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potting soil

Planting media should be “soilless.”

The best media for container gardening are ‘soilless mixes’ or commercial potting soils. These are combinations of peat moss, sand, vermiculite, and perlite that do not contain actual garden soil. Soilless mixes provide distinct advantages over soil with respect to water holding capacity, drainage and disease management. This is very important for sustained growth capacity in the limited space of a container.

Potting soil is most easily purchased in bags if the quantity needed is small. If larger quantities are needed, bulk quantities can be purchased at some nurseries. Another option is to mix your own. There are as many possible combinations of ingredients as there are gardeners, but a simple, effective recipe consists of:

5 gallons of vermiculite, 5 gallons of peat moss, 5 gallons of washed sand, to which is added 1 cup of 10-10-10 or similar fertilizer. This mixture can be adjusted by adding a few gallons of compost or regular garden soil, replacing some of the peat with a bark product, or replacing all or part of the vermiculite with perlite..

Ohio State University has published a container gardening site that includes a detailed discussion of potting soils.

 August 17, 2012

Proper site selection is critical for success with bulbs. The soil must be well-drained and attention given to proper light conditions (full sun for most bulbs).

Shovels in soil

Bulbs require deeply worked soil

Soil in bulb beds should be heavily amended with organic matter. Well-aged compost works well. Application of organic matter should be followed by deep tillage, at least 12 in. deep. The bed should be leveled and smoothed, but not packed. Just prior to or after planting, it is a good idea to add two or three inches of mulch (wood chips, bark, etc.) to the soil surface. It may also pay dividends to place some type of edging or border around the bed to slow encroachment of grass or other weeds.


Spring flowering bulbs should be planted in the fall. They require a period of cold weather to bloom and because these plants are generally hardy, the best way to provide cold is let them reside in the soil over winter. In Idaho , the best time to spring plant bulbs is late September through mid-October.

Summer flowering bulbs should generally be planted approximately one week after the last frost. To estimate the last frost date in your area, look at the Idaho chart compiled by Ed Hume Seeds. Some bulbs, such as caladiums and begonias will benefit from being started indoors 6-10 weeks before planting outdoors. They should not be taken outside until all danger of frost is past. In much of Idaho , this typically means 2-3 weeks after the last average frost date. Cornell University Suffolk County Extension has compiled a great discussion of planting and managing summer bulbs.

As a general rule, bulbs should be planted two to three times deeper than the top-to-bottom measurement of the bulb itself. Summer flowering bulbs may be exceptions to this rule and planting instructions should be provided on the purchase package. Planting density varies widely according to species and personal preference. Specific instructions for many species are provided in the Dutch Gardens web site. This site also provides pictures, descriptions, and cultivation techniques for many bulbs.

Before planting, an application of fertilizer should be made. Bonemeal or a high phosphate fertilizer should be placed in the planting hole, followed by the addition of a small amount of soil to prevent direct contact of the fertilizer and the bulb, then the bulb planted. This can be followed up with a small amount of a complete fertilizer (equal to 1 to 2 lb nitrogen per 1000 sq. ft.) at the time the plants emerge. Bonemeal should be used with caution around dogs, who are attracted to the scent and may dig up bulbs planted with bone meal.

Additional planting information can be found in sites sponsored by the Rochester Gardening Club and Iowa State University .

Bulbs are planted in the spring (for summer flowering) or fall (for spring flowering). Most bulbs are planted at least 4-8 inches deep, depending on the size. Fertilization at this time is recommended with a product high in phosphorus. Bone meal is an excellent choice,

Another excellent resource is the University of Illinois Bulbs and More web site.

 August 17, 2012
Perennial weeds must be controlled before planting

Perennial weeds must be controlled before planting

Proper site selection is critical for success with perennials. Because the plants will reside in the same place for many years, they must be adapted to conditions where planted. If not, they may never reach their full potential for beauty in the landscape.

