UI Extension Master Gardeners UI Extension Events UI Extension Idaho Landscapes and Gardens Seasonal Topics UI Extension Idaho Landscapes and Gardens Get Answers UI Extension Idaho Landscapes and Gardens UI Extension Idaho's Growing Regions University of Idaho Extension UI Extension Idaho Landscapes and Gardens UI Extension Idaho Landscapes and Gardens Image Map
Aug 202012

Whether you are developing a new landscape or renovating an old one, it is important to have a plan before doing anything with permanent implications. In the long run, not having a plan may create maintenance problems and reduce the overall appearance of the landscape. The following steps will help you develop a plan for a landscape that is both functional and aesthetically pleasing.

Landscape plan

Landscape Plan 1. Image courtesy of Gizmo Creations

Define Your Objectives and Constraints

This is the most important step of the landscape process. Establishing clear objectives and constraints at the beginning will help you achieve the benefits you hope to receive from your landscape plan. In practice, decide what type of layout best fits the needs of your household, while working within existing economic, social, environmental, and physical constraints.

1. Possible objectives:

a. Low maintenance (reduced watering, pesticide and fertilizer applications, less mowing).
b. Privacy.
c. Adequate recreation area.
d. Enhancement of appearance.
e. Attraction of wildlife habitat (includes forage and cover for birds and desirable insects).

2. Possible constraints

a. Environmental conditions (includes climate, soil, and precipitation).
b. Physical barriers or obstacles on the landscape.
c. Social (includes public ordinances restricting water use or plant selection).
d. Economic.
e. Physical handicaps.

Texas A & M University provides an excellent web site on landscape planning that will give more detail on how to assess and site and complete a plan of work.

 August 20, 2012
Aug 202012

Gather as much information as possible about your site and the area where you live. Make a preliminary map of your property, drawn to scale, that includes the locations of your house, buildings, sidewalks, and driveway. Indicate on the map, or on a separate sheet of paper, the following information:

Landscape Inventory.

Landscape Inventory. Image courtesy of Gizmo Creations

  1. Regional climate: In Idaho, cold hardiness is a critical factor for determining plant survival. Idaho covers five USDA hardiness zones, 3 to 6, (-50 to -10º F), with temperatures being affected by elevation and latitude. See a map of USDA hardiness zones. Heat and wind can also be considerations in the southern valleys of Idaho.
  2. Microclimates: These zones of sunlight, temperature, humidity, and wind that are unique to your landscape and are different (more or less severe) from the regional climate. When conducting a site analysis, look for potential problem areas such as hot spots, frost pockets, wet spots, or windy places, or shaded areas. Also look for protected places where tender plants can thrive. Mark these microclimates on your preliminary map for future reference.
  3. Soils: Proper soil conditions are critical to plant growth and survival. Consider the drainage, soil pH, texture, and organic matter when assessing soil-related characteristics of the landscape. Remember, most urban or residential soils are disturbed soils and probably do not have the good characteristics of native topsoil. It is possible in a small area to improve soil using various soil amendments.
  4. Topography: Lay of the land can affect microclimate and drainage, and make some areas difficult to plant and maintain.
  5. Existing plant materials and structures: Show existing plants, sidewalks, driveways, patios, and other structures on your preliminary plan.
  6. Access: Besides driveways and sidewalks, plot “traffic” areas around the landscape. Consider ways to improve access to your home or other parts of the landscape.
  7. Easements: Draw these on your map to prevent planting any permanent plant materials in these areas.
  8. Overhead utility lines, sewer lines, underground cables, and transformers: Note these on your preliminary site plan and plan accordingly. A simple rule for planning around utilities is to use plant materials that when mature will not touch or interfere with utility equipment. Note: For more information, read UI Extension CIS 991, Landscaping and Utilities: Problems, Prevention, and Plant Selection.
  9. Views: Assess views looking from and toward your house. Determine what you want to see or don’t want to see.
  10. Available water: Show the location of your water sources. If your property has areas that are difficult to water, you may want to modify your plan to meet the needs of these areas by using drought tolerant plants or hardscape (nonliving) materials.
  11. Local ordinances: Consult state and local authorities for specific regulations about planting trees and shrubs along streets, sidewalks, and rights of way.

A site maintained by Mississippi State University provides more information on conducting a site survey.

 August 20, 2012
Aug 202012
Define Use Areas

You can divide use areas into three major categories. Note: There are no distinct boundaries on these areas, and they will frequently overlap in terms of function and appearance.

