Gardening Sweet Spots
By Donna Hessel
Why a Rock Garden?
If you have a difficult area on your property—a slope, too much lawn to maintain, an area where nothing will grow, beds or walkways that need to be defined; or just a small area needing a focal point—consider adding a rock garden. Well-designed rock gardens are low maintenance and enhance the landscape year ’round. Rock gardens connect manmade landscapes to nature.
How to Build a Rock Garden
Choose the location. Consider the elevation. Is it sloped? Does soil need to be added and mounded? How much sun does it get? Will plants need regular water? Is it visible from the street or from a window? What surrounds the area?
Design the garden. Draw a rough sketch. For a very large area, consulting with a landscape company may be beneficial, especially if large boulders are to be included in the plan. Rocks larger than about 12”-14” are too heavy to move without some kind of equipment. Plan to use materials in proportion to the house and yard – larger rocks in a large area; smaller rocks in a small space. Create an appearance that complements the house style. Rough, irregularly-shaped rocks add a rugged look; smooth, small rocks or white gravel provide a more formal look. Vary the size and shape of the rocks. Use a variety of materials for color and contrast, but don’t mix too many to avoid a “busy” appearance.
Terraced rock gardens are very effective in keeping soil from eroding on a slope, while adding beauty to the landscaping.
Keep it natural. A few well-placed, large rocks will create focal points and anchor the space. Be sure to allow planting/growing space between rocks. Smaller rocks or pebbles can be placed around the larger rocks. Set large stones one-third into the ground, not plopped on top. Random groupings of rocks look more natural than straight lines or patterns.
Adding a water feature, stepping stones or perhaps shells or a cairn, will enhance the design.
Check online markets (e.g. Face Book and Craig’s List) for bargain priced materials. Other possible sources include construction sites, leftover materials from another landscaping project, the city’s recycling center or farmers’ fields.
Select the Right Plants
Source materials. Large size rocks or boulders will have to be purchased from a landscape company that will transport them and place them where the design specifies.
Choose plants that will thrive in the soil in the garden and in the climate. Alpine plants need sandy soil and good drainage; ferns and hostas need richer soil and more water. Smaller plants will make the rocks the stars of the garden. Perennials, ornamental grasses, and small shrubs can add height. Ground covers soften the overall appearance. Narcissus, species tulips and alliums add spring color. Mosses, ferns and hostas work well in a shady area. Consider the color of the rocks and choose plants with colors that complement the rocks. Vary upright and creeping plant materials. Plants selected should have similar water and sunlight requirements. Variation in height and leaf texture will add visual interest.
Plants for Rock Gardens
For sunny gardens:
- Ground covers such as sedums, succulents, creeping thyme, snow-in-summer (Cerastium), creeping phlox, gold alyssum (Aurinia), ice plant (Delosperma)
- Perennials such as sedges and small ornamental grasses, dwarf conifers, dianthus, rockcress (Aubrieta),columbine, speedwell, lamb’s ear, bellflower (Campanula)
- Bulbs such as species tulips (deer resistant!), narcissus/daffodils, crocus, squill, reticulated iris, alliums
For shady gardens:
- Ground covers such as creeping Jenny, mosses, ajuga, dead nettle (Lamium), vinca, sweet woodruff
- Perennials such as ferns, coral bells, hostas, hellebores, astilbe, lungwort, columbine, barrenroot (Epimedium)
- Bulbs such as snowdrops, narcissus/daffodils, muscari, squill, crocus, anemone, tuberous begonias, caladium
Planting and Maintenance Tips
Arrange plants in the garden while they are in their pots. Grouping three of the same plant together will provide a cohesive look. Add soil and decorative rocks as you plant. Adding rocks around the plants as you plant will make them look more natural, like they have grown up through the cracks in the rocks. While rock gardens are generally low maintenance gardens, some regular attention to them is required. Rocks in a sunny area absorb heat. Plants can dry out quickly and will need water, especially during dry weather. Research the amount of fertilizer your selected plants need. Some, such as succulents and alpines need little or none; coral bells and hostas need some nutrients. Ground covers and pebbles or gravel will keep weeds at bay, but young gardens will need to be weeded occasionally until plants fill out the garden. Prune out dead growth and spent flowers for a neat appearance and to promote new growth.
No Room for a Big Rock Garden?
Create a miniature rock garden in a container. Hypertufa, made from equal portions of Portland cement, peat moss, perlite or vermiculite and water, make excellent containers for miniature gardens. Succulents live very well in hypertufa pots. (Learn how to make one at gardeners.com/how-to/hypertufa/.) Hypertufa containers can be made any size, but any shallow container would also work well. Just make sure it has a drainage hole.
A Dry Stream Can be a Rock Garden
A dry stream serves both as a rock garden and natural drainage. If rainwater runs through the property to a storm sewer, a shallow dry stream containing a variety of rock sizes and shapes can slow down and direct the water during a rain storm and act as a rock garden during dry periods. Water-loving plants, such as iris, grasses and ground covers, can be added among the rocks in the stream or along the edges.
With some imagination and advance planning, a rock garden can be added to most properties to add variety and interest to the landscape.
Resources
Garden Design online newsletter – “Rock Garden Ideas, Design and Plants” by Janet Loughrey, Garden Writer & Photographer
The Spruce – Thespruce.com/how-to-build-rock-gardens-2132674 and
“How to Get Free Rocks for your Garden: 11 Best Ways” by Erin Huffstetler
thepioneerwoman.com/home-lifestyle/gardening/g46935075/rock-garden-ideas/
Photos from pexels.com