Major soil preparation in a perennial bed is completed only one time, just prior to planting. Consequently, to avoid future difficulties it must be done properly to ensure a healthy environment. First, kill and remove any persistent weeds and grass. Such weeds are difficult to manage once the beds are planted. This may take several months and multiple applications of a systemic herbicide. Next, make sure the site has good quality topsoil. This may require addition of topsoil, particularly in new home sites. Amend the soil by adding 2-3 inches of well-aged compost or manure. This is especially important in the arid, calcareous soils of southern Idaho. Add a complete fertilizer such as 5-10-5 at the equivalent of 3 lb/1000 sq. ft. of nitrogen. The fertilizer choice should be high in phosphorus and should preferably include sulfur in southern Idaho.

After amendments are added, the soil should be tilled to a depth of at least 8 inches, leveled, and smoothed (but not packed). Just prior to, or immediately after, planting it is a good idea to add two or three inches of mulch (wood chips, bark, etc.) to the soil surface. It may also pay dividends to place some type of edging or border material around the bed to slow encroachment of grasses or other weeds.

 August 17, 2012

Whether you have a sandy or clay soil will have a huge influence on the watering practices for your lawn. Sandy soils do not hold very much water and, therefore, lawns growing in sandy soils will need to be watered more frequently. The grass will still use the same amount of water per week, but if the soil cannot hold very much water, you will need to irrigate more frequently. Loamy and clay soils can hold more water than sandy ones and, therefore, lawns growing in clay type soils will not need to be irrigated quite as often.

In either case, apply enough water to penetrate the soil to the depth of the grass roots. Use a shovel or soil probe to determine rooting depth. For most clay type soils it may take 1 to 1¼ inches of water to fill the soil to a depth of 12 inches. For sandy soils, only ¼ - ¾ inch of water is all that may be necessary to fill the soil to a depth of 12 inches. Use a screwdriver to check moisture depth. The screwdriver should easily penetrate the soil to the desired depth you want the water.

In sloped areas, lawns with heavy thatch, or lawns growing in clay or compacted soils, water may need to be applied in small amounts separated by one-half hour increments to allow for adequate water infiltration and to prevent run-off.

 August 16, 2012

It is important to understand the main nutrients that lawn grasses require for adequate growth.

Nitrogen is perhaps the most important nutrient as it helps the grass produce green, healthy leaves. Since leaves are the energy-making factories of the plant, it is important that enough nitrogen be provided to maximize their energy making capabilities without causing an over production of leaves.

Phosphorus is important for strong root growth and is very important during establishment. Since phosphorus does not move readily in the soil and new grass seedlings have limited root systems, providing some phosphorus fertilizer during establishment is very important. Mature lawns have very fibrous root systems and are much more adept at mining phosphorus from the soil. Generally, unless very deficient, fertilizers with low percentages of phosphorus are used for lawns.

Potassium is very important for lawns and helps grasses respond to heat and drought stress. Although deficiencies in potassium are difficult to detect, the importance of potassium in stress management should not be overlooked. Unless a soil test reveals that potassium is very abundant, fertilizers with percentages of potassium similar to nitrogen should be used.

Iron is another nutrient that is important, especially in southern Idaho soils. The high pH soils of southern Idaho tie up iron making it unavailable to the plant causing it to become yellow (iron cholorosis). Iro- containing fertilizers can help alleviate iron chlorosis, but make sure of the type of iron you are buying. Iron in the forms of ferrous sulfate or iron sulfate are absorbed by the leaves. If washed into the soil, the iron quickly changes form and becomes unavailable to the plant. Iron in the form of iron chelate (Fe-DTPA, Fe-EDTA, Fe-EDDHA, and Fe-HEDTA), are more effective as soil applied fertilizers. Iron in this form is available to the plant even when in contact with the soil and the effect is much longer lasting than the foliar-absorbed iron fertilizers.

 August 16, 2012
Aug 162012

The most important part of establishing a lawn is proper soil preparation. One of the main reasons for turfgrass failure is a poorly prepared site with inadequate soil characteristics. New construction in subdivisions requires removal of topsoil to allow contouring for adequate storm water drainage. Too often topsoil is not placed back around homes prior to lawn installation. Understanding the requirements of good seedbed preparation will help the long term success of a lawn.

Using good quality seed is also very important. Read the section on turfgrass selection to choose the correct type of grass for your application. Additionally, make sure to purchase seed that has a high germination rate (85% minimum) and contains minimal weed seed and “other crop seed.”