  1. Public areas: These are usually associated with the front of your landscape. The primary function of these areas is to provide an aesthetically pleasing entrance to your home.
  2. Private areas: These are the areas used for recreation, family activities, and entertaining.
  3. Service areas: The areas are reserved for the vegetable garden, composting, pet and livestock areas, storage sheds, woodpiles, and other utilitarian functions. They can resolve multiple problems by overlapping with areas that are difficult to maintain, have limited access to water, or have poor soil.

For more discussion on identifying use areas, see this University of Missouri site.

landscape plan

Use areas. Image courtesy of Gizmo Creations

Define Planting Areas

Plot planting zones based on water needs or plant maintenance requirements.

  1. Hydrozone, or group plants with similar water needs in the same areas. To conserve water, do not mix plants that have low water requirements with plants that have high water requirements.
  2. Reduce maintenance activities by grouping plants with similar maintenance requirements together. In general, perennials, shrubs, and trees generally require less frequent maintenance than annuals. For a detailed descriptions of low maintenance landscaping principles, see the publication Low Input Landscaping.
  3. Design planting areas to meet the objectives of your landscape plan. Consider the need for privacy, security, wildlife attraction, etc.
 August 20, 2012
Aug 172012
Revennae grass

Revennae grass serves the role of pampas grass in cold climates. Photo courtesy of Judy Sedbrook

As with any perennial, proper site selection is critical for success with ornamental grasses. Soil preparation in a perennial bed is completed only one time, just prior to planting and must be done properly. First, kill and remove any persistent weeds, especially grasses. Such weeds are difficult to manage once the beds are planted. This may take several months and multiple applications of a systemic herbicide. Except in native naturalized plantings, 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 the equivalent of 3 lb/1000 sq. ft. of nitrogen in the form of a complete fertilizer, such as 5-10-5.

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 too 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.

 August 17, 2012
Aug 172012

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
Aug 172012
Drought Tolerant Perennials

Some perennials can withstand hot temperatures and limited water availability and still be attractive. Below is a partial list of such plants.

Common Name Scientific Name Regional Adaptation
Aster (native species) Aster spp. N, SW, SC, SE, HA
Beach Wormwood Artimisia stelleriana N, SW, SC, SE, HA
Blanket Flower Gaillardia . grandiflora N, SW, SC, SE, HA
Butterfly Weed Asclepias tuberose N, SW, SC, SE, HA
Candytuft Iberis sempervirens N, SW, SC, SE
Coreopsis Coreopsis spp. N, SW, SC, SE
Globe Thistle Echinops ritro N, SW, SC, SE, HA
Lupine Lupinus spp. N, SW, SC, SE, HA
Mullein Verbascum spp. N, SW, SC, SE, HA
Orange Coneflower Rudbeckia fulgida var. sullivantii N, SW, SC, SE
Penstemon Penstemon spp. N, SW, SC, SE, HA
Purple Coneflower Echinacea purpurea N, SW, SC, SE, HA
Pussytoes Antennaria dioica N, SW, SC, SE, HA
Red Hot Poker Kniphofia uvaria SW, SC
Red Valerian Centranthus rubber SW, SC
Rock Cress Arabis caucasica N, SW, SC, SE, HA
Russian Sage Perovskia atriplicifolia SW, SC
Sage Salvia officinalis N, SW, SC, SE, HA
Sea Pink (Sand Wort) Armeria maritime N, SW, SC, SE, HA
Silver Mound Artimisia schmidtiana N, SW, SC, SE, HA
Stonecrop Sedum spp. N, SW, SC, SE, HA
Sundrops Oenothera fruticosa SW, SC, SE
Veronica Veronica spp. N, SW, SC, SE
Yarrow Achillea spp. N, SW, SC, SE, HA

Key to regional adaptation notes:
N = Northern Idaho valley locations in USDA zones 5 & 6, Moscow to Sandpoint.
SE = Southeastern Idaho valley locations in USDA zones 3 & 4 from Rexburg to Pocatello.
SC = South-central Idaho Magic Valley locations in USDA zones 4 & 5, Burley and Twin Falls.
SW = Southwestern Idaho Treasure Valley locations in USDA zones 5 & 6, Boise area (also Lewiston). HA = High altitude (>5,000 ft) areas of central, southeastern Idaho and similar locations elsewhere.


