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
 
desert landscaping

Photo courtesy of Desert Water Agency

There is a positive trend toward  utilization of native plants in Idaho home and business landscapes. The goals of this type of landscaping are myriad, including water conservation, reduced maintenance, attraction of wildlife, uniqueness, and expression of personal creativity. Regardless of the reasons, native landscapes can be beautiful and effective if designed and completed properly. Here are some guidelines that will help you successfully design and establish a native landscape. They closely resemble the steps for establishing a traditional landscape, but differ in a few important aspects such as plant materials and maintenance planning.

  1. Complete a yard survey and map the existing landscape. Note problem areas that are difficult to manage and may be appropriate for native landscapes.
  2. Determine the areas to be planted using native or water conservation materials. It is not necessary or desirable to make an entire landscape native. Some areas should be more traditional with good shade, turf for recreation, leisure areas, and flower beds for consistent color. However, the location of native plantings will determine much of the design. Areas removed from public scrutiny, such as property corners and large back yards, can remain informal and will have less demand for maintenance. Native plantings in public areas, such as around the house entrance, can be as pleasing as traditional landscapes, but will require a more elaborate design.
  3. Design the native planting areas in such a way that they provide continuity and flow with the rest of the landscape. Zone the irrigation system to meet the needs of the native plants. Some areas may need less water if xeriscape principles are followed, while other areas (such as water features and lowland plantings) may actually need more water. Recognize that if a native planting is designed for low water use, it may be necessary to add landscape features other than plants, such as rocks or wood objects to maintain season-long interest, color, and texture.
  4. Choose plant materials that will provide balance, color, line, and movement and complement the rest of the landscape while at the same time meeting the goals of the design. Carefully consider transition zones between traditional and native components of the landscape and avoid sudden shifts in plant type. Carefully consider the mature size of all plant materials and arrange plantings accordingly. Do not mix plants with vastly different water or maintenance needs.
  5. Once the design is complete, install the new landscape using procedures outlined in the section above. In the case of a water-conserving landscape, remember that newly established plants are not especially drought tolerant for the first season and may need some supplemental water for several months.

There are some outstanding publications available on-line that provide detailed instructions for establishing a native landscape. Here are a few of the best that are appropriate for Idaho:

Utah State University provides an excellent instruction manual for planning, designing, and establishing native plant landscape.

r. Stephen Love, University of Idaho, has created a list of native plants that are suitable for landscaping in Idaho. Included in his document is contact information on where to purchase the listed plants. This document  is periodically updated.

The Bureau of Land Management published and internet document entitled, Landscaping with Native Plants of the Intermountain Region. It serves as an excellent native plant selection guide, complete with pictures, and also contains information about sources for native plants.

Several photographs utilized in this discussion of landscaping were supplied courtesy of Gizmo Creations, LLC, Merrifeld, Minnesota.

 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
 
rock garden

Images courtesy of Gizmo Creations

Select plants that meet your design objectives. Important considerations include the following:

  1. Function: ­Select plants that have the appropriate mature size, shape, and structure.
  2. Attractiveness: ­Make sure the plants have the desired color and texture characteristics.
  3. Cold hardiness and/or heat tolerance: Check to make sure the plant is adapted to the temperature zone for your area.
  4. Reduction of maintenance: Select species that require less water and fertilizer inputs. Also avoid plants that require excessive pruning and cleanup.
  5. Safety: This is especially important in areas that children will use. Try to reduce the number of plants that may have poisonous fruits, flowers, or foliage or that have thorns or spines that can cause injuries.
  6. Plantings near utilities: ­Make appropriate selections that will not cause interference.
  7. Economy: Make choices of plant material type and size based on affordability. Planting smaller plants will often allow planting of desired species.
  8. Use of native species: If a natural landscape is desired, native plants may be appropriate because they are better adapted to low maintenance situations within their home region. In Idaho, native plants can be more drought tolerant than nonnative species.
  9. Noxious nature: Noxious weeds are a serious problem in agricultural areas. If you plan to purchase or introduce plants from out of state, contact your local Extension educator for information or the County Weed Control supervisor about noxious weeds in Idaho.

Here are a few other considerations when buying plants:

  1. To ensure greater adaptability to your area, purchase plants that local seed sources have produced, and
  2. To save money and allow inspection prior to purchase, check local nurseries before purchasing plants via mail order.

The University of Idaho, Washington State University, and Oregon State University have jointly published an outstanding publication listing plant species adapted to Northwest landscapes, PNW 500 Plant Materials for Landscaping.

