Common Weeds & Diseases

Overgrown blackberry patch

The links below will take you to an NCAP webpage or factsheet (PDF) with additional information about that topic. NCAP grants permission to print out and copy these articles. You may distribute as many printed/photocopied copies as you want, but they must be free to recipients.

For expert advice tailored to your pest or weed issues, check out our sliding scale Pest and Weed Management Consultation services.


Keeping bindweed out of your fields or garden is the best way to prevent problems with this weed. When dealing with field bindweed, the farmer, land manager, or home owner must recognize that there are no 'quick-fix' solutions to eliminate it. All techniques require persistence and patience. Black plastic or landscape fabric weed barriers covered with an organic mulch deprive bindweed of sunlight and have been used successfully to manage this pest, along with flame weeding, which serves the same purpose as hand-pulling or clipping.


One technique for removing unwanted berries is mowing or cutting; cut back the vines to ground level. Covering the soil after cutting or mowing can be an appropriate way to kill roots and crowns. Digging out blackberry root crowns and major side roots is another effective removal technique. Another, maybe not as practical removal technique, involves the use of goats. Goats eat blackberries readily, and seem to prefer them over other plants.


Compost tea uses a pump to inject air through a solution of compost and water to encourage a special mix of aerobic microscopic organisms to grow. These soil microbes are very beneficial in a number of ways.


If you need to control dandelions, focus on creating a strong, healthy lawn. Mow frequently and leave the grass clippings on the grass as fertilizer. If necessary, there are many nonchemical tools available to kill dandelions or remove them. And remember that dandelions can be beneficial- be willing to put up with a few dandelions in your yard!


Since the beginning of civilization, fire has been a tool for managing vegetative growth in the landscape. One source lists eleven major uses of fire by Native Americans: for hunting, crop management, improving growth and yields, fireproofing, insect collection for consumption, pest management, warfare, “economic extortion,” clearing areas for travel, felling trees, and clearing riparian areas. However, it took quite some time to figure out how to control fire for modern agricultural and home garden usage.

FLATWEED (factsheet)

Flatweed (Hypochaeris radicata), also known as hairy cat’s ear, is a low-lying perennial in the family Asteraceae. It acts as a weed in lawns, pastures and waste areas due to its ability to spread aggressively and its preference for sandy, loamy or clay soils. This guide explains the background, identification, reproduction and control techniques for flatweed.


Instead of herbicides, some people turn to goats to clear their properties of invasive weeds. Goats can knock down weeds in hard-to-reach places such as steep slopes or heavily overgrown areas where using machinery would be difficult or too damaging.


Houseplants bring nature, color, and beauty inside our homes. They're a popular way to make our indoor life more pleasant; about 75 percent of American families have plants in their homes. Occasionally these plants have problems with pests, but it's not necessary to use pesticides when this happens.

KNAPWEED (factsheet)

An imported pest from Europe, diffuse knapweed has thrived in the disturbed and dry areas that predominate at the lower elevations of the Wenatchee National Forest. It spreads rapidly because it produces a huge number of seeds and because it releases a chemical that retards the growth of other plants. There are pesticide-free ways to prevent and remove it, however. Using a strategy called “stronghold”, people can focus on gaining control of the weed in specific areas and then connecting those areas.


Lots of pesticides are used on lawns. Many people are familiar with 2,4-D, an herbicide that’s often found in "weed n feed” products and is the most commonly used lawn care pesticide. According to the U.S. Environmental Protection Agency, about 9 million pounds of 2,4-D are used on U.S. lawns every year—that’s more 2,4-D than is used on all 50 million acres of wheat grown in this country! 

LOVE YOUR LAWN (factsheet)

Forget the Weed n Feed! Start incorporating easy, ecologically-sound practices that will help your lawn thrive and outcompete weeds! Or, get started on a lawn alternative like an ecolawn, meadowscape or rain garden.


Moss develops in unhealthy lawns. To promote healthy soil and lawns, try these helpful tips. Lime, prune, and aerate your lawn, install a draining system, use a thatching rake to remove dead grass, and water deeply but infrequently.