The best time to seed cool-season grasses in Idaho is late summer and fall for several reasons. Soil temperatures are optimum for seed germination, there is less competition from summer annual weeds, and the newly emerged grass seedlings will not be exposed to summer heat. It is possible to seed a lawn successfully in the spring, but extra care will be needed to help the seedlings along during the hot summer temperatures.

The establishment process includes: Site preparation/rough grading, seedbed preparation, seeding/sodding, post seeding/sodding care.

 August 16, 2012

New home site being prepared for seeding. Note the rock and debris piles to be removed.

Remove rocks and debris from area to be seeded.

Large pieces of leftover construction lumber or tree stumps that are covered with soil will eventually decompose leaving depressions in the lawn and can also lead to the fungus that causes fairy ring. Grade the area sloping away from house foundation at a minimum of 2% (¼ inch fall for every 12 inch run) to allow for adequate drainage of water. At this point in the process is a good time to install an underground irrigation system. However, before installing the system, be sure you know where your landscape features such as trees and flowerbeds will be located so the trees will not later interfere with the irrigation system or the flowerbeds will be properly watered. Before planting a lawn is also a good time to control deep-rooted perennial weeds such as quackgrass, Canada thistle and field bindweed.

After properly grading the subsoil, top soil should be added if not already in adequate amounts on the site (minimum of 6 inches). The final topsoil grade should match the contour of the underlying subgrade.

Seedbed Preparation

Add soil amendments such as compost if the soil is low in organic matter. A soil test will tell you whether the soil requires organic matter or other nutrients. Incorporate the fertilizer and soil amendments to a depth of at least 6 inches.

After the tillage operation, smooth the surface with a rake for smaller areas or drag a piece of chain-link fence behind a riding mower or four-wheeler for larger areas. The final seedbed should be moist, slightly firm leaving a one-quarter inch footprint. During this final raking operation, spread a starter fertilizer and rake into the area. A general rule of thumb is to add a starter fertilizer with adequate phosphorus at a rate of 1 lb nitrogen per 1000 ft².


Seed the area in two directions to ensure adequate coverage, then rake lightly to place the seed at about a one-quarter inch depth. A metal leaf rake works well. Lightly roll the entire area to ensure good seed-to-soil contact using a lightweight roller. Apply a straw mulch, especially on sloped areas, to prevent erosion and help retain moisture as well as buffer temperatures while the seedlings are emerging. It is not necessary to rake away the mulch after emergence if it was applied at the proper rate.

Post Planting Care

Irrigate the area lightly and frequently to keep the surface moist during the germination process. This may require two to three light waterings each day especially during periods of hot, dry weather. A mid morning irrigation and one at mid afternoon may be enough to keep the surface moist, but an additional irrigation may be needed in the early evening as well. Once the seedlings have grown to a height of 1 inch, the irrigations can become less frequent and the amount of water applied can be increased.

The first mowing should be when the seedlings reach just past the desired mowing height. Do not apply any herbicide to the new seeding until the grass has been mowed at least four times. If seeding was done in the fall, a herbicide application could be skipped since all annual weeds will die during the winter. If perennial broadleaf weeds are seen in the fall, they should be controlled, but still wait the minimum 4 mowings before applying a herbicide.


The seedbed should be prepared the same way for sod as for seed. It is also very important that the soil be moist (not wet) at the time of installation to encourage root growth. Sod that is placed on dry soil will have a difficult time growing new roots. Lay sod pieces in a brick-like pattern with edges placed tightly against each other. On sloped areas, place the sod horizontally across the slope and use stakes for steep areas to avoid slippage. Working in long straight lines will help reduce labor and waste. Roll the area lightly after installation to remove air pockets and provide good root-to-soil contact.

Newly sodded areas need frequent irrigation because the grass lacks a root system. An initial irrigation of about one-half to 1 inch should be applied, followed by enough water to keep the soil below the sod moist on a daily basis. For about the first two weeks while the roots are growing, keep checking the soil moisture by lifting up a corner of sod to ensure adequate moisture is present. Avoid traffic on the area for at least 4 weeks to ensure adequate root growth. Sometime during the first year following establishment, a newly sodded lawn should be core aerified to help eliminate any soil layers created between the soil on the sod and the seedbed. Soil layers make it difficult for water and nutrients to move properly throughout the soil profile.

