BEST MANAGEMENT PRACTICES
FOR LARGE AND SMALL GARDENS
IN THE PACIFIC NORTHWEST

There are approximately 12,000 small farms in Idaho, Oregon, and Washington, mostly near large cities and towns. The number of small farms is growing rapidly and may double by the end of the decade. Small farms range in size from 1 to 20 acres. Many small farm owners have horses or other livestock which are fed by intensive management of the farm, often using quantities of fertilizers and chemicals far exceeding quantities used on large scale farms (on a per acre basis).

Small farms can have a significant impact on water quality. Most small farms are concentrated near the larger cities and towns in Idaho, Oregon, and Washington. These farms, or ranchettes, often contain several horses and other livestock. The owner tries to produce all feed for these animals on this small acreage. Thus forage crops are important. Because most small farm owners are relatively affluent and derive most of their income from off-farm sources the cost of chemicals used in the production of forage crops is often not a limiting factor in management. This results in a very high chemical use rate per land unit area.

Large numbers of small farms are appearing in King, Spokane, Pierce, Thurston, and Snohomish counties in Washington; near Portland, Medford, Bend, and in the Willamette and Rouge River valleys in Oregon; near Boise, Coeur d'Alene, and in Canyon county, Idaho. Because of their proximity to urban areas these farms are often situated on or near some of the most sensitive aquifers and surface waters in the Pacific Northwest.

Most small farm owners are environmentally sensitive; however, this group has totally been neglected as far as educational programming for pollution prevention. Numerous programs are in place to educate the urban dweller on home and garden chemicals. Massive federal programs are targeted at the larger farmer. However, since small farms are not eligible for cost share programs, these people often fail to get technical assistance supplied by agencies such as the Soil Conservation Service.

The purpose of this slide set is to provide a background that will enable a small landowner with either a small or large garden to utilize best management practices that will protect the environment.

1. Slide Title This slide set is entitled "Best management practices for large and small gardens in the Pacific Northwest." Funding for the development of this slide set was provided by a grant from the Pollution Prevention Program of EPA Region 10. Owners of small farms and urban dwellers that have gardens and utilize the best management practices introduced in this slide set will help protect both surface water and groundwater quality in the Pacific Northwest.
2. Garden Ecosystem Whether large or small, flowers or vegetables, think of your garden as an ecosystem. An ecosystem is defined as a grouping of plants, animals, and other organisms interacting with each other and their environment in such a way as to perpetuate the grouping more-or-less indefinitely.
3. Garden Ecosystem Look closely at your garden ecosystem. You will obviously see plants, but there is much more! Your plants may include flowering plants, vegetable plants, and even weeds. Your garden is regularly visited by insects, birds, and other animals. Your soil is teeming with life. Your garden ecosystem is indeed very complex!
4. Garden Ecosystem Despite the fact that different gardens support different ecosystems there will be many similar aspects. All ecosystems have the same three basic categories of organisms that interact together in the same ways. The basic categories of biological organisms are: (1) producers, (2) consumers, and (3) decomposers. Producers are generally green plants. Consumers include insects and animals. Decomposers include insects and microorganisms.
5. Producers Producers are the green plants in your garden ecosystem. Plants convert sunlight into energy for plant growth through a process called photosynthesis. In this process, the light energy is used to convert carbon dioxide and water to a sugar called glucose. Oxygen is released to the atmosphere as a waste product. Basically, producers capture all the energy needed to make your garden ecosystem function smoothly.
6. Consumers Organisms which are not producers feed on complex organic materials to obtain energy and nutrients. Organisms which feed on live plant or animal material are called consumers. There are several levels of consumers in your garden ecosystem. Primary consumers are animals or insects which eat the green plants in your garden. Secondary consumers are animals that eat other animals in your garden. Primary consumers use green plants as both an energy and nutrition source. Primary consumers are called herbivores because they eat only plant material. Secondary and consumers of higher orders are called carnivores because they eat meat. Some of your garden consumers are called omnivores -- because they eat both plants and animals.