 August 20, 2012
Aug 172012
 
MarmotWhat is a marmot doing in my yard?

In Idaho, we use the name rockchuck for the yellow-bellied marmot (Marmota flaviventris).  In some places they are also called “whistle pigs.”  Marmots are rodents and are the largest member of the squirrel family.   They look like an overgrown ground squirrel with a yellow-tan belly.  Males can weigh as much as 11 pounds.

Marmots live among rocks where they can find and build burrows.  Luckily, they do not indiscriminately dig burrows in open ground like their eastern “woodchuck” cousins. They are common in Idaho’s warm valleys and are often seen in the foothills, even near cities, and also around the edges of lava formations. It is a common site in southern Idaho to see yellow-bellied marmots in springtime sunning themselves on rocks along roadsides.  In the summertime, marmots mostly emerge from their dens and feed at night. For that reason, it is sometimes hard to identify the culprit when damage is discovered in the garden.

Marmots tend to live in social colonies, are prolific breeders,  and can become serious garden pests if present in large numbers.  Marmots will eat any tender, green plants but especially love succulent vegetables.  They are voracious and a few marmots can strip a vegetable garden in a few nights. Marmot damage is unique in that they eat plants to the ground, giving them a “mowed” look. Other pests tend to be selective in what they eat.

Benefits and conflicts

Marmots provide little direct benefit to the homeowner. They can be interesting to observe during the times of the year they are outside their burrows. Conflict with marmots come directly as a result of their tendency to raid the garden and eat anything that looks like a plant, including the lawn.

Strategies for coexistence and control

In agricultural areas, when marmot damage becomes severe, action is taken to eliminate the problem through shooting, gassing, or poisoning. For the homeowner, these options may not be appropriate for a number of reasons. Also, many gardeners are willing to share their produce, as long as the marmots do not take the lion’s share. Following are ideas for dealing with marmots if they become a problem.

Remove them through trapping: Live traps baited with succulent leaves or sprigs of clover can be used to capture marmots, which then can be moved to a more suitable habitat. To keep the pests from returning, relocate them to a place at least five miles away.  

Plant a “marmot garden:” If the marmots are not too numerous, you can keep them from damaging precious plants by planting an attractive feeding spot close to the den.  Given their preference, marmots will eat succulent clover over most other types of plants, so a plot of red or white pasture clover would be a good choice for your “marmot garden.”

Build a fence: Placing a marmot fence around choice vegetation can be a good alternative, but the job must be done right.  Marmots excel at both digging and climbing.  The fence must made of mesh wire, and be at least 4 feet tall and preferably bowed outward at the top with the bottom buried 12 to 18 inches into the ground. Or form an L-shaped fence with the lower edge leading outward and buried about 2 inches making it harder for the marmot to dig underneath. In reality, fences are of questionable value in keeping marmots at bay.  One exception to this is the use of electrified fencing with multiple wires spaced from just above ground level to about 2 feet up.

For more information
 August 17, 2012
Aug 172012
 
native flowers

© 1992 Gary A. Monroe

According to the National Audubon Society and the National Wildlife Federation, native plants provide the best overall food sources for native wildlife and may support 10 to 50 times as many species as non-native plants. Not only are native birds adapted to native food sources, but native plants offer native wildlife both familiar nesting sites and useful cover. Another advantage is native plants generally demand less fertilizer, water, and pest control in the landscape, since they’re adapted to regional soils and climate.

Native plants are increasingly available for sale in Idaho’s progressive nurseries. For information on specific species, see:

 August 17, 2012
Aug 172012
 

Experts agree that only a very small percentage of the insects and spiders in our yards and gardens are actually pests, feeding on our desirable vegetation or infecting it with plant diseases. Indeed, many insects are helpful partners in our gardens, devouring aphids and other plant-eating pests. Pollinators like honeybees and butterflies are essential participants in the reproduction of many flowers, fruits, and vegetables. Some small, stingless wasps or flies assist us by laying their parasitizing young on or inside doomed pests. Although beneficial insects won’t keep our yards pest-free, their contributions should not be underestimated.

Helpful links:

Biological Control: A Guide to Natural Enemies in North America, Cornell University

IPM Online, University of California

caterpillarHelping beneficial insects feel at home

As a gardener, there are things you can do to help sustain natural populations of beneficial insects:

Provide their preferred and alternative foods – Scatter a wide assortment of flowering plants throughout your garden and landscape or cluster them in a designated bed or border. Because different beneficial insects use pollen and nectar at different times, choose diverse plants with long, overlapping bloom periods. Pollinators aren’t the only beneficials that rely on flowering plants. Nectar can help parasitoids (insects that develop in or on another insect pest) span periods when hosts are few. Nectar, pollen, and plant juices can also help predators (insects such as ladybird beetle larvae, above,  that consume other harmful insects) survive times when prey numbers are low.