Bellflower prefers moist soils

Perennials for Moist Conditions

Although consistently wet or moist soils are not common, especially in southern Idaho, such sites are often created artificially in the landscape. Below is a list of plants that thrive under such conditions.

Common Name Scientific Name Regional Adaptation
Astilbe (P) Astilbe spp. N, SW, SC, SE
Bee Balm Monarda didyma N, SW, SC, SE
Bellflower Campanula glomerata N, SW, SC, SE, HA
Cardinal Flower Lobelia cardinalis N, SW, SC, SE, HA
Delphinium Delphinium elatum N, SW, SC, SE, HA
Globeflower (F) Trollius europaeus N, SW, SC
Hosta (F) Hosta spp. N, SW, SC, SE, HA
Gooseneck Loosestrife Lysimachia clethroides N, SW, SC, SE
Ligularia (Leopard Plant) Ligularia spp. N, SW, SC, SE
Queen-of-the-Prairie Fillipendula rubra N, SW, SC, SE, HA
Rock Soapwort Saponaria ocymoides N, SW, SC, SE, HA


Columbine is among shade tolerant perennials

Shade Tolerant Perennials

Perennials can be the backbone of shade gardens. Many of these plants are native to sites where partial or full shade is prevalent. They can be valuable for situations where other plants are marginally adapted. Below is a list of perennials that thrive in partial or full shade.

Common Name Scientific Name Regional Adaptation
Alumroot (Coral Bells) (P) Heuchera sanguinea N, SW, SC, SE, HA
Astilbe (P) Astilbe spp. N, SW, SC, SE
Autumn Fern (F) Dryopteris erythrosora N, SW, SC, SE, HA
Bergenia (P) Bergenia cordifolia N, SW, SC, SE, HA
Bishop’s Goutweed (F) Aegopodium podograria N, SW, SC, SE, HA
Bleeding Heart (P) Dicentra spp. N, SW, SC, SE, HA
Bugleweed (F) Ajuga reptans N, SW, SC, SE, HA
Cardinal Flower (P) Lobelia cardinalis N, SW, SC, SE, HA
Columbine (P) Aquilegia x hybrida N, SW, SC, SE, HA
Deadnettle (F) Lamium maculatum N, SW, SC, SE, HA
Foxglove (P) Digitalis purpurea N, SW, SC, SE
Globeflower (F) Trollius europaeus N, SW, SC
Heuchera (P) Heuchera sanguinea N, SW, SC, SE, HA
Hosta (F) Hosta spp. N, SW, SC, SE, HA
Japanese Painted Fern (F) Athyrium nipponicum N, SW, SC, SE, HA
Japanese Spurge (F) Pachysandra terminalis N, SW, SC, SE, HA
Liriope (F) Liriope spp. SW
Meadowrue (F) Thalictrum spp. N, SW, SC, SE, HA
Ostrich Fern (F) Pteris modulosa N, SW, SC, SE, HA
Periwinkle (F) Vinca minor N, SW, SC, SE, HA
Red Barrenwort (P) Epimedium x rubrum N, SW, SC
Sandwort (F) Arenaria spp. N, SW, SC
Yarrow, Fernleaf (F) Achillea spp. N, SW, SC, SE, HA

(P) = can withstand partial shade conditions
(F) = can withstand full shade conditions

Key to regional adaptation notes:
N = Northern Idaho valley locations in USDA zones 5 & 6, Moscow to Sandpoint.
SE = Southeastern Idaho valley locations in USDA zones 3 & 4 from Rexburg to Pocatello.
SC = South-central Idaho Magic Valley locations in USDA zones 4 & 5, Burley and Twin Falls.
SW = Southwestern Idaho Treasure Valley locations in USDA zones 5 & 6, Boise area (also Lewiston).
HA = High altitude (>5,000 ft) areas of central, southeastern Idaho and similar locations elsewhere.

 August 17, 2012
Aug 172012
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
Aug 162012

transplanting a seedlingSoil preparation is critical to success with annuals. Proper site and soil preparation will ensure a healthy environment for annual flowers. First, make sure the site has good quality topsoil. This may require addition of topsoil, particularly in new home sites. Amend the soil by adding 3-5 inches of well-aged compost or manure. This is especially important in the arid, calcareous soils of southern Idaho. Add the equivalent of 5 lb/1000 sq. ft. of nitrogen in the form of a complete fertilizer, such as 5-10-5. The fertilizer choice should be high in phosphorus and should preferably include sulfur. 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 too or after planting, it is a good idea to add two or three inches of mulch (wood chips, bark, etc.) to the soil surface.