7. Decomposers Dead plant and animal material and humus are eaten by decomposers that live in your garden ecosystem. There are many organisms that serve as decomposers. Some we can see with the naked eye -- like earthworms and some insects. Other organisms are microscopic in size. The decomposers use dead plant and animal materials for energy. The decomposers are responsible for nutrient recycling in your garden ecosystem. When materials are completely decomposed the liberated plant nutrients like nitrogen, phosphorus, and sulfur can be captured by roots and taken up again by living plants.
8. Ecosystem Balance If left alone, your garden ecosystem will reach a balance between producers, consumers, and decomposers. With minimal disturbance your garden ecosystem will be sound. With balance all materials are recycled.
9. Ecosystem Imbalance Increasing inputs or exports may imbalance your garden ecosystem. Common inputs by gardeners can throw your ecosystem out of balance. These inputs may favor system producers over consumers, producers over decomposers, or consumers over producers depending on the type and quantity of inputs. In addition, exports such as flowers or vegetables from your garden deplete your ecosystem of nutrients. The more inputs and exports the greater the overall imbalance of the system.
10. Ecosystem Imbalance What inputs can throw your garden ecosystem out of balance? These inputs include the use of (1) pesticides, (2) fertilizers, (3) water, and (4) composts. For example, the use of a pesticide may kill more than your targeted organism. It may kill some beneficial insects or plants that naturally reduce the pressure from other pests. Excess water use may result in nutrient leaching below the effective rooting depth of plants, resulting in breaks in nutrient cycling within your garden ecosystem.
11. Imbalance A large imbalance in your garden ecosystem may cause environmental damage or degradation and adversely affect water quality in your community. Imbalances that lead to soil erosion from your garden may damage the surface water quality of nearby rivers, lakes, and streams. Imbalances that result in nutrient and/or pesticide leaching in your garden ecosystem may adversely impact groundwater quality.
12. Garden Concept To protect the garden and surrounding environment we use best management practices. The term best management practices is often shortened to BMPs.

13. BMP Concept Best management practices can be defined as implemented strategies which eliminate or minimize environmental pollution. Extensive research has been conducted to design BMPs for large and small gardens. In many cases these strategies were developed for large farms and then downsized to use on small parcels of land.
14. BMP Concept Best management practices have been designed to be compatible with garden ecosystems. Best management practices that you will see in this slide set can protect the environment without compromising the productivity of large or small gardens.
15. Garden BMPs This slide set contains BMPs for pest management, nutrient management, soil management, and water management. When you use the following BMPs you tend to keep your garden ecosystem in balance. These BMPs will also protect water quality in surrounding ecosystems.
16. Garden Pests Common garden pests include insects, organisms that cause plant diseases, and weeds. There are many different types of each pest. You should try and become familiar with the most common pests that attack the plants you grow.
17. Pesticide Concerns Why should you be concerned about pesticide use in your garden? Well, home gardeners often use more pesticide on a square foot basis than farmers do in large scale production agriculture. Unlike farmers, most homeowners have not been exposed to education programs that teach the mechanics necessary to safely use and apply pesticides. Economics reduce the overall amounts of pesticides used on a large farm; however, economics are much less important on land parcels that are less than 20 acres in size.
18. Pesticide Concerns There are many reasons why pesticides should not be over-used in your garden ecosystem. One adverse affect of pesticide over-use include making your food less safe to eat, especially if residues are left on the harvested plant material. In addition, over-application of pesticides makes handling plants more dangerous.

