Author: Jim Downer

Dr. Downer has 34 years of experience as a horticulture and plant pathology Advisor with the University of California Cooperative Extension in Ventura County. Dr. Downer’s academic training is from California Polytechnic Univ., Pomona, (BSc. horticulture & botany, 1981; MSc. Biology, 1983;. In 1998 he earned a Ph.D. in plant pathology, from University of California, Riverside. Dr. Downer’s research is focused on mulch, soil microbiology and disease suppression in mulched soils, diseases of shade trees and cultural practices to maintain landscape plants. Dr. Downer is a member of the American Society of Horticultural Science, the American Phytopathological Society, The International Soc. of Arboriculture, and the Western Chapter of the ISA, and the International Society for Horticultural Science. Dr. Downer is an Adjunct professor at California Polytechnic University in Pomona. Dr. Downer serves on the Board of the John Britton Fund for tree Research as the chair of the research advisory committee, and currently chairs the regional conference committee for WCISA. Dr. Downer has a love of shade trees, Shinrin roku (forest bathing/walking) tree work, wood working, horses, gardening, horticulture and the study of plants and their biology.

Understanding mysteries of plant diseases: Diagnosis and Detection (Part 2 of 3 in this blog series)

Something is wrong?

Do you ever have a feeling that there is something wrong with a plant? It’s just not healthy looking, or it has not grown for awhile? As we discussed in the last blog, disease is a process–it occurs over time. When in the disease time-line you notice the process, can be quite varied. Some astute gardeners may know something is wrong before there are symptoms, others may not take notice of the process until the plant is dead.… Continue reading this article “Understanding mysteries of plant diseases: Diagnosis and Detection (Part 2 of 3 in this blog series)”

Understanding mysteries of plant diseases

(Post 1 of 3 in this blog series)

Gardeners, especially those new to gardening may find they have a “black thumb.” Plants die for no reason! “Oh well chuck it in the greenwaste recycling can and start again.” Or… “Oh I can’t grow cyclamens!… They always die in my garden for some reason.” For many gardeners it is mysterious why some plants fail to thrive or die suddenly. Plant disease processes are complicated, and it requires some knowledge of botany (anatomy and physiology), genetics, and microbiology to really understand what is happening.… Continue reading this article “Understanding mysteries of plant diseases”

Tuning up for Pruning Up–Care, Maintenance and Utilization of Hand Pruning Tools

A. J. Downer

Fall is passing into winter and the bare sticks in my deciduous fruit orchard are calling to my annual fruit tree pruning chores.  I can prune my entire orchard with very few tools: a good pair of bypass clippers, a similar set of loppers

(optional) and a high quality “razor” or “tri edge” saw.  Most hand tools require some maintenance especially the clippers and loppers.   Clippers are easily sharpened but modern saw blades can not be sharpened by gardeners.… Continue reading this article “Tuning up for Pruning Up–Care, Maintenance and Utilization of Hand Pruning Tools”