|
David Salman, President/
Chief Horticulturist
Ava Salman, Marketing Director
Cindy Bellinger, Editor
Kerry Kirkpatrick, Web Design
| |
 |
Gardening on Hillsides
By Cindy Bellinger
A few years ago I visited a friend's farm in Ohio. Envy immediately crept in. Her whole place was flat. For those of us living in the Rocky Mountain region, we usually have hillsides that need to be dealt with.
Living on a mountainside for nine years has not only pushed all my muscles but my imagination as well, trying to create planting areas. But there are a few tricks to slope gardening that really help with the inherent problems.
Analyze the Site
 Water, whether it comes in streams, rivers or rivulets, always takes the path of least resistance. If you have a chance and the willpower, wait a year before reworking a hill. This allows you to understand the character of a slope and see how water naturally angles down its face. The information you'll gather is two-fold.
- You'll see the direction the water takes and be able to decide which areas need stronger reinforcements. And yes, you might consider getting out in the rain and marking the path with stakes. It's a little miserable at the time, but well worth it later. It's amazing how quickly you'll forget the path of small waterways when the rain stops.
- By noting the gathering places of water can supply you with ideas for garden designs. In the low lying places, consider using these natural basins for plants that like their roots a bit damp.
Making Barriers  If you want to terrace an area, there are many materials to use to "level out" a slope. The most common materials include--
- Brick
- Stone
- Landscaping cinder block
- Pressure treated wooden planks
If you can find untreated railroad ties (not easy!) that's a great way to go. If not, try 2x6 or 8" wide planks. These also can be cut them to fit angles and curvatures. Stabilize them with rebar on the downhill side. If you go up two layers with boards, before backfilling with dirt, line uphill side with geotextile (weed barrier cloth) to lessen seeping of soil and water under the bottom board and through the crack between boards. The drawback to using wood, though, is after awhile they'll begin to rot and will eventually need to be replaced. Using Plants for Stabilizing  Plants should be used to stop erosion by themselves and in combination with constructed barriers. Plants are especially useful to help cover-up and soften the look of constructed materials. Choose perennials with deep roots and groundcovers with spreading stems to hold the soil against erosion.
Perennials and Groundcovers
|
Shrubs
-
Rhus trilobata 'Autumn Amber' (Three Leaf Sumac) is a low-growing native shrub with flat growing branches that will spread quickly over an area.
-
Prunus besseyi 'Select Spreader' (Spreading Sand Cherry) is another native that works well as a large scale groundcover for sunny slopes.
-
Fallugia paradoxa (Apache Plume) is often found on slopes along highways, needs little moisture and is fairly deep rooted.
Grasses
-
Agropyron sp. 'Mora Blue' Blue Bladed Wheatgrass is an aggressive stoloniferous, western grass recommended to hold the soil in dry ditches, along the sides of road cuts and on slopes where it can be interplanted with colorful native wildflowers.
-
'Hachita' Blue Gramagrass roots go very deep after a year or so and makes a nice fill between flowers and shrubs.
-
'The Western Trails' Native Grass Seed Mix contains a superb mix of soil holding native grass species that is useful on sloping areas.
Another trick that David Salman suggests for hillside planting is to cut 4" deep rims off the tops of used 1, 2 and 5 gallon plastic containers. Push the rims into the soil around the plants and use them as watering wells for the first year. This helps the water soak more deeply into the soil where the roots will follow, instead of spilling down the hill where the plants can't use it.
Water Retention and Erosion Control
By Mary Ann Walz
Retaining water--rain or snow melt--is the primary way to prevent erosion of soil. In some places, local ordinances require this. Even without the force of a law, it makes good sense to do so. Plants benefit from the moisture and need the nutrients found in good top soil to ensure healthy growth. Many places have such shallow top soil that losses of even fractional inches are inevitable.
So how can you retain the water in place?
-
 One of the easiest ways to do this is through the use of a good cover of mulch on flower beds. The mulch softens the raindrops and helps absorb excess moisture so the water does not form a sheet and flow away.