More information about starting a lawn can be found here.

 August 16, 2012

The type of soil that a tree or shrub grows in can affect its nutrient needs. Soil texture and soil structure influence the amount of water, air, and nutrients held in the soil for plant use. Clay soils can be nutrient rich, but have a large amount of fine particles that tend to compact and restrict water and air movement. Sandy soils drain well, but contain many coarse particles that have little capacity for storing water, air and nutrients. Organic material can be thoroughly mixed into soils with high clay or sand contents to help improve soil structure. Repeated applications may be needed depending on the amount applied and the stage of decomposition or type of organic matter used. Organic material should be mixed into the soil up to several years before trees are installed to obtain maximum benefit.

 August 14, 2012

No single symptom tells you that trees or shrubs need additional fertilization. Some nutrient deficiency symptoms can be similar to symptoms of cultural problems or diseases. Slow growth rate, small leaves, fewer flowers, smaller fruit, and pale green or yellow (chlorotic) foliage with mottling between the leaf veins may all be signs of nutrient deficiency.

Two methods of determining nutrient deficiencies include:

Soil Testing

Advantages – provides soil pH, levels of K, P, organic matter content and minor nutrients such as iron or zinc.
Disadvantage – does not provide reliable information on N because N is rapidly lost through leaching or removed by plants

Plant Analysis

There are two methods of determining nutrient deficiencies through plant analysis:

Visual symptoms – include length of shoot growth, leaf color, leaf size, and color pattern and timing of leaf drop

Advantages - N and Fe are often the easiest visual symptoms to identify
Disadvantage- symptoms can be deceiving and/or nonspecific

Foliar tissue analysis – provides the concentrations of specific elements in plant foliage (usually leaves)

Advantages - when combined with soil tests it can provide a good picture of nutrient problem(s) – deficiency or toxicity
Disadvantage- nutritional needs for many landscape plants is unknown

 August 14, 2012

Proper soil preparation provides the basis for good seed germination and growth of garden crops. The steps of soil preparation include testing, amending, and tilling.

Testing the Soil

Contact your local County Extension Office to get instructions and sample bags for testing your garden soil. Soil tests are especially critical in a new garden plot but soil should be analyzed at least once every 3 years because conditions do not remain static. The soil test will tell you how much organic matter and fertilizer is needed. To get a relibale soil test, you first need to take a proper sample.

Rows of vegetables growingAmending with Organic Matter

Organic matter improves soil structure, increases water-holding capacity, improves fertility, and reduces problems with soil diseases. There is no replacement for organic matter in improving soil health and providing good growing conditions for vegetables.

Organic matter can be added in the form of plant waste (such as leaves or lawn clippings), composts, green manures, or aged animal manures. It is necessary to consistently  add organic matter (every year or two) because it rapidly breaks down in the soil.

Using compost is a preferred method of adding organic matter to the soil. Apply organic matter to the garden area by spreading a layer of compost 3 to 6 inches deep on the soil surface and tilling to a depth of 10 to 12 inches, if possible with available equipment.

Another method of adding organic matter to soil is to use green manures, which are any living plant material that is mixed with the soil while still green. Green manure crops include such crops as, for example, wheat, oats, clover, mustard and vetch. Grow the green manure in the part of the garden where you will later chop it while it is still green and immediately till into the soil.

Animal manures are best applied in the fall so they have time to completely decompose and salts can partially leach out of the root zone before spring planting. It is best to use animal manures that have been aged for one or two years before applying to a garden, or used composted manure.

To make your own compost, see Composting at Home for a detailed discussion of how to do this.


In this brief format, it impossible to provide fertilizer application recommendations that will apply to every gardening situation. But, whether you prefer traditional or organic methods, some concepts are universal. For one, nothing can replace a soil test for providing the information required to make appropriate fertilizer application decisions. Two, for vegetable gardens, additions of nutrients in some form will be required to consistently grow a good crop. Knowing the amount of fertilizer elements required will make it easier to choose an appropriate product to apply.

