There are some things every gardener hates -- weeds, diseases and pests. Learn how to recognize a problem, diagnose it, and where to go for help. Also, watch for organic and inorganic solutions to common problems.
Featured Expert: Dr. Brad Geary, professor of plant and animal sciences at Brigham Young University.
Featured Expert: Adrian Hinton is a Utah State University Extension Agent. Utah County residents can contact him at adrianh@ext.usu.edu.
If you live outside Utah County contact your local extension agent
Featured Expert:
Pat Fugal is a Utah State University Extension Agent. Utah County residents can contact her at bettyd@ext.usu.edu.
If you live outside Utah County contact your local extension agent.
Special Guest: Cecilia Fisher is an avid home gardener. Cecilia has been gardening for a few years. She grows vegetables, fruits and flowers.
Click on a topic below to view additional information.
Weeds
Weeds are unwanted plants in gardens that reduce available moisture, nutrients, sunlight and growing space needed by crop plants.
If you're growing plants from seed, you might want to know what weed seedlings look like, so you can remove them from your plant pots, seed trays or nursery bed.
This Weed Photo Gallery includes many, but not all, weed species commonly found in California farms and landscapes. Many of these weeds are common across the country.
It is a good idea to know what the plants you are growing look like when they are young. Sometimes they look a lot different than mature plants. There may be a picture of the seedling on the seed packet, which can be helpful for identification.
Be sure to mark what you have planted and where. This will help you, especially at the beginning of the season when the garden is young.
If you are in doubt whether something is a weed or seedling you have planted, let it grow a little longer and it will be easier to tell.
Accurate weed identification is the first step in a successful weed control program. Various weed species respond differently to different methods of control. This site helps you identify plant characteristics to determine what it is.
Weeds are simply plants which are growing in the wrong place. They are usually the native plants which are best adapted to the environment where they grow; sometimes they have been introduced in the past for culinary, medicinal or decorative purposes.
There have been many solutions to the weed problem over the centuries. If weeds are not controlled they take up space, block sunlight, overwhelm and choke out other plants.
Annual weeds grow shoots, leaves, flowers, set seed, and die in less than a year.
Weeds inhibit the desirable plants you have in your garden. They germinate and grow quickly allowing them to get to the nutrients much quicker than your desirable plants.
Most perennial weeds, produce spreading roots, rhizomes or tubers, and live for several years.
Perennial weed roots can grow as deep as 8 feet.
Large vegetable plants shade the ground and suppress weed growth.
Become familiar with your desirable plants so you can determine which seedlings are weeds.
Weed Management Methods
You can control most weeds and prevent them from becoming serious problems in the garden. Methods of control include hand pulling, cultivation, mulching, and use of chemicals.
Garden weeds are hard to control because they grow rapidly, produce vast numbers of seeds, and spread aggressively by vegetative structures and/or seeds. There are several methods that should be used in a combined, coordinated effort to control weeds. They include cultural, mechanical and chemical methods.
In order to develop strategies to outwit weeds, we need to learn what weeds are and how they grow. This site offers helpful information about how to accomplish this.
Mechanical Weed Control
Mechanical weed control consists principally of mowing, plowing, tilling, hoeing and hand pulling.
When cultivating weeds make sure you get all of the plant - especially the roots.
Cultivation of perennial weeds may initially create a larger problem. Cultivation breaks perennial weeds and their root systems into smaller pieces which grow into entire plants.
If hand pulling weeds try to pull them when they are young. This helps in two ways: First, they are easier to pull because the roots are small and won't break off as easily. Second, if you let them mature they drop seeds which will only multiply the problem.
Equipment
There are many different kinds of tools to help with weeding, they are all effective. Consider your preference, and use what you are most comfortable with and what works best for you and your garden.
Herbicides, when used in moderation and according to label directions can successfully help control weeds. Unfortunately, many home owners rely exclusively on herbicides and this, itself, creates problems during hot summer days.
Pre-emergent are usually used early in the season when seeds are germinating. You could use a pre-emergent herbicide to keep dandelion seeds from germinating.
Pre-emergence herbicides, by definition, are herbicides that are applied prior to weed seed germination. Control of weeds using pre-emergence herbicides is most successful when the correct herbicide is applied in the correct manner to a weed-free growing medium prior to weed seed germination.