 August 16, 2012
Aug 162012

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
Aug 142012

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
Aug 132012

Early spring and early fall are the best times of the year to plant because plant shoot growth is minimal and roots have time to become established after planting. Bare root plants should be planted before bud break in March, April or May. Balled and burlapped and container plants can be planted anytime of the year as long as the soil is not frozen. However, early spring or early fall are still considered the best times to install these types of nursery plants.

Where to Plant

Select plants appropriate for the location in which they’ll be planted. Pay attention to the eventual mature height and spread of a tree or shrub, keeping in mind that some community ordinances may restrict planting of trees near power lines, parking strips, street lights, sewers, traffic control signs and signals, sidewalks and property lines.

Other questions to consider are:
  • Will this tree or shrub drop leaves, flowers, or fruit that may be a nuisance to neighbors?
  • Will this plant receive the sufficient amount of sunlight in this location? Will it shade other plants?
  • Will this plant share moisture requirements with the plants surrounding it? Is it compatible?
  • What kind of care, including pruning, will this plant require?

Many of the resources listed here provide information to help homeowners answer these questions.

 August 13, 2012
Aug 102012

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 102012

Currants, gooseberries, and jostaberries are quite easy to grow in Idaho. These fruits in the genus Ribes were once grown commercially in the United States and Canada. All of them, particularly black currants, are grown in Europe and New Zealand today. American fruit growers are also once more considering currants and gooseberries for commercial production.

Currant and gooseberry production, particularly black currants, has largely been restricted in the United States because these crops can serve as alternate hosts of white pine blister rust, which has caused major problems for the timber industry. At one time, efforts were even made to eradicate all domestic and native gooseberries and currants in the country. Although these eradication efforts failed, the development of new selections of blister rust resistant white pine, currants, and gooseberries has reduced the problems associated with the disease, and restrictions on Ribes cultivation are being relaxed. There are currently no restrictions on growing currants or gooseberries in Idaho.

Download our free how-to guides!
Growing Currants, Gooseberries and Jostaberries in the Inland Northwest and Intermountain West

All Currants and Gooseberries

Cold hardiness: 20 to -31 F
Optimal pH: 5.8 to 6.8

Black Currants

Expected yield: 5 pounds per bush
Age to maturity: 3 to 4 years
Productive life: 15 years or more
Spacing: 8 to 10 feet apart 4 to 5 feet apart in rows

Red and White Currants

Expected yield: 5 to 8 pounds per bush
Age to maturity: 3 to 4 years
Productive life: 15 to 20 years or more
Spacing: 8 to 10 feet apart 4 to 5 feet apart in rows


Expected yield: 5 pounds per bush
Age to maturity: 4 to 5 years
Productive life: 15 to 20 years or more
Spacing: 8 to 10 feet apart 4 to 5 feet apart in rows

Red and white currants are genetically the same, differing only in fruit color. These colorful, tart fruits can be eaten fresh, make excellent jellies and syrups, and brighten up dishes when used as garnishes. Black currants were developed from different species and lack the bright, translucent skins of their red and white cousins. Except for the American black currant variety ‘Crandall,’ black currants have a strong flavor that makes them best suited for processing into jellies, syrups, and other foods. Black currant juices and drinks are rich in vitamin C and other beneficial compounds, and are tremendously popular in Europe. Black currants are also rich in anthocyanins, phenolic acids, and antioxidant capacity, making them particularly healthy additions to the home garden.

Currants are noted for their cold hardiness. You can grow them successfully in USDA Plant Hardiness Zones 3b to 7.

Gooseberries range from white to yellow to green to red in color and vary in size, from small marbles to plum-sized fruits. They resemble grapes in appearance and flavor, and make good substitutes in the garden in locations too cold for grape production.

Jostaberries are hybrids between gooseberries and black currants. The very vigorous, thorn-free canes bear dark purple fruits about the size of medium-sized marbles. The fruits lack the strong black currant flavor and can be used fresh or processed.

Selecting a Site

Ribes are adapted to cool, moist conditions and are noted for their cold hardiness. They do not, however, tolerate high temperatures well, especially when combined with intense sunlight. They can be grown in partial shade, but yields are better in full sun. For reliable fruit production, your site should have 120 to 140 or more frost-free days. Mountain and valley locations in northern and central Idaho are excellent for currants. High temperatures combined with intense sunlight and droughty, alkaline soils can make production difficult in parts of southeastern and southwestern Idaho. In these areas, consider growing currants, gooseberries, and jostaberries in partial shade, preferably screened from the afternoon sun.

