While a house in a hilly area comes with a promise of stunning panoramic  views of the surroundings, to their utter chagrin, homeowners quickly  realize that working on a sloping backyard can be a harrowing task.  However, the old adage, "More work equals to better results" certainly  holds true in case of landscaping a sloping yard which presents  innumerable opportunities for aesthetically pleasing inclusions that  would otherwise look mundane.
When planning a landscape for a hilly yard, it is quintessential  to include this topographical feature as a crucial consideration when  deciding on every aspect of the landscape, from the type of  plants that you intend to use to the design of the garden. Preplanning  will help you to tackle the more cumbersome aspects of  landscaping a slope while yielding astounding results. So, here are some tips on how you can landscape your sloping backyard to create a stunning medley of colors and textures.
Get to know the terrain 
Grading the terrain: Before you draw up plans for landscaping your sloping backyard, it is imperative to study the terrain and the slope to ensure that your landscape will be able to efficaciously handle the drawback of gardening on a slope, while making the most of the natural features of the terrain. 
A simple thumb rule to understand how the extent of  slope will impact your gardening efforts is that the steepness of the slope will be directly proportional to the water you will need for your plants. Because steeper slopes tend to funnel moisture away from the plants, forcing the water and soil to flow downhill, it is vital to get the slope  graded. As a matter of fact, most experts suggest that getting a  sloping yard professionally graded can help you to save a significant  amount of money on watering the steep terrain in the future.
Visual analysis: Alternatively, you could also do a visual analysis of the area. Gauge the severity of the slope  and create a quick diagram labeling the steepest portions of the yard;  make a note of the amount of sunlight that the different portions of the  yard receive. You may also want to include comments on any drainage  problems that may be encountered in specific areas. 
List the various elements of the  landscape: With the diagram in hand, you will be in a better position to place the various landscaping  elements in the drawing such as tress, flower beds, fountains,  walkways, boulders etc. It is crucial to accurately anticipate the area  that the plants and shrubs will cover at maturity so that the landscape does not look too crammed.
Mark the areas for planting: Ideally the trees should be planted at the bottom half of the slope so that they can add stability to the landscape  and prevent soil erosion. The steepest sections should have shrubs with  deep reaching fibrous roots that will hold on to the soil while the  wider plants that will cover large areas at maturity should be planted  at the bottom of the slope so that they can create a neat hedge while affording you all the privacy that you need to enjoy your garden. 
Preventing soil erosion 
Stability and accessibility: Soil erosion is a huge concern when gardening on a slope;  however, depending on the steepness of the area, you will also need to  give a thought to accessibility requirements such as a ladder or other  forms of assistance for climbing. The type of soil and the steepness  gradient will also impact the stability of the yard. 
Drainage and soil erosion: The direction in which the water drains from a slope  will have a bearing on the extent of soil erosion; for instance, if the  water runs down straight to the lower ground, there will be massive  erosion. Using non porous material for landscaping on a steep terrain will further augment the soil erosion problem.
Solving the soil erosion problem: There are several anti erosion measures that can yield remarkable results such as:  
Terracing 
Laying garden paths across the slope
Using boulders and logs to reduce drainage
Building retaining walls with small rocks
Planting specific types of grass
Interlocking walls etc
Using the right types of plants can not only add to the aesthetic appeal  of your garden but also help to reduce soil erosion. As a matter of  fact, mixing different types of greenery is the ideal way to reduce the  water from draining away too quickly. Plants such as deep rooted shrubs  combined with trees like manzanita and juniper will hold the soil tight  for the shallow rooted perennial shrubs and flowering plants like  clematis and day lilies. 
Preparing the ground 
With a list of plants that you intend to use to reduce soil erosion, you are all set to prepare the ground for your  landscape
The compass points need due diligence: Knowing the direction in which  your yard faces will prove immensely useful when choosing plants for the  landscape. Slopes that face to the south or west tend to  drain faster and will have to be watered more than yards facing the east  or north. So, if you are handling a western or southern  slope, pick drought resistant shrubs or your water bills may go through the roof.
Ground cover will help: Although for regular areas, bare soil will be  adequate to grow a bountiful flowerbed; the story will be different with  sloping surfaces where the soil will dry up and erode quickly due to  the slant. Use ground cover plants such as Vinca, Sedum and Liriope  muscari for best results. 