19. Pesticide Concerns Pesticide over-use will often harm or kill beneficial insects in your garden ecosystem. In addition, earthworms in your soil, birds, and pets can also be harmed or killed. Certain pesticides can also harm the applicator -- you -- if over-used or misapplied.
20. Pesticide Concerns Pesticide over-use can harm your garden ecosystem and surrounding ecosystems. For instance, over-applications of pesticides may result in chemicals running off the surface of your garden during rainfall or irrigation events. The pesticides in the runoff water could reach local streams, rivers, or lakes. On the other hand, some pesticides could leach through your soil and contaminate groundwater. This groundwater is likely your source of drinking water. Over-application of pesticides may result in the accumulation of residues in the soil. These residues may be directly toxic to plant growth or be taken up by plants which in turn result in fruits or vegetables which could be toxic to humans.
21. Pesticide Concerns Over-application of pesticides will often result in pest resistance to the applied chemical. Naturally occurring mutations will create super insects or weeds which will be almost impossible for you to control with pesticides in the future.
22. Pest Management BMPs There are six different BMPs that should be utilized in your garden for effective and environmentally sound pest management. The first and most important pest management BMP is to create a garden with diversity. This can be done in gardens devoted to flowers or food production. Plant a combination of different flowers or vegetables in your garden. Designing a diverse garden will help create a balanced garden ecosystem. This diversity will prohibit the large build-up of any one pest and reduce overall pest damage in your garden.
23. Garden Diversity Garden diversity will provide a good home for beneficial insects and organisms. Plant both annuals as well as perennials to ensure a stable, year-round home for beneficial insects. To avoid pest buildup, rotate annual plants and vegetables to outsmart potential pests and to avoid soilborne diseases. Your diversity strategy will really work! It will take only a short time before you notice reduced pest pressure in your garden ecosystem!
24. Identification BMP It is important to know what is in your garden. This is an important BMP for every garden, large or small. You should be familiar with the vegetables or flowers you are growing. Know their growth characteristics. Learn about common pests and diseases that afflict them. Identify your insect pests! Identify your weed pests!

25. Identify! How do you identify pest problems? First, observation is very important. Find the pest; note what plants it is found on; draw a picture or collect a sample. You have three alternatives for identifying the pest. First, you can buy a book, often called a key, with which you can match your pest to a photograph. Your second alternative is to take your collected sample to your local nursery or home and garden center for identification. Your third alternative is to contact your local Extension office. The Extension agent in your county can help with identification and provide advice to address your pest.
26. Beneficial Insects To keep your garden ecosystem balanced you must protect beneficial insects. This BMP is difficult to implement if you use pesticides in your garden. Beneficial insects will keep many common garden pests in check. You should learn to recognize the eggs and larvae of beneficial insects and avoid harming them!
27. Environmental Solutions When a pest problem is identified, use the most environmentally sound solution! This BMP involves using a strategy which may be more labor intensive than using only chemical or pesticide controls. For instance, it is more environmentally friendly to hand pull weeds in your garden instead of cultivation with a tiller or using a herbicide. With a low level of infestation, it is more environmentally friendly to hand pick insects off plants than using an insecticide.
28. Consider the Environment Some environmentally sound pest management strategies to implement in your garden ecosystem include: using biological controls, trapping insects, and living with a low level of plant damage. You can purchase predatory insects and insect traps from many nursery and garden mail order firms. If pests are only damaging a few leaves on your plants your losses are not great enough to consider using a pesticide.
29. Mulches Instead of spraying weeds with herbicides, consider using mulches to prevent weed growth between your garden plants. Mulches do more than inhibit or retard weed growth. Mulches protect the soil from erosion and moderate soil temperature. As an alternative to pesticides, mulches control weeds and enhance your garden ecosystem.
30. Interplantings You can slow the spread of diseases and pests in your garden by using interplantings. In this example, you see a row of lettuce, a row of tomatoes, and a row of corn. Pests that attack corn are unlikely to attack the tomatoes and lettuce -- thus reducing the ability of the pest to spread and greatly increase in numbers.

