Please will you explain the uses for Diatomaceous Earth, and the formats of delivery. I'm once again trying to prepare how to deal with those garden ...
Diatomaceous Earth #445020
Asked March 26, 2018, 4:59 PM EDT
Please will you explain the uses for Diatomaceous Earth, and the formats of delivery. I'm once again trying to prepare how to deal with those garden pests that invade. Last year I purchased praying mantis and plan on doing that again. Those within my plot and throughout my community garden that seem to be the toughest are: japanese beetle, colorado potatoe and the mexican bean beetles, the squash bug and vine borers.
Expert horticultural opinion regarding the efficacy of diatomaceous earth for insect control is mixed.
Whitney Cranshaw of Colorado State University says, "Diatomaceous earth/pyrethrins applications around the base of the plant can be an effective method to control squash bug and is a treatment allowed in Certified Organic vegetable production." However, please note, in this case the diatomaceous earth is combined with pyrethrins.
According to University of Minnesota Entomologist Jeff Hahn,
"Diatomaceous earth (tiny fossilized skeletons of ancient aquatic diatoms) is moderately effective as a slug barrier. When slugs come in contact with diatomaceous earth, it is abrasive to their skin. Diatomaceous earth is most effective when used in dry conditions and has little effect when it absorbs moisture."
The University of Minnesota and others have published bulletins that explain how to control the pests you have mentioned. These are in addition to the Colorado State University bulletin about squash bugs previously noted.
Late planting in early July is recommended to avoid vine borer damage to zucchini and other summer squash. Winter squash generally require a longer growing season so late planting may not be an option in that case.
This work is supported in part by New Technologies for Ag Extension grant no. 2020-41595-30123 from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.