Use good ol mulch: This is a natural and affordable way to deal with  soil erosion; also it helps to fertilize the soil. However, it is  certainly not a permanent solution as the soil will drag the mulch away  slowly, leaving bald spots in your  landscape. Another issue is the fact that dry and dead leaves, twigs and branches are not exactly a visually pleasing sight.
Choosing plants for your sloping yard 
Ornamental grasses: Local, ornamental grass varieties with their deep  reaching root system that spreads horizontally is ideal for controlling  erosion. Since grass is low maintenance, you will not have to worry  about fertilizing the ground. Some attractive ornamental grass species  include: 
Little bluestem 
Inland sea oats
Plains lovegrass
Texas beargrass
Estern woodland sedge
All of these grass varieties thrive when planted on hilly terrain. 
Ground cover plants: For a  slope that receives a fair mount of  sunlight; prostrate juniper should work just fine while for a shady  area, you might want to use creeping boxwood, also known as pachysandra.  Other ground cover plants include wintercreeper and periwinkle which  also flourish on hilly grounds.
The decorative varieties: Plants that can be used in different areas of the  landscape include:
California Privet: This is a tall shrub that can grow to a height of 10  feet and has a foliage width of almost 4 feet; the shrub grows in part  sun and part shade producing cream colored flowers. The plant is hardy  and drought tolerant so it's an ideal choice for steep slopes.
Japanese Spirea: This is another plant that is a fabulous choice for a  sloping yard; the deciduous shrub grows almost 6 feet tall with a  foliage width to match. The leaves grow in a riot of colors from rich  burgundy to bright green and every hue in between. The flowers are  equally beautiful, an eclectic mix of purple and pink. However, the  plant does need full sun and flourishes in warmer weather 
Verbena: With its airy stems, the shrub can be coupled with plants that  sport dense foliage. The plant is a superb choice for a sunny  slope  and works well as a foreground shrub. It grows about 6 feet tall with a  foliage width of 3 feet. Its drought tolerant and the purples flowers  can add a touch of color to your landscape.
Oleander: A favorite with homeowners all over, few plants can create a  Mediterranean ambience like Oleanders in white and pink. The plant can  grow tall to almost 20 feet with a foliage width of 12 feet. The flowers  bloom in bunches almost continuously and are available in a myriad of  colors such as yellow, white, pink, red and apricot. It's extremely  drought tolerant and easy to grow. 
You could also try growing hibiscus and roses on a terrace. Remember to water a slope; a drip hose will be more appropriate than overhead sprinklers.
Innovative planting ideas 
Bordered Tiers: Use boulders or  landscape timber to create the  appearance of tiers. When using timber, you will need to stick the  pieces together and drive a rebar through them to hold the wood in  place. Use glue to stick pavers on the timber and your tiers will be all  ready. Use plants such as day lilies, lavender or other flowering  perennial shrubs. You can use decorative stone or mulch to hold the  moisture in.
Planted slope: You could also use a combination of flowering  shrubs, evergreens and perennial flowers scattered all over the yard.  Alternatively, create neat rows of greens and flowers for a formal look. 
A flowing deck: You could also build a series of decks, each falling successively with the slope  of the yard. Try building a series of walkways and steps connecting the  decks. Use flowering shrubs and solar lighting to create an enthralling  ambience. 
Plant in basins: Another innovative approach is to chuck the traditional  rows of shrubs in favor of basin like formations. Each basin will serve  as an exclusive spot for certain types of plants. 
Completing the landscape 
To add the finishing touches to your  landscape: Remove the grass  and other growth from the areas designated for the walkway. Use gravel,  stone or any other type of hardscape material to cover the surface and  pack pea gravel or sand in between.
Use large boulders placed across the yard to create a natural and earthy  appeal; the large stones should be placed at the bottom of the  slope  away from the steep areas for safety. Once all the stones have been  placed as desired; bury them one fourth of the way into the ground, so  that you get stability along with a natural look.
Finally add the finishing touches with a fountain placed in a central  location, you could also use ornamental lights or antique wooden benches  or wrought iron furniture to complete the  landscape.