31. Physical Barriers Consider using non-toxic solutions to pests. You can use physical barriers to protect your plants. You can purchase physical barriers like floating row covers and net covered cages commercially from nursery and garden supply companies. You can also make your own barriers -- using juice cans or cardboard tubes in your garden. These physical barriers prevent pests from making physical contact with your valuable produce.
32. Non-Toxic Solutions Additional non-toxic solutions to pests may include knocking insects off plants with water or spraying the plants with a soap solution. The soap solution will dessicate the insects. The alternative suggestions to pesticides do not always work; however.
33. Correct Pesticide Use If alternative solutions do not remedy your pest problems, pesticides may become a viable alternative. When used correctly, pesticides kill your pest and do minimal harm to other life in your garden. So using pesticides correctly is a garden BMP after the first four BMPs covered in this slide set have been evaluated for your garden conditions. When using a pesticide you must read and follow the directions on the label of your pesticide container strictly.
34. Pesticide Use To use pesticides correctly you must match the pesticide with your pest problem. Proper pest identification and following the label on your pesticide container are key points here. Use the correct pesticide application rate. Rates too high may harm beneficial pests, cultivated plants, and the environment. Buy only the amount of pesticide you need. Excess chemical should not be stored for a long period of time.
35. Storage and Disposal Store and dispose of pesticides properly. Remember: you should buy chemicals in small quantities only -- so you won't have to worry about storage and disposal problems. If you have to store a leftover chemical it should be placed in a secured area -- such as a cabinet that can be locked. Never store pesticides in your well pump house! When a chemical is no longer of use to you, dispose of it in the proper manner. Check federal, state, and local laws for proper disposal methods for your particular pesticide.
36. Fertilizer Concerns The major problem with nutrient over-use is the potential negative impact on the environment. Commercial fertilizers and organic materials have the potential to contaminate groundwater when over-applied. The nitrogen applied to the garden is converted to nitrate. Nitrate is mobile in soils and can leach into the groundwater. High levels of nitrates in water collected from wells can be hazardous to your health.

37. Fertilizer Over-Use The major problem with nutrient over-use is the potential negative impact on the environment. Commercial fertilizers and organic materials have the potential to contaminate groundwater when over-applied. The nitrogen applied to the garden is converted to nitrate. Nitrate is mobile in soils and can leach into the groundwater. High levels of nitrates in water collected from wells can be hazardous to your health.
38. Fertilizer Over-Use Excessive nutrient applications to your garden will reduce your harvest. Plants require a certain amount of nitrogen (N) to yield well. The plant's growth strategy is to get enough N to produce adequate vegetation, then to produce its flower, fruit, or seed. Too much N will result in excess vegetative growth at the expense of fruit, flower, or seed production. The illustrated example here shows too much N -- resulting in a lot of vegetative growth with poor fruit production for the plant on the right. The plant on the left had enough nitrogen for adequate vegetative growth -- which translated to excellent fruit set and yield.
39. Nutrient BMPs There are five different BMPs that should be utilized in your garden for effective and environmentally sound nutrient management. The first nutrient BMP encourages you to build a healthy soil. Organic matter additions to your soil will do this. Organic additions improve both the chemical and physical properties of your garden soil. Organic additions enhance soil chemical properties by adding essential nutrients required for plant growth. Improved soil structure, water holding capacity, and tilth are physical properties enhanced by organic matter additions.
40. Soil Preparation In addition to adding organic matter you can enhance your garden soil by correct preparation. Your plants will thrive in a slightly acid soil. Maintain soil pH between 5.8 and 6.8. Regular additions of plant materials will result in a healthy biologically active soil. Cover crops improve soil structure, tilth, organic matter levels, and soil nutrient levels.
41. Soil Testing Soil testing is an important nutrient management BMP. Test your garden soil prior to fertilizer additions. It is not difficult to take a soil sample from your garden. If you need information on how to take a soil sample contact your local county Extension office. Soil tests will measure the amounts of plant available nutrients in your garden soil. Some nutrients measured by your soil test include the amounts of plant available nitrogen, phosphorus, potassium, and sulfur.
42. pH and Organic Matter In addition to measuring levels of available nutrients, a soil test measures pH and the percentage of organic matter in the soil. Garden soil samples should be taken to a depth of 12 inches. These tests are valuable since they allow you to apply nutrients at proper ratios. This concept is called balanced nutrition.