Moss is an important part of ecosystems, but on a roof, moss growth can destroy cedar and shingled roofs. And moss control products can be harmful as they leach into the environment, and impact water quality and the food chain. Watch a short video with tips for prevention and treatment of moss on roofs, plus see our handy flowchart.


To a child a dandelion may be a cheery flower, but to his parents a dandelion may be a bane in the backyard. What makes a wildflower a weed is the damage it causes to more desirable plant species. This can be perceived aesthetic damage or damage due to increased competition for water and nutrients. Many gardeners use herbicides to get rid of these weeds. However, it is possible to manage weed problems without causing more damage to the environment by using herbicides.


Noxious weeds are non-native plants, mostly weeds of rangeland or pasture, that are classified under federal and state law as having negative impacts on agriculture. In many states, counties, and cities, control of noxious weeds is mandated by law. 


Poison oak and poison ivy provide nourishment to animals and stabilizes soil, but they also pose a serious threat. To remove the plants try digging up the roots in the late fall or cover the plants for several months. This will take away the sunlight and therefore starve the plants. 


Powdery mildew is a fungus disease of many plants. It is easily recognized by its white powdery growth on both sides of leaves, and sometimes on blossoms, fruit and stems. The first sign of infection is often white circular spots on leaves. Later the leaves often curl, and take on a distorted shape, turn yellow or brown, and may fall from the plant prematurely. This may cause the plant to weaken, and, in some cases, die.


Have you ever stood behind your lawn mower or in the lawn care aisle of your local home-improvement center in dismay? Have you ever wished that you and your neighbors could take care of your lawns in an ecologically sound way?


We should all be concerned with the amount of herbicides used for roadside vegetation management. With patience, nonchemical methods can be as, if not more, effective than herbicide use. Alternative controls like mowing and mulching have been used effectively by a number of countries and jurisdictions in the Northwest. Along with the use of barriers and hydroseeders.


Roses, the most popular perennial flower in the U.S., entice and attract many of us with their elegant, fragrant flowers. They grow well in the Pacific Northwest; spring rainfall, sunny summers, and moderate winters all help roses thrive. These same conditions, however, encourage some common diseases and roses are often considered troublesome plants that need the help of fungicides to grow well. Fortunately, by following some simple rules for planting and taking care of roses you can enjoy beautiful blooms without using pesticides. 


Designing your yard so that it doesn't encourage weeds can save you countless hours of weeding. If you have an area in your yard that seems prone to weed problems, think about redesigning and replanting it to help reduce weeds. Plant well-adapted varieties; their vigorous growth means weeds affect them less. Use headers -- wood, metal, or concrete dividers that are buried at least eight inches deep and stick up a couple of inches above the soil. Headers are useful for separating lawn areas from shrub beds, so that the grass doesn't invade. Low headers act as mow strips, allowing your mower to cut all the way to the edge of the lawn.


Whether you are creating an entire landscape design from “the ground up” or altering an existing site, planning is crucial. First determine the size of the site that needs to be prepared and which techniques you will use. When working with an established landscape, it may be best to start in a small area and then ex-pand. Site preparation has to be done before any planting. Remember, no site preparation technique, including herbicide applications, will completely eliminate weeds. Plan a landscape that will establish easily on your site, grow vigorously, and outcompete unwanted plants.


Some people like the aesthetic of tree wells in their landscaping. The tidy circle around the tree provides a nice contrast to the surrounding grass and protects exposed trees roots from damage from lawnmower blades. Here are some insights and successful weed control strategies gleaned from parks maintenance staff in Idaho, Washington, Oregon and California.


In recent years, some new herbicides have reached the market that contain vinegar, lemon juice and other plant-based ingredients. Some of these products contain both natural and synthetic components, while others contain all natural ingredients. These products can be used along fencelines, on driveways, in flowerbeds, and elsewhere, but only some may be used around fruit and vegetable plantings.


General information about managing weeds in your lawn. Herbicides kill weeds, but they don’t solve weed problems. In order to solve a weed problem, it’s necessary to change the conditions that are allowing weeds to thrive. Making these changes prevents weed problems, and provides a long-term solution.