information:extraction
Ecology

Garlic plants are usually hardy and not affected by many pests or diseases. Garlic plants are said to repel rabbits and moles. The California Department of Food and Agriculture conducts a certification program to assure freedom from nematode and white rot disease caused by Stromatinia cepivora, two pathogens that can both destroy a crop and remain in the soil indefinitely once introduced. Garlic may also suffer from pink root, a typically non-fatal disease that stunts the roots and turns them pink or red; or leek rust, which usually appears as bright orange spots. The larvae of the leek moth attack garlic by mining into the leaves or bulbs.

Botrytis neck and bulb rot is a disease of onion, garlic, leek and shallot. Botrytis allii and Botrytis aclada cause this disease in onion and Botrytis porri causes it in garlic. According to the University of California,

Initial symptoms usually begin at the neck, where affected tissue softens, becomes water-soaked, and turns brown. In a humid atmosphere, a gray and feltlike growth (where spores are produced) appears on rotting scales, and mycelia may develop between scales. Dark-brown-to-black sclerotia (the resting bodies of the pathogen) may eventually develop in the neck or between scales.