43. Nutrient Application Rates Apply correct rates of fertilizers based on soil tests. Adherence to this BMP will protect the environment. Once you determine the correct rate of nutrient to apply to your garden soil you need to select your nutrient source, or fertilizer. You can add nutrients using either organic or commercial inorganic fertilizers. Let's explore your fertilizer options.
44. Inorganic Fertilizers Commercial inorganic fertilizers are sold as solids or liquids and are packaged in boxes, bags, or bottles. Commercial inorganic fertilizers are manufactured from raw products produced in industrial processes. You can purchase inorganic fertilizers from nurseries or from home and garden centers.
45. Fertilizers Every package of fertilizer you purchase has a label with three numbers on it. The numbers are called the fertilizer grade which tells the consumer the amounts of nitrogen (N), phosphorus (P), and potassium (K) in the package. The first number represents the percent N; the second number represents the percent P2O5; and the third number the percent K2O. In this example the fertilizer contains 5% N, 10% P2O5, and 2% K2O. This is also referred to as the fertilizer analysis.
46. Advantages of Inorganic Fertilizers Commercial inorganic fertilizers are convenient to use. Inorganic fertilizers produce plants identical in appearance, taste, and food value to plants produced with organic fertilizers. Inorganic fertilizers are easy to apply, have a high fertilizer analysis, and are uniform in size. Your garden will require a relatively small amount of inorganic fertilizers. Because of high analysis and uniformity of size you can easily measure exact amounts of fertilizer to apply.
47. Inorganic Fertilizers Inorganic fertilizers add only nutrients to your soils. These materials have no effect on soil physical properties such as soil structure and water holding capacity. You can apply inorganic fertilizers in a variety of ways -- broadcasting, banding, or side-dressing.
48. Organic Fertilizers Like inorganic fertilizers, organic materials supply nutrients necessary for plant growth. Manures and composts are examples of organic fertilizers. In addition to providing nutrients necessary for plant growth, organic materials have a positive effect on soil physical properties. Organic fertilizers can improve soil structure, tilth, aeration, and the water-holding capacity of your garden soil. Organic fertilizers have no impact on soil texture.

49. Nutrients in Organic Fertilizers Organic fertilizers have the same chemical composition as nutrients from inorganic commercial fertilizers. However, the nutrients in organic material must be mineralized by soil microbes first and as a consequence are not immediately available to plants. Unlike inorganic fertilizers which have a fertilizer grade on the package label, organic materials vary widely in their nutrient content.
50. Fertilizer Placement Use correct fertilizer placement. This slide shows two options for fertilizer placement -- banding and broadcast. Banding can be defined as placing fertilizer in a small area, a band. The fertilizer should be placed below or to the side of the seed at planting. In contrast, broadcast refers to a uniform placement of fertilizer. Broadcast can occur either before or after planting. If before planting, it is uniformly applied to the soil surface and then mixed in to the soil with an implement. If applied after planting -- it is uniformly applied to the soil surface -- water is required to move the fertilizer into the root zone. By looking at both diagrams it is obvious that the plant that has received a banded fertilizer application has better access to the fertilizer.
51. Application Timing The final nutrient management BMP is correct timing of fertilizer applications. You should try and apply fertilizers as plants need the nutrients. By applying fertilizers when plants need them there is less chance for losses and consequent environmental pollution to occur. This is environmentally responsible management.
52. Soil Erosion Concerns Why should you be concerned about soil erosion in your garden? Soil losses from erosion hurt garden productivity and damage the environment. The illustration on this slide compares garden areas with and without significant soil erosion. Where no erosion has occurred we have large, healthier plants. Conversely, where topsoil has been lost we see smaller, less healthy plants.
53. Erosion Concerns There are many reasons why soil erosion should be prevented in your garden ecosystem. Some adverse effects of soil erosion include a reduction in the amount of plant nutrients remaining in the soil. This is due to the fact that the surface soil is much more fertile than the subsoil. If lost by erosion, the fertility must be replenished by applying larger quantities of fertilizers. In addition to a loss of fertility, erosion losses translate into less soil organic matter, deteriorated soil structure, poorer tilth, and decreased permeability. If your subsoil is rocky, erosion will result in your remaining soil profile having rocks throughout.
54. Sediment Losses Erosion losses from your garden have a detrimental impact on the surrounding environment. Sediment carried in runoff water from your garden can pollute and help choke local surface waters. In addition, nutrients such as phosphorus and nitrogen carried in the runoff water may cause eutrophication, which is rapid aging of local rivers, streams, and lakes.