Ribes grow best on deep, organic-rich, well-drained soils with good water-holding capacity and a pH of 5.8 to 6.8. They tolerate heavier soils and poorer drainage than raspberries, blackberries, or blueberries, although they grow and produce better when the soils are well drained. On heavy soils, alkaline soils, or poorly drained sites, grow these crops in raised beds at least twelve inches high and three to four feet wide.

Pests and Diseases

Several pests and diseases can make Ribes production challenging in Idaho. Powdery mildew damages stems, leaves, and fruits, and can kill highly susceptible plants. In general, European gooseberries are the most susceptible Ribes crop, followed by black currants and red and white currants. Jostaberries are quite resistant to powdery mildew. Starting in early spring just as the new leaves are emerging, applications of sulfur sprays every two weeks can help control powdery mildew. Stylet crop oil can also help control mildew. Dormant applications of lime sulfur and/or Bordeaux fungicides help control the disease, as does raking up and disposing of leaves and prunings. By far the most effective strategy is to select varieties that are resistant to powdery mildew.

Avoid problems with white pine blister rust by planting resistant varieties. If you live within one mile of native or ornamental five-needled pines, plant only varieties known to be resistant to blister rust. For information on controlling currant and gooseberry diseases, click here.

Several pests can seriously damage currants, gooseberries, and jostaberries if left unmanaged. Imported currant worm, currant fruit fly, and various stem borers are the most common and serious pests. For information on identifying and controlling these pests, click here.


Red and white currants are generally considered self-fruitful, but can benefit from cross pollination on some sites and in some years. For reliable production, plant two red or white currant varieties together. White and red varieties can pollinate one another. Black currants are at least partially self-sterile and you should plant two varieties close together to ensure good fruit set. For black currants, the variety ‘Titania’ is the best blister rust-resistant variety available in the United States. Use ‘Consort,’ ‘Coronet,’ or ‘Crusader’ black currants as cross pollinators.

Because they are highly susceptible to powdery mildew, European gooseberries can be very challenging to grow in Idaho. American varieties, although generally producing smaller fruits, are much easier and more reliable to grow here.

Only a few jostaberry varieties are available. ‘Josta’ is the most common. Other varieties include ‘Jostaki’ and ‘Jostagrande (a.k.a ‘Jogrande’). The latter two should be planted together to ensure cross pollination. Josta is partially self-fruitful and can be grown alone.


Most currants, gooseberries, and jostaberries are pruned while they are dormant during the late winter and early spring, but you can prune any time after the leaves have dropped in the fall. Fall pruning improves air circulation around bushes during wet fall, winter, and spring months, and can decrease disease problems. Remove unwanted canes as close to the ground as possible, and always remove drooping canes that lie close to the ground. Canes are normally not shortened or headed back. Be careful while pruning red currants, white currants, and gooseberries not to damage the spurs. Most of the fruit for these crops is borne on short spurs on two and three-year old canes. Black currants bear most of their crop at the base of one-year-old shoots and spurs on two-year-old wood.

With mature red and white currant, gooseberry, and jostaberry bushes, your goal should be to keep three or four strong, new canes per plant each year, and to remove an equal number of the oldest canes. In this system, mature plants have nine to twelve canes after pruning, three to four each of one-, two-, and three-year-old wood. Remove all wood that is four years old or older.

Black currants are more vigorous than other currants and gooseberries, and you normally leave more canes. As a general rule, leave ten to twelve vigorous canes per bush. If the bushes are very vigorous, leave a few more canes. About half of the canes left after pruning should be one-year-old, with the remaining half being vigorous two-year-old canes. Remove all canes that are more than two years old.

Weed Control

Mulch your plants to provide weed control. Four inches of sawdust mulch around currants and gooseberries helps control annual weeds, maintain soil moisture, and keep soils cool. Rake mulches away from plants in early spring to allow the soil to dry and warm. Cold, wet soils retard plant growth. Ensure that quackgrass and any other perennial weeds are eradicated before applying mulch.

