A hillside or sloped yard can challenge even experienced gardeners. Steep slopes planted with turf grass are difficult and potentially dangerous to mow, but many communities have ordinances against un-mown front yards. Slopes and hillsides also often have problems with erosion, and because of that may have thin soils that cannot host many plants. Depending on the size and steepness of your hillside, you could consider a retaining wall, terraces or growing hillside-friendly plants.
If your front yard has a medium-grade slope, you can consider building a single retaining wall along the edge and filling the space behind it with more soil to create a more level planting area. Retaining walls can be constructed from brick, decorative concrete blocks, dry laid stone or mortared stone. Retaining walls that are less than four feet tall are the most visually appealing—and also the safest in case anybody falls over the edge.
Terraces are a essentially a series of short retaining walls (usually one to three feet in height) to create stepped gardens in a very steep sloped yard. Flowers, herbs, vegetables or small shrubs can be planted in the spaces created by terraces. Avoid planting trees, large shrubs or other plants with extensive root systems, as the roots may disrupt the terraces.
If you choose to keep the natural slope in your front yard, you'll have a few more options when it comes to planting. In general, a variety of trees, shrubs and perennials works better on a hillside garden than a monoculture of ground-cover, because a mixture of plants will have varying root systems that will hold the soil in place more effectively to prevent erosion. Native plants are good choices, because they have evolved to grow in your local area.
Planting turf grass on a slope often worsens erosion because turf grass is very shallowly rooted. If you really want the look of turf, consider a "no-mow" short native grass mix, and plant a few shrubs or perennials on the slope, too. According to Las Pilitas Nursery of San Diego, California, laying straw or landscaping fabric on a slope will only control erosion for a very short period and will, over time, make the slope more susceptible to weeds.