to damp off, as well as root and stem rot. The article, which was published in the in the December 21 st online issue of the Cornell Chronicle, explains how Eric Carr, a master’s student working with Professor Eric Nelson in the Department of Plant Pathology and Plant-Microbe Biology, is studying vermicomposts’ ability to suppress the pathogen.
At the same time, Ph.D. student Allison Jack has built on Nelson’s previous research to show that “beneficial microbes in vermicompost can colonize a seed’s surface and protect it from infection by releasing a substance that interferes with the chemical signaling between the host and the pathogen.” The article is an interesting read, but we like that it also makes clear that research on the benefits of vermicompost and other organic waste products and resources is challenging and ongoing. While studies have shown composts can suppress disease, there remains much to be learned about which microbes suppress various diseases and how they go about doing it.
Jeff Gillman is an associate professor of horticulture at the University of Minnesota. Visit him at www.gardenprofessors.com. Meleah Maynard is a journalist, garden writer and master gardener. Visit her at www.everydaygardener.com.