- On slopes, even slight ones, a system of swales and berms slows the runoff and helps keep water in place. A swale is a slight depression made along the contour of the slope, while the berm is the raised area beneath the swale, also along the contour line of the slope. The swale will collect extra water and be a place where plants requiring extra moisture can be planted. When water is colleted in a swale, erosion will not occur.
- Adding good amounts of compost to planting areas will make the soil more friable and better able to retain moisture.
- Terracing on slopes make level planting areas where water will be retained to minimize erosion.
- Hard surfaces, such as driveways or parking areas, can create a great deal of runoff so the edges should be contoured to catch the runoff. This runoff can be used to advantage to make moister planting areas.
- Roofs also create an enormous amount of runoff. Catch this water in a rain barrel for later use as irrigation water or create piping or shallow ditches to move water by gravity to planting areas away from the house or building.
Plant Profile with David's Helpful Hints--Penstemon (Beardtongue)
 An essential plant in any xeriscape, the
Penstemons are unsurpassed in attracting hummingbirds to your garden. For beginning gardeners, we recommend growing a few of the easier species such as--
Because many Penstemon species are adapted to grow in harsh Western habitats, it is important to keep a few cultural considerations in mind when bringing them into our garden.
-
 They don't like clay soil so plant in only in well-drained soils, avoiding rich soils. Too much compost can shorten their life span. Avoid compost rich soils and tight clay soils.
- Plant high, leaving the top of the rootball just above the surrounding soil to avoid burying the crown of the plant. It needs to dry out and not sit in soggy soil.
- Avoid bark, grass clippings or compost as mulch materials. These mulches are detrimental to healthy Beardtongues. They hold moisture around the crown and will also cause disease in wet, cold weather. It is better to leave them non-mulched or use gravel.
-
 Allowed to re-seed; Penstemon will sometimes lives for only 2 or 3 years (e.g., P. palmeri). To keep them going longer, let some of the plants set seed (don't deadhead them). The volunteer seedlings will be more vigorous and longer lived than the original parent plant.
- Fertilize sparingly. Beardtongues like "tough love" and need only to be fertilized once each year in the fall. Apply a light application of an organic or natural fertilizer. Yum Yum Mix, with its high trace mineral and phosphorus content while also being low in nitrogen, is an excellent fertilizer for these and other native plants.
Plant Combinations for Great Garden Designs
 This flowering plant, grass and succulent combo creates a nice pinkish area in your garden, adding a touch of cultivated wildness.
Oenothera caespitosa White-Tufted Evening Primrose is a widely distributed low-growing western wildflower that's a delight in the xeric garden. It sports bright pink buds and huge white four-petal flowers. Grow in full sun with dry, infertile well-drained soil conditions and give it room to spread. Mulch with crushed gravel. Zones 4-9
Nasella (Stipa) tenuissima Silky Thread Grass. One of our most graceful and shimmering native grasses, Nasella thrives in full sun spots with tough, not-so-good soil conditions. It lights up when the late rays of the afternoon sun can catch its silky plumes and will sway gently in even the slightest breeze. Flowering in early summer, it keeps looking good from fall through the dead of winter. Zones 5-8.
Delosperma cooperi Hardy Purple Ice Plant is a fine South African introduction, valued for its shimmering fuchsia purple daisies that keep coming all summer. A vigorous spreader, it forms a dense mat of succulent, linear green leaves, in any well-drained soil. Stop watering in mid-fall to harden for winter. This plant has become a staple in xeric gardens. Right at home on top of gravel mulch; it helps to cool down these hot areas. Zones 5-10.
Garden Glossary — terms for the horticulturist.
Annual: Plants that complete their life cycles from germination to seed in a single growing season.
Chlorotic Foliage: A condition in which the leaves of a plant turn yellow. An iron deficiency in the soil or lack of oxygen to the roots caused by over watering is usually the cause.
Crown: The part of an herbaceous perennial at or just below the soil level where the roots converge to form woody tissue from which the buds for new stems grow.
View our Entire Garden Glossary
High Country Gardens Library
Monthly Ezine Gardening Tips
|
Choose perennials with deep roots and groundcovers with spreading stems to hold the soil against erosion.