 August 10, 2012
Aug 102012

Blueberries are among the most popular fruits for home and market gardening. Both highbush and lowbush blueberries are native to North America and are used fresh or processed into jams, syrups, compotes, fruit leathers, and pastries. Blueberries are firm and hold their quality well both on the bush and in refrigeration. The fruits are easy to freeze and retain their quality when frozen. Blueberry crops can be harvested two to three years after planting, and reach maximum production in six to eight years. Several types of blueberries are available to gardeners. In Idaho, select varieties adapted to USDA Plant Hardiness Zones 4-6. As a general rule, for long-lived plants like blueberries, select varieties one, or preferably two, zones hardier than your location.

Besides producing fruit, blueberries are attractive in landscapes. The compact bushes are easy to prune and produce brilliant orange to red foliage in autumn. The fruit attracts birds and other animals, making blueberries valuable in wildlife-attracting landscapes. Depending on the variety, mature bushes range from eighteen inches to ten feet in height.

Download our free how-to guide!
Growing Blueberries in the Inland Northwest and Intermountain West


Expected yield:

  • Half-highs 1 to 3 pounds per bush
  • Highbush 8 to 20 pounds per bush

Age to maturity: 6 to 8 years after planting
Productive life: more than 50 years
Hardiness: -15 to -30°F, depending on variety
Optimal pH: 4.2 to 5.2
Exposure: full sun
Plant spacing:

  • Lowbush: 1 foot between plants
  • Half-highs: 2 to 3 feet apart in rows 6 to 8 feet apart
  • Highbush: 4 to 5 feet apart in rows 8 to 10 feet apart
Selecting a Site

Blueberries require acid soils, which greatly limits where they can be grown in Idaho. A soil pH between 4.2 and 5.2 is ideal (pH 7.0 is neutral). Blueberries can be grown, with some challenges, on sites where the pH is as high as 6.0. Blueberries suffer from iron chlorosis on soils with pH values above 6.0 that are common in southern Idaho and scattered throughout the state.

Soils having pH values between 5.5 and 6.0 can be acidified by incorporating sulfur into the soil one or two years before planting blueberries. Soil acidification is not cost effective for large sites or when soil pH values are above 7.0. For small scale production on sites with heavy soils, poor drainage, or alkaline soils, blueberries can be grown in raised beds or containers filled with potting mixes or amended soil.

Sites with cool, moist, well drained loamy sand, sandy loam, and loam soils containing around 3% or more organic matter are best for blueberries. Coarser soils dry out too easily and clay soils inhibit root growth and encourage root rot. Production on silt loam soils is possible, but can be challenging due to poor water drainage. Muck soils and boggy areas are unsuitable for blueberries unless you can create raised beds at least 14 inches above the soil surface. On some sites, increasing soil drainage with buried drainage tiles can improve blueberry production.

While blueberries survive in partial shade, you need full sun exposure to develop good fruit flavor and maintain high yields. Blueberries grown in the shade become tall, spindly, and unproductive, creating bushes that are unattractive and do not tolerate snow loads well.


Blueberries are among the most cold hardy fruits, but there are differences in varieties. The most cold hardy blueberries tolerate temperatures of -35°F or below, and many varieties survive temperatures between -20 and -25°F. Rabbiteye and southern highbush blueberries are not reliably cold hardy in Idaho.

 August 10, 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
Aug 062012

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
Aug 062012

Poor soil drainage is a very common cause of problems in a home orchard. Fruit trees on wet soils often fail to thrive, growing slowly, and eventually succumbing to root diseases. Peaches and other stone fruits are especially prone to problems on poorly drained sites.

Gardeners often add compost or other organic matter to heavy soils to improve drainage. In reality, most organic materials have high water-holding capacities and increase drainage problems when added to already heavy soils. Likewise, adding sand to soils on a low-lying site does nothing to improve drainage unless there is a way for water to drain away from the site.

Drainage tiles (buried pipes with holes along the sides) can be used to drain excess water away from a planting site, provided you have a lower-lying area for the water to drain to. For one or a few trees, raised planting beds twelve inches or more high can significantly improve drainage, particularly when heavy native soils are amended with sand or a lighter-textured soil is brought in to create the beds. For a fruit tree, a bed ten feet in diameter should suffice. The beds can be contained within walls or sloped from the centers outward. Apples and pears on dwarfing rootstocks and peach genetic dwarfs have been successfully grown in large (approximately 20 to 50 gallon) containers. Container culture requires great care to ensure adequate irrigation and fertilization, and to prevent girdling roots.

 August 6, 2012