55. Erosion BMPs There are three different BMPs that should be utilized in your garden for effective and environmentally sound erosion control. The first BMP is obvious -- protect your soil! Bare soil surfaces are vulnerable to erosion. Keep your soil surface covered at all times! Options you can consider include the use of mulches, black plastic, and cover crops. You should sow a cover crop in the fall to protect the soil over the winter and early spring months. The cover crop can be rototilled back into your garden soil prior to seeding your garden in the spring.
56. Soil Structure The second BMP which can be utilized to reduce soil erosion is to improve your soil structure. A soil with good structure resists erosional processes. You can improve soil structure with regular additions of organic materials. Acceptable organic materials include composts, dead plant materials, and many types of organic waste products.
57. Tillage The third soil erosion BMP is about tillage. Perform tillage operations when appropriate. Soils should never be tilled when they are too wet. This practice will damage soil structure, which in turn will make your garden soil more vulnerable to erosion.
58. Water Concerns Why should you be concerned about water use in your garden? Americans use a lot of water. In fact a typical American today uses four times as much water as a great-grandparent did at the turn of the century. In urban areas of the Pacific Northwest water use often doubles when the gardening season arrives.
59. Water Over-Use There are many reasons why water should not be over-used in your garden ecosystem. First of all, water over-use is bad for our future. In many urban and rural areas in the Pacific Northwest we are depleting our groundwater resources. Water tables are falling because we are using our water resources faster than natural forces can replenish them.
60. Chemical Leaching Excess water use in your garden can have an adverse effect on the environment. Excess water causes leaching -- which is the downward movement of chemicals applied to the soils. Chemicals that can leach with excess applications of water include pesticides, nitrates from inorganic fertilizers, and nitrates from composts. If enough water is applied the chemicals can be leached into our groundwater supplies.

61. Surface Water Excessive applications of water can also result in surface water runoff. This runoff may cause erosion if the soil surface is not protected and eventually pollute streams, rivers, and lakes.
62. Water BMPs There are three different BMPs that should be utilized in your garden for effective and environmentally sound erosion control. The first BMP is simple: use water wisely in your garden. Water conservation is important to both us and future generations. Water conservation should be practiced both inside and outside your home. On the outside, repair all leaks in hoses, faucets, sprinkler pipes, and sprinkler fittings.
63. Wise Water Use Water your garden at optimal times! Avoid the warm parts of the day when evaporation losses are greatest. Consider irrigation early in the morning or late at night. Never over-water! Over-watering will cause leaching. Prevent leaching and protect the environment!
64. Save Money You can save money with improved water management. The less water applied -- the lower your water and/or pumping bills will be! Using less water will result in less leaching -- and consequently lower fertilizer bills. Do not apply water below the plant roots! It's a waste of the resource!
65. Water Conservation There are many advantages of wise water use. Some advantages include: saving water needed for drier days or drier parts of the growing season. Wise water use will decrease the peak demand for water. Conservation will help meet the needs of an increasing population.
66. Water Use Water conservation will help reduce the potential negative environmental impact from fertilizer and pesticide runoff. Water conservation will decrease the time required for garden maintenance. Less water will discourage weed growth in your garden. Wise water use will increase plant success rate in times of drought.

67. Water Erosion You should protect your soil from water erosion. This BMP involves both good soil and water management. Use mulches to cover and protect your soil surface from erosion by water. By reducing the size of water droplets from sprinkler systems you reduce the intensity of water impact on your soil surface -- and thus protect the soil.
68. Water Holding Capacity Improve the water holding capacity of your soil by incorporating composts, plant materials, and mulches. This will increase water infiltration and reduce puddling and erosion on the soil surface.
69. Irrigation Efficiency Design your irrigation system for maximum efficiency. This BMP will conserve water, prevent leaching of chemicals, and result in healthier plants. Drip irrigation is the most efficient irrigation system. However, sprinklers are better than using an ordinary water hose. Strive for uniform water applications with your irrigation system.
70. Summary Remember, to protect the environment, your garden ecosystem management program must consider BMPs for pest management, nutrient management, soil management, and water management.
71. Summary Utilization of the BMPs presented in this slide set will make you a steward of the environment. Grow plants that love the Pacific Northwest and remember: Your garden ecosystem can be environmentally friendly!

This slide script, WQ-22, was prepared by R. L. Mahler and K. A. Loeffelman of the Soil Science Division, University of Idaho, Moscow, Idaho 83844-2339.
This slide set and script was funded by a grant from the Pollution Prevention Program of the Environmental Protection Agency, Region 10.

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Revised: January 3, 2003

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