Provide shelter – Beneficial insects need protection from predators and human disturbances. These beneficial insects can find cover in perennial flower beds, hedgerows, cover crops, and mulches.

Provide water - Bird baths, shallow containers, or temporary puddles, with sticks or rocks for perching, can help beneficial insects through dry periods. Change the water every two or three days to discourage mosquito breeding.

Protect them from insecticides - Broad-spectrum insecticides kill beneficial insects right along with pests. To minimize impacts on beneficial insects, choose chemicals that are less toxic and more specific. Consider these environmentally “softer” alternatives: insecticidal soaps, horticultural oils, botanicals, Bacillus thuringiensis (Bt), and insecticidal products that act specifically as stomach poisons to foliage-feeding pests.

 August 17, 2012
Aug 172012
 
blue fescue

Fescues add texture to naturalized plantings. Photo courtesy of Judy Sedbrook

Water Conserving Landscapes

These grasses require little care and minimal water after establishment to remain attractive. They are generally drought and heat tolerant.

Common Name Scientific Name Regional Adaptation
Arizona Fescue Festuca arizonica N, SW, SC, SE
Big Bluestem Andropogon gerardii N, SW, SC, SE, HA
Blue Fescue Festuca glauca N, SW, SC, SE, HA
Blue Grama Bouteloua gracilis N, SW, SC, SE, HA
Blue Oat Grass Helictotrichon sempervirens N, SW, SC, SE, HA
Idaho Fescue Festuca idahoensis N, SW, SC, SE, HA
Indian Grass Sorghastrum nutans N, SW, SC, SE
Indian Rice Grass Oryzopsis hymenoides N, SW, SC, SE, HA
Little Bluestem Schizachyrium scoparium N, SW, SC, SE, HA
Prairie Dropseed Sporobolus heterolepsis N, SW, SC, SE, HA
Prairie June Grass Koeleria pyramidata N, SW, SC, SE, HA
Sand Love Grass Eragrostis trichodes N, SW, SC, SE
Side Oats Grama Bouteloua curtipendula N, SW, SC, SE, HA

Maiden grass

Maiden grass holds up well in winter. Photo courtesy of Judy Sedbrook

Naturalized Plantings

Many grasses will thrive under no-care situations in Idaho, even in the driest areas. They can be planted with native wildflowers and shrubs to create attractive, natural-looking landscapes. Some of the best grasses for naturalizing are spreading, rather than clumping in growth habit, giving them the ability to fill in bare areas.

Common Name Scientific Name Regional Adaptation
Arizona Fescue Festuca arizonica N, SW, SC, SE
Big Bluegrass Poa secunda var. canbyi N, SW, SC, SE, HA
Blue Fescue Festuca glauca N, SW, SC, SE, HA
Blue Grama Bouteloua gracilis N, SW, SC, SE, HA
Buffalo Grass Buchloe dactyloides N, SW, SC, SE
Crested Wheatgrass Agropyron cristatum N, SW, SC, SE, HA
Idaho Fescue Festuca idahoensis N, SW, SC, SE, HA
Prairie Dropseed Sporobolus heterolepsis N, SW, SC, SE, HA
Prairie June Grass Koeleria pyramidata N, SW, SC, SE, HA
Sandberg Bluegrass Poa secunda var. sandbergii N, SW, SC, SE, HA
Sheep Fescue Festuca ovina N, SW, SC, SE, HA
Snake River Wheatgrass Elymus wawawaiensis N, SW, SC, SE, HA

Winter grass

Tall grasses provide winter texture

Grasses for Winter Interest

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
Blue Oat Grass Helictotrichon sempervirens N, SW, SC, SE, HA
Feather Reed Grass Calamagrostis x acutifolia N, SW, SC, SE, HA
Flame Grass Miscanthus ‘purpurescens’ N, SW, SC, SE, HA
Korean Feather Reed Grass Calamagrostis brachytricha N, SW, SC, SE
Maiden Grass Miscanthus sinensis N, SW, SC, SE
Northern Sea Oats Chasmanthium latifolium N, SW, SC
Switch Grass Panicum virgatum N, SW, SC, SE, HA

Penn Rub grass in container

Tender fountain grass makes a good container specimen. Photo courtesy of Judy Sedbrook

Tender Grasses Grown as Annuals

Some of the most attractive ornamental grasses are not hardy in Idaho. This includes many of the Pennisetum varieties that come in a remarkable array of foliage and flower spike colors. Many of these will still grow here if treated as annuals. Some of the tender grasses make very good container specimens. Here is a short list of tender grasses that can be grown as annuals.

