Rock Your Landscape With A Gravel Garden
They’re sustainable, low-maintenance, and help to conserve precious water resources. The gravel garden is a trend that is growing in popularity across North America. It is especially popular in areas in which water is scarce or is rationed during drought conditions. The additional benefits of not having to mow or be tasked with applying weed-and-feed annually are also attractive to many homeowners. Gravel fill is much less costly per square foot than other forms of hardscaping such as pavers, tiles, cement, asphalt, or flagstones, and it can be removed easily if the homeowner decides to return to turf.
What is a gravel garden? A gravel garden is a form of xeriscaping in which gravel is used in place of grass. The gravel is held in place with a bounding border. The gravel is interspersed with plant material that is drought tolerant and that thrives in a sunny situation. The gravel layer acts as a mulch, helping to retain soil moisture and keeping weed seeds from sprouting. It also provides a stunning contrast to the various hues of green in the garden. And if fine gravel is used along walkways, it is even possible to go barefoot without wincing.
Creating a gravel garden is similar to building a raised bed garden. The first step is to define the garden area and remove all of the turf. This can be done by using one of three methods: turf can be scooped up with a turf cutter, it can be killed off by covering the area with old carpeting or black plastic for at least a month, or it can be killed by spraying with a total-kill post-emergent herbicide. If using the herbicide, “scalp” the greenery by mowing it at the lowest possible setting before applying the chemicals. This will improve the rate at which the herbicide is absorbed and grass and weeds will die out quickly.
Once the turf is removed, turn the soil to a depth of at least 5 inches, and rototill in well-composted organic matter. If the soil is clay or drains poorly, then also rototill in an amendment like pelletized gypsum to help create a more porous environment.
Surround the freshly worked soil with edging. This can be an unobtrusive metal or rubber edging that is pounded into the soil or it can be a short wall constructed with brick pavers or wooden planks. The edging should be high enough to create a dam that will keep the gravel within bounds.
Once the edging is in place, it’s time to add the gravel. The base gravel should be fine – between 3/8″ and ¼” in diameter – and have no sharp edges. Gravel pits refer to these grinds as pea gravel, birds-eye gravel, and buckshot gravel. The finer the gravel, the softer it feels underfoot, and the easier it is for the gardener to kneel on when planting or pulling weeds. The gravel should be laid to a depth of 4 inches and raked using a gravel rake so that the top is level. Different kinds of gravel can be added to the garden; the finer grinds should be placed in the areas where plants will be installed, but a coarse grade, such as river rocks or a few large stones, can be used as accents. Some complex designs might include stones with dramatically different hues, geometric patterns, lush curves, and larger flat stones embedded in the gravel that are used for a walking path.
The plants are installed in the final step. Plant material should be relatively small; starter plants should be in 3 ½ to 4 ½ inch pots. This eliminates having to move a large amount of gravel aside in order to accommodate a spade. Before removing the plant from its pot, many landscapers recommend brushing off the top layer of the potted plant’s soil and removing it to a bucket or basket. This should remove any weed seed that may have embedded itself in the potting mix at the nursery. Weeds won’t be transferred to the new garden. Then, using a trowel, dig a hole large enough to hold the plant, backfill with soil to hold the plant firmly, and then gently rake the gravel around the plant until the gravel touches the crown. Perennials and herbs should be spaced 12 to 18 inches apart. Spring blooming bulbs such as small alliums or croci can be planted 6 inches apart in the fall.
After the plants have been installed, they should be watered in. Continue watering every 3 to 5 days until the plants are well established. After that, they only need to be watered when they appear to be thirsty.
To maintain the gravel garden, remove spent blooms and any dead plant material regularly. Use a leaf blower to move leaves and other light debris off of the gravel. Cut perennials back to a 6-inch height at the end of the growing season. Allow the annuals to self-sow. If any weeds emerge, pull them so that they can’t get a solid root hold. Feed blooming plants with a water-soluble bloom booster every other week throughout the growing season.
The following is a list of plants that are recommended for growing in a gravel garden:
Bulbs: crocus, allium
Annuals: portulaca, California poppy, lantana, cosmos
Herbs: English lavender, rosemary, creeping thyme, catmint, lemon balm
Perennials: echinacea, beebalm, black-eyed Susan, gaura, sea holly, lamb’s ear, most succulents, hardy cacti
Shrubs: yucca, juniper species, mugho pine, azalea, cistus
Vines: trumpet vine, morning glory, moonflower, grapes
If permanent plantings aren’t part of the landscaping plan, plant ornamentals in large patio pots and place strategically on top of the gravel. Add some water-holding polymer to the potting mix so that the water-saving benefits of a gravel garden can still be realized.
The gravel garden may be one of the greenest developments in landscaping. Even a few square feet devoted to a gravel garden can reduce water use and time spent doing maintenance tasks, leaving more time to enjoy the garden.