Post-emergent herbicides work on plants that already have leaves. You would need a post-emergent to kill existing plants. Post-emergent herbicides will be most effective when applied to actively growing plants.
Best time to spray is when the weeds are young. This is when they are killed the easiest and they soak up the chemicals better.
Undiluted white household vinegar (5% acetic acid) will also kill weeds when applied during the first 2 weeks of life.
Some herbicides are selective and some are nonselective. Roundup is a nonselective herbicide; it will kill anything you spray it on. Weed-B-Gone is an example of a selective herbicides it will only kill broadleaf plants.
Make sure to follow the label for use and safety.
Be careful not to touch the chemicals with your bare hand, because you can absorb them through your skin.
A pre-emergent herbicide will last 3-4 months after it has been applied.
To kill difficult weeds, place a cardboard box without a top or bottom over the weed and spray it.
Use a hand sprayer to spot spray.
Most post-emergent herbicides will last 2- 3 weeks.
Some weed species may require a combination of 2 or more herbicides to be controlled.
Protect yourself when you are spraying by wearing rubber boots, eye protection, and protective clothing.
Herbicides are best applied in the morning of a calm day, and temperatures should be between 60 - 85 degrees F.
Whatever you decide to do, just be consistent!
If you can't keep up with weeding or spraying, at least pull of the flowers or seed heads to reduce seed production.
Look up information about pests in a book or send them into the extension service to identify them. There are many web sites that provide pictures to help identify pests. Here is a site where you can look up pests that affect different plants.
There are many beneficial insects. They are sometimes called natural enemies. These are organisms that kill, decrease the reproductive potential or otherwise reduce the numbers of another organism.
Some examples of natural enemies are wasps, ladybugs, and mantis. They look like pests but they are great predators and eat many of the insects that attack our crops.
Treatment
This site contains a list of insects you can obtain more information about by clicking on the insect. You will find identification photos, management, and prevention tips.
Organic
Aphids are probably the most recognized garden insect in existence. More than 4000 species have been described, and it can almost be said that there is an aphid species for every house and garden. This site offers tips on organic control measures for aphids.
Insect control is one of the biggest problems that all gardeners have to deal with. Let's face it, there are thousands of insects in the garden, and some of them like to eat your vegetables. This site offers tips on how to control insects organically.
Insecticides
The use of horticultural oils, soaps, and Bt's (Bacillus thuringiensis insecticides) are relatively nontoxic to the user, are relatively safe to beneficial insects in the landscape. They have been considered safer insecticides for the garden.
Insecticides are usually necessary for the protection of plants. Since these materials may be hazardous to man and his environment, it is essential that we read the label and follow directions. Always think about alternate measures of control.
Spider mites are one of the most destructive pests, since they can build up into large numbers.
Snails and slugs are attracted to wet soil. Control them by letting the soil dry out.
You can make traps for snails and slugs by burying a jar in the ground so the top is ground level. Put a mixture of water sugar and yeast in the jar to bait them in.
Some beneficial insects are: ladybugs, assassin bugs, damsel bugs, ground beetles, lacewings, and trichogramma wasps.
Insecticides are particularly dangerous to humans because they can be very poisonous to us as well as the insects.
Aphids may be black, white, pink, or pale green. To control aphids use lacewings and ladybugs or hose off plants with a lot of water.
Crop rotation helps prevent pests and diseases.
An advantage of insecticides is that they can really cut down on populations and stop damage to plants.
A disadvantage is that they can kill beneficial insects such as praying mantises and lady bugs.
Use your local extension service. They can help with identification, prevention, and management.
Books
Check out this list of books to help identify and manage pest problems.
By practicing a few basic gardening principles, you not only will improve the quality of your produce, and prevent disease, but also will reduce the need for chemical sprays.
The steps listed in this site should help get you get your garden off to a better start, allowing you to grow healthier disease-free garden plants.
Diagnosis
Look up information about diseases in a book or send them into the extension service to identify them. There are many web sites that provide pictures to help identify diseases. Here is a site where you can look up diseases that affect different plants.
Generally prevention of disease in your garden is much easier, and more effective, than treating a disease after it has affected the plant. This web site gives information about three key topics on disease prevention.
