Pests and Diseases

In general, if you have plant pests and diseases, the first thing you need to do is to find out more about the plant. Learn its natural tendencies, growth habit, preferences, and weaknesses (in terms of insects and susceptibility to particular diseases). Then read diagnostic books, search on the internet, call your extension agent, contact the Master Gardeners, or visit a public garden. For more resources, look at the following tabs/pages on 1) Master Gardener, 2) Public Gardens, 3) Nurseries, and 4) Soil Tests.

Northern Virginia

One of the great, free resources available to gardeners in Northern Virginia are the plant clinics sponsored by the Virginia Cooperative Extension (VCE). If you have a gardening problem or question, you can visit the plant clinics at select farmers markets, public libraries, and special events to get answers to your questions and solutions to your dilemmas.  All are staffed by volunteer Master Gardeners who have received training from the VCE to answer general gardening questions; questions about pests, diseases, or weeds; and identify plants.

In addition to the free plant clinics, there are two other places to go for your gardening challenges if you live in Fairfax or Arlington County or the City of Alexandria. There is an Arlington VCE office at the Fairlington Community Center, 3308 S. Stafford Street, and a Fairfax VCE office at the Fairfax County Government Center, 12011 Government Center Parkway, Suite 1050 of the Pennino Building. Call the Fairlington help desk at (703) 228-6414, between 9 a.m. and noon, Monday through Friday, year round, or visit in person, or e-mail Or call the Fairfax help desk at (703) 324-8556, between 9:30 am and 12:30 pm, Monday through Friday, April through October, or visit in person, or e-mail at (hours are Tuesday and Thursday 9:30 am to 12:30 pm November through March). Other Virginia counties have similar resources, this link provides the contact information for each county’s VCE office

In Northern Virginia, regularly scheduled plant clinics are at select Fairfax County public libraries and Arlington public libraries and farmers markets. Contact them to find out where and when.


The University of Maryland Extension’s Home & Garden Information Center offers an extensive online library of lawn and garden information and a free online service to answer questions from Maryland and DC residents. Submit lawn, garden and pest questions to: Answers are provided by Maryland Certified Professional Horticulturists and University of Maryland Extension specialists.

In Montgomery County, regularly scheduled plant clinics are located at public libraries and farmers markets, including a few other places listed below. Contact them to find out where and when. The Montgomery County Master Gardeners website provides additional resources.



Weeds of the Northeast by Joseph C. Neal, Joseph M. DiTomaso, Richard H. Uva, and Antonio DiTomasso, Comstock Publishing Associates, Second Edition, 2023

Doctor Houseplant: An Indispensable Guide to Keeping your Indoor Plants Healthy and Happy by William Davidson, Cool Spring Press, 2020

Pests and Diseases by Andrew Halstead and Pippa Greenwood, DK Publishers, May 2018

Home Gardener’s Garden Pests and Diseases:  Identifying and Controlling Pests and Diseases of Ornamentals, Vegetables, and Fruits by David Squire, Creative Homeowner, 2016

What’s Wrong with My Plant (And How Do I Fix It?) (2009);What’s Wrong with my Vegetable Garden (2011); What’s Wrong with my Fruit Garden (2013), What’s Wrong with my Houseplant (2016) by David Deardorff and Kathryn Wadsworth, Timber Press

The Gardener’s Guide to Common-Sense Pest Control: Completely Revised and Updated by William Olkowski, Helga Olkowski, Sheila Daar, Taunton Press, 2013

The Practical Encyclopedia of Garden Pests and Diseases: An Illustrated Guide to Common Problems and How to Deal With Them Successfully by Andrew Mikolajski, Anness Publishing 2012

Good Bug, Bad Bug by Jessica Walliser, St. Lynn’s Press, 2011

The Organic Gardener’s Handbook of Natural Pest and Disease Control: A Complete Guide to a Healthy Garden and Yard The Earth-Friendly Way by Barbara W. Ellis, Fern Marshall Bradley, and Deborah L. Martin, Rodale Press, 2010

Rodale’s Vegetable Garden Problem Solver by Fern Marshall Bradley, Rodale Press, 2007

Better Homes & Gardens Garden Doctor Advice from the Experts, Meredith Corporation, 2005

Garden Insects of North America by Whitney Cranshaw, Princeton University Press, 2004

Reader’s Digest, Gardener’s Problem Solver, Miranda Smith, 2004

Insect, Disease and Weed ID Guide: Find-it-Fast Organic Solutions for Your Garden by Linda Gilkeson, author; Jill Jesiolowski, editor; Deborah L. Martin, editor, Rodale Press, 2001

Pests and Diseases: The Complete Guide to Preventing, Identifying, and Treating Plant Problems by Pippa Greenwood, Andrew Halstead, A.R. Chase, Daniel Gilrein, American Horticultural Society, 2000.

Weeds of the Northeast by Richard H. Uva, Joseph C. Neal, Joseph M. DiTomaso, Cornell University Press, 1997

Produced and written in January 2015, updated July 2021. Copyright Peggy Riccio and

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