Common Name Scientific Name Regional Adaptation
Feather Top Pennisetum villosum N, SW, SC, SE, HA
Lemon Grass Cymbopogon selloana N, SW, SC, SE, HA
Purple Millet Pennisetum glaucum N, SW, SC, SE, HA
Ruby Grass Melinus nerviglumis N, SW, SC, SE, HA
Tender Fountain Grass Pennisetum setaceum N, SW, SC, SE, HA
 August 17, 2012
Aug 172012
 

The term perennial refers to non-woody plants that live and flower for three or more years. Some are short-lived and will last in the garden for only three to four years. Others will live and bring vibrant color to the garden for many years. Most perennials will die to the ground over winter and regrow from crowns or roots when warm spring weather arrives.

LupinePerennials provide an advantage over annuals in that they do not need to be replanted every year. They also require very little in the way of fertilizer, and in some cases water inputs. A disadvantage is that many perennials do not flower over the entire summer. This can be overcome by planting many complementary species to ensure that at least some are in bloom at any given time. Many perennials are planted for their interesting form or beautiful foliage.

Perennial plants can be used to create interest in any landscape. They mix well with rocks, fences, hardscaping, and other permanent landscape features. They are best used in places where they can establish a deep and healthy root system, such as in traditional beds, rock gardens, or borders. Many perennials can thrive in situations that are problematic for other types of plants, making them good specimens for sloped areas, water conserving gardens, poor soils, and native plantings.

In this section, you will be guided through information on selecting, planting, and caring for perennial flower and foliage plants. Ornamental grasses and bulbs, although technically considered perennials are covered as separate topics due to their unique characteristics and management requirements.

 August 17, 2012
Aug 102012
 

Native plants are receiving ever-increasing attention in the world of home and business landscaping. There are very good reasons for using native plants in our landscapes and gardens. These plants are adapted to local conditions. Consequently, they remain healthy and beautiful with less use of water, fertilizers, and pesticides. They can be used to create landscape themes that are in harmony with their surroundings. They also lessen the chance of importing invasive and destructive exotic species.

A scopulorum

But landscaping with native plants is not without problems. The main issues are identification of suitable native species for specific landscape uses and, maybe even more frustrating, finding source of native plants once a design is developed. The industries that market plants and designs for traditional landscapes have taken decades to meet customer demand and effectively supply myriad beautiful garden plants. It will likely take the native plant industry many years to become equally efficient. But, that is no reason for the native plant enthusiast to despair. There are beautiful plants for the landscape. There are also numerous small nurseries that can supply those plants. Lastly, there are designers that specialize in native plant landscape. You simply have to take the time to find the professionals that can supply what you need.

Sometimes, we think that using native plants in the landscape means adopting an unfamiliar palette of plants, or being limited to creating a front yard that looks like a sagebrush prairie (it should be said that elements of a desert ecosystem can make a very interesting and beautiful landscape). However, nothing could be further from the truth. The reality is that many native plants are already common in many of our most beautiful yards. Some of the plants we are all familiar with include white fir, blue spruce, Engelmann spruce, limber pine, red-twig dogwood, common juniper, Oregon grape, cinquefoil, currant, elderberry, ornamental fescues, many hyssops, columbine, some asters and daisies, blanketflower, coral bells, and many types of penstemons. Most of these plants can withstand a heavily watered yard, making them useful in a traditional landscape. Many other native plants can be used to create very attractive water-conserving landscapes.

University of Idaho researchers have begun a process of domesticating and evaluating native plants for use in Idaho landscapes. Although this research is in its infancy, it has resulted in considerable new information about native plants with horticultural value that are adapted to the dry conditions and high pH soils of southern Idaho. Dr. Stephen Love, leader of the native plant domestication project, has created a document that contains a list of native plants suitable for landscape use. The document also lists nurseries that supply these plants in quantities consistently sufficient for a home landscape project and sometimes sufficient for much larger projects.

The document, entitled Dr. Love’s Favorite Native Plants and Where to Buy Them can be viewed and downloaded by clicking on the link attached to the title. Questions concerning the document can be directed to Dr. Stephen Love.

 August 10, 2012