Generally, for most Idaho soils, a fertilizer that is relatively high in nitrogen and phosphorus, contains a moderate amount of potassium, and possibly some sulfur will work reasonably well. Follow the fertilizer label directions or contact your local County Extension Office about application rates and methods. Also, UI bulletin, Using Soil Test Results for Garden Fertilization, contains information on interpreting a soil test and how to determine the quantity of fertilizer product to apply.

Fertilizer requirements for vegetable crops vary widely, which complicates fertilizer application decisions. Some crops, such as peas and beets need very little fertilizer. Most long-season crops, such as corn and melons require fairly large amounts (see accompanying table).

Low nutrient-using crops High nutrient-using crops
Bean Broccoli
Beet Cabbage
Carrot Cauliflower
Chard Celery
Lettuce Collard
Parsnip Corn
Peas Cucumber
Potato, early-harvested Eggplant
Radish Kohlrabi
Rutabaga Leek
Spinach Melon
Tomato, short-season areas Onion
Turnip Pepper
Potato, late-harvested
Tomato, long-season areas


Deciding how to fertilize a vegetable garden should take into account the fertilizer amounts needed by “low-nutrient using” crops vs. “high nutrient-using” ones. If you are planting a garden for the first time, it is almost essential to have a soil test so you know the nutrient status of the soil to help determine how much, if any, fertilizer to apply.

If you have been growing a garden for several years in the same location and have been reasonably satisfied with the production, a soil test may not be essential. However, a yearly application of fertilizer is still likely needed. Using a complete fertilizer product, fertilize your garden with 2 to 3 lb N per 1000 ft2 and immediately till it into the soil at the beginning of the season just prior to planting. This amount should be adequate for the low-nutrient using crops. Then after the plants are up and growing, apply an additional 2 to 3 lb N per 1000 ft2 alongside the row—oftentimes referred to as a “sidedress” application—and water into the soil. For this application, you can use a product that is high in N and low in other nutrients. Use UI bulletin, Using Soil Test Results for Garden Fertilization, to determine actual amounts of fertilizer product to apply depending on the nutrient content of the product purchased.

Sandy garden soils, which do not hold nutrients as well as clay, silt, clay loam, silt loam, and other non-sandy soils, require some modification of the above fertilizer application practices. Only part of the total applied fertilizer should be put down before planting. The rest should be applied in small increments during the growing season. This provides the plants with the required nutrients while reducing losses due to leaching. A soil test will help you determine your soil texture.


The final step in soil preparation is tillage. Ideally, soil should be tilled to a depth of at least 10 inches. This can be very difficult with small garden equipment. If larger equipment cannot be used, it may be beneficial to occasionally fracture the soil to a greater depth by pushing a long-tine garden fork deep into the ground and pulling the handle backward to break up the hard lower layers.

It is important to avoid working soil when it is too wet. This is espcecially true for non-sandy texture soil. Working wet soil breaks down the soil structure causing it to become cloddy and hard. The negative impact of tilling wet soil may last for years. To determine if the soil is dry enough to work (till), take a handful and squeeze it tightly into a ball. If the ball breaks into granular pieces when pressed lightly between your fingers, it is dry enough to work. If the ball remains intact and feels sticky when you squeeze it, wait a few days before scheduling tillage operations.

For more information about soils, soil preparation, and fertilizers, study the Idaho Master Gardener Handbook, Chapter 5: Soils and Fertilizers.

 August 10, 2012
Aug 092012

The term “organic farming” was first used in England in the early 1940s, emerging from the biodynamic movement in which a farm was perceived spiritually as a dynamic, living “whole organism.” The concept was brought to the United States in the mid 1940s and widely promoted by J.I. Rodale, founder of Organic Farming and Gardening Magazine (now Organic Gardening) and author of Pay Dirt: Farming and Gardening with Composts and How to Grow Fruits and Vegetables by the Organic Method. Rodale strongly believed in the relationship between living soil and healthy food was achieved by returning animal manures and plant debris to the system by way of composts. The United States Department of Agriculture defines organic as as “an ecological production management system that promotes and enhances biodiversity, biological cycles and soil biological activity. It is based on minimal use of off-farm inputs and on management practices that restore, maintain and enhance ecological harmony.

