Design Elements

Trees – the foundation of your design


  • Trees provide shade to plants reducing their need for water as well as providing cooling for sections of a house.
  • Use deciduous trees on the east, south and west sides of the house. These will provide shade during the summer and allow sun to come through bare branches during the winter.
  • Use evergreens for screening.
  • Most trees need full sun.
  • Choose the tree color or variety according to the site location. Tree color considerations are bark, spring color, fall color, flowers and berries.
  • When planting trees, amend the soil to 2-3 times the root ball. Remember to remove the burlap and wire mesh when planting.
  • Don’t plant trees in areas that are smaller than 10 feet wide. Do not plant large trees closer than 10 feet to the house / structure due to root invasion, potential branch damage and fire prevention.
  • Space trees according to their size at maturity. Many trees will grow smaller than the mature size listed in books due to Castle Rock’s altitude and short growing season.
  • Consider the size and shape of trees. Upright evergreens are a good choice for added structure and come in a multitude of colors.
  • Typically, after establishment, trees should be watered about 15 gallons per inch of trunk diameter twice per month. The water should be applied at the drip line (the area of soil directly underneath the tips of the branches) extending about 5 to 10 feet beyond the drip line. This is commonly accomplished by converting an automatic spray irrigation system to a drip irrigation system that delivers water to the drip line and beyond.
  • Mulch with wood or bark to a depth of 4 inches. Keep the mulch 6 inches away from the trunk to prevent any moisture or mildew conditions. Plant sparingly under a tree as added moisture may produce trunk rot.
  • Using rock mulch may produce too much heat for the tree, causing the soil to dry out.

Shrubs – the landscape background


  • Plant shrubs outside of the drip zone of trees.
  • When using a shrub as a focal point, splurge on a bigger specimen.
  • Don't over plant woody shrubs. Overcrowding creates irregular growth and greater potential for disease. Be mindful of mature height and width when planning your garden.
  • Shrubs planted in mass are ideal for screening or dividing areas.
  • Some shrubs can be left alone for an informal look or pruned to be a focal point.

Grasses – provide texture and balance


  • Ornamental grasses, which are not meant to be mowed, provide seasonal interest with distinctive sprays and seed heads.
  • Grasses are ideal for creating height and texture to a design and are planted as a backdrop to perennials and annuals.
  • Favorite grasses for Castle Rock: 
    • Karl Foerster is a durable standard that can be found in many commercial spaces; 
    • Another recommendation for residential spaces that has a softer, more flowing look is Miscanthus.

Perennials and Annuals – add color


  • Perennials are herbaceous plants that come back every year. However, if the perennial is not winter-hardy, it could die at the end of the season and not grow back.
  • Plant perennials in front of the shrubs with the smallest ones in the front.
  • Use perennial flowers in close groupings to create a powerful effect. Grouping also keeps plant roots cooler and can reduce the need for water.
  • Annuals are great for seasonal summer color and should fill in bare areas. Annual color is often achieved using planters and flower pots.
  • Choose flowers not only for their interest and color, but if they attract birds and butterflies.

Ground Covers – a versatile plant


  • Plant ground cover in front of perennials and shrubs.
  • Ground covers can replace turf in low traffic areas.
  • Ground covers can be planted in the joints stone patios that are set in sand for a soft effect.
  • Plant ground covers on steep slopes and hard to water areas.
  • After becoming established, ground covers require minimal water.

Vines – arbors create structure to a yard


  • Use arbors to create interest, block views, and build useful areas.
  • Vines take 2 to 3 years to become established.

Lawns – have a place in every landscape plan


  • Reduce the size of the turf lawn. If you use part of your lawn, keep it!
  • Castle Rock Water does provide a rebate for removal of high-water use turf. Learn more about our rebate program.
  • Install shade trees to provide shade for turf areas, reducing the need for water.
  • Look at options depending upon your use. Kentucky blue grass is the typical lawn and requires 25 inches or more of water per season. Buffalo grass, a native to Colorado, is a beautiful soft blue-green color and takes less than half the water of blue grass. Fescues and Blue Gama are other options for turf grass.
  • Favorite turf lawn for Castle Rock: Fescue, which is has finer blade than Kentucky bluegrass and takes about 25 percent less water.

Rocks – as a design element


  • Grouping boulders can add visual interest and often ‘ground’ a flowerbed.
  • Group various sized boulders. Think about how they appear in nature.
  • When using gravel and rocks, consider using different sizes and colors in different places. A well designed space should not be a sea of rock.

Mulch – the finishing touch


  • Coordinate shape, color and function of your mulch with the plant types, trees and house color. For instance, use angular rocks on slopes and do not use rock mulches next to trees.
  • Mulches keep the soil cooler, reduces evaporation and minimizes weeds. You may need to fluff organic mulches to maintain air and water movement to the plant.
  • Organic mulches includes wood chips, chunk bark, shredded bark, pine needles, lawn clippings and straw. Organic mulches tend to provide nutrients for the soil, but will need to be replaced periodically. They should be 4 inches deep. In addition to having to replenish organic mulch, it can also blow away. Keep in mind, when installed directly onto the soil, verses on landscape fabric, mulch tends to adhere better to the soil, reducing loss from wind and run-off.
  • Inorganic mulches are stone-based and include rock, cobblestone, pea gravel, lava rock and crushed rock. They last longer than organic mulches, don’t blow away and many low hydro-zone xeriscape plants prefer gravel mulch. Apply 2 inches deep.
  • Rubber mulch is not recommended for planting areas as it can potentially leak harmful chemicals into the soil.
  • Do not install plastic landscape sheets as they will reduce the amount of air and water to plants. Landscape fabric can be used as a weed barrier, but it may reduce the growth and spreading of plants.
  • Douglas County provides a Slash Mulch Program where residents can drop off tree limbs and shrubs to be mulched and to pick up free wood chips.