The growing and selling of produce and products labeled “Certified Organic” is strictly monitored by the United States Department of Agriculture involving a rigorous certification process and complicity with federally mandated regulations for exclusion of non-approved crop management materials, such as synthetic pesticides and fertilizers.

Many home gardeners would like to reduce synthetic chemical use around their children, pets and environment. While they won’t need to certify their backyards, home gardeners may adopt some of the recommended practices to grow flowers, vegetables, fruits and even lawns by using biological and cultural controls, composts, and organic fertilizers along with conventional methods. Some gardeners may choose to completely exclude the use of inorganic fertilizers or growth regulators to reduce dependence on non-renewable resources. Whatever the desire and intent, there are some universally applicable concepts that will help the organic gardener succeed.

closeup of row of seedlings in dirtOrganic vegetable gardening promotes and enhances natural diversity and biological cycles. Rather than relying on synthetic fertilizers and pesticides, organic gardening is based on making the garden self-sufficient and sustainable. You can ease your gardening practices into the organic arena by starting with some of the easier aspects of organic gardening, such as mechanical control of weeds and insect pests.

The first step in this transitioning a garden to organic is improving and maintaining soil fertility and quality. Healthy, fertile soils are basic to successful organic vegetable and fruit production. Management and addition of organic matter, in the form of composts, manures, green manures, and plant residues, is the most important principle to understand for maintaining soil productiveness in an organic system. Organic matter in various forms should be added to the soil annually. There are also many organic fertilizers that can be used to supplement plant nutrition, especially to meet the need for nitrogen and phosphorus. Utah State University has published an excellent organic fertilizer guide, Selecting and Using Organic Fertilizers.

Pest management is the most challenging aspect of organic gardening. Weeds can be controlled with cultivation, pulling, or smothering using mulches. Insects must be closely monitored and controlled using various mechanical methods, predator insects, baits and traps, mild soaps or directed water streams. There are several organically certified insecticides that are useful in the control of insect pests, including Bacillus thuringenisis, insecticidal soaps, rotenone, or natural pyrethrins.

Diseases are best managed through the use of resistant varieties. It is also important to purchase and plant disease-free seed to avoid introducing disease pests into the garden as well as remove and discard diseased plants, rotate annual crops to different places in the garden each year, and keep the garden area free of weeds and dead plant material that may harbor disease organisms. Some leaf-infecting fungi can be controlled using organic fungicides.

A comprehensive list of approved organic materials can be found on the Organic Materials Review Institute web site.

Organic gardening can be simple or complex, depending on the desires of the gardener. There is plenty of good information available on the topic from numerous authoritative sources. Here are some of the best:

View a simple introduction to organic gardening concepts from Mississippi State University

For information on a straightforward, but more detailed approach to organic vegetable gardening, visit this list of University of Florida publications.

For an in-depth discussion of organic soil management principles, read Producing Garden Vegetables with Organic Soil Amendments from the University of Florida.

If you wish to move beyond a cursory understanding of organic gardening practices, select from a series of publications from the University of California, Davis describing detailed organic production principles.

 August 9, 2012
Aug 092012

Composting is a natural biological process that degrades a diverse mixture of ingredients such as leaves, grass, plant material, etc. into a soil-like material called compost. These degraded organic materials (compost) can then be recycled by applying it to the soil. Composting is a good way to eliminate household and yard waste while at the same time improving garden soil. A healthy soil is critical to gardening success. Composting naturally happens, but we can help speed the process by utilizing techniques that enhance the microbe’s (bacteria and fungi) ability to do their job.

Booted foot pushing shovel into dirtComposting can be pursued at many levels, from a gardener who likes to produce “black gold” to the operation of a multi-acre commercial composting facility. Gardeners who compost their own landscaping and food scraps can follow a few simple guidelines and needn’t worry about complex formulas, chemical equations, or studying microorganisms.

The most common way to compost is to collect organic matter in open piles or place the material into bins or barrels. It is important to use only appropriate organic materials in the compost pile, which includes almost any garden or table waste that is plant-derived. Exceptions are plant materials that may harbor disease, may include noxious weed seeds, or material that has been treated with a persistent herbicide. Materials derived from oily foods or animal products should not be included in a compost pile.

A compost pile is created by layering green plant materials, brown and woody plant materials, and garden soil. Once a pile is constructed, composting success depends on providing microbes with the conditions they need to grow and thrive, which are oxygen, moisture and nutrients. These needs are met by turning (mixing) the pile weekly, occasionally adding water to the pile to maintain good moisture, and adding a small amount of fertilizer that is high in nitrogen. Good compost can be created in as little as six weeks with proper temperature and ideal conditions. With less ideal conditions, it may take much longer.

An optional way to compost is to utilize worms. This technique works for composting inside the home for those who live in apartments or otherwise lack space for the more common ways of composting.

For a comprehensive discussion of composting principles, read University of Idaho bulletin, Composting at Home, or the composting section of the University of Idaho Master Gardener’s Handbook.

See the Penn State site for a simplified version of how do home composting.

Learn how to compost using worms from Washington State University.

 August 9, 2012
Aug 092012

The ideal garden soil is deep, friable, well-drained and high in organic matter. Proper soil preparation provides the basis for good seed germination and subsequent growth of plants. Managing soils for optimal plant growth is an ongoing process that consists of proper tillage, adding amendments, and  proper fertilization and irrigation.

pH range in soilSoils in Idaho vary widely due to topography, climate, and origin. In southern Idaho, most soils have a high pH (alkaline) and contain very little organic matter. These soils may need extra applications of phosphorus and micronutrient fertilizers and should never be amended with lime or wood ash.

Northern Idaho soils can have a relatively low pH (acidic) and contain considerable organic matter. Some of these soils may need the pH adjusted upward with lime.

In either location, soils can vary in texture from sand to clay. The pH of soil is important in determining which nutrients will be readily available to plants (see illustration at left). Sandy soils need constant addition of organic matter, frequent and light applications of water, and constant fertilization. Clay soils may need to be amended with organic matter and/or soil amendments to improve water penetration. It is important to know the characteristics of your soil in order to design an appropriate management plan.

garden soil and handRegardless of soil type, careful use of various amendments can improve soil and provide the best possible starting situation for your plants. The best amendments provide organic matter and consist of manures, composts, peat moss, crop residues, grass clippings, green manures, bark, wood chips, straw, or any number of other materials. The type of amendment chosen is dictated by availability and cost.

Before fertilizing or tilling, it is best to get the soil tested for nutrients, pH and organic matter. Several labs, both university and private, will test your soil for a fee. Once you determine fertilizer needs, broadcast fertilizer evenly on the soil surface and till it in. Make sure the soil is not too wet during cultivation to avoid compaction.

It is important to understand that most plants’ nutritional needs are supplied by the soil. Consequently, proper soil preparation will go a long way toward achieving a successful garden.

For more information on soil preparation, see the brief, but excellent Utah State University publication, Preparing Garden Soil.

Washington State University provides a comprehensive guide to soil management.

 August 9, 2012

Gardeners like to improve their soils, and often do so by adding composts, manures, straw, sawdust, or other organic materials. There are both benefits and risks associated with soil amendments. Perhaps the greatest advantages to organic soil amendments are that they can increase water and nutrient holding capacities on light-textured soils and can be sources of plant nutrients.

Amendments also carry risks. Weeds, pests, and diseases can easily be brought into your garden through contaminated organic materials. Woody materials, such as straw, bark, and sawdust, can create severe nitrogen deficiencies in the soil as they decompose. Woody materials are broken down by microorganisms in the soil. These microorganisms take nitrogen from the soil to use for proteins and other compounds in their bodies. Until the woody material is decomposed and the microorganisms die, the nitrogen is unavailable to plants. An excellent strategy to avoid importing weeds, pests, and diseases and to avoid depleting your soil nitrogen is to thoroughly compost organic amendments before adding them to your garden.

Learn more about composting here.

 August 6, 2012