Garden Talk: Gravel Gardens

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• Gravel Gardens Are Low-Maintenance, Drought-Resistant, Horticulture Expert Says

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  There are a lot of different types of gardens to choose from, but the best are those that thrive in the growing conditions of a given location and that minimize the need for maintenance.

  Jeff Epping, the director of horticulture at Olbrich Botanical Gardens in Madison, said there’s one type of garden he’s become enthusiastic about that fits that criteria but isn’t well-known in the United States: the gravel garden.

  Epping said that he was first introduced to the gravel garden concept by Wisconsin gardener Roy Diblik, whom Epping describes as “an incredible plantsman.” Diblik himself saw gravel gardens at the Hermannshof Gardens in Weinheim, Germany, and recreated the concept at his Northwind Perennial Farm near Lake Geneva.

  After visiting Diblik’s farm, Epping became fascinated with gravel gardens, and in 2009, with Diblik’s help, the first of its kind was installed at Olbrich. Since then, three more gravel gardens have been added, with the largest one to date getting finished on Thursday.

  In addition to increasing the number of gravel gardens at Olbrich, Epping said that he is also helping to install them on land owned by the city of Madison. Diblik is doing the same in Chicago. Especially for when money for maintenance and labor is scarce, Epping thinks that these gardens present a great solution for greenery.

  “This is a concept I’m absolutely sold on,” he said. “I think it’s the wave of the future.”

  There is no limit to the ways that gravel gardens can be designed, but Epping said that the key to success is to choose very drought-tolerant plants. The ideal specimens are those that, “once they are established, are good on their own, without additional water” he said.

  “You don’t fertilize, and weeding is very minimal,” he added.

  Another bonus is that gravel doesn’t degrade or decompose like mulch does.

  According to Epping, the big advantage to having a gravel garden is the promise of low maintenance in the future.

  “I never say ‘maintenance-free,” he said, “because there’s nothing life that’s maintenance-free … but for the most part, it is one of the easiest gardens that we have maintained at Olbrich, and one of the most beautiful.”

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  How To Install Your Own Gravel Garden

  Epping said that gravel gardens are certainly within the reach of most home gardeners.

  When a garden is first installed, Epping warned, it may look pretty sparse.

  “It’s a sea of gravel with a few dot of plants around,” he said. “But after two or three years, it’s just a solid mass of plants.”

  The slideshow above contains photos provided by Epping, and the Houzz web site has a gallery of user-submitted photos of gravel gardens for those looking for ideas and inspiration. In the meantime, however, here’s a general outline from Epping for amateurs who are interested in installing a gravel garden of their own.

  1. Create a border around an area that will contain the gravel.

  Epping said that treated wood is a fine option. He stressed that the border is critical because the gravel needs to be kept at a consistent depth throughout the garden, “right up to the edges.” If it tapers off at the edges, weeds will find a way in.

  2. Install the gravel.

  For a larger area, Epping suggested marking stakes with the desired depth and placing them throughout the garden to again ensure consistency.

  Start with 4 to 5 inches of gravel — a depth that will prevent weed seeds from germinating. Pea gravel is a good type to use, but Epping said the most important thing is that the gravel is of the same size, “so it doesn’t pack tightly,” he said.

  3. Begin planting.

  Epping recommends using plants that are in quart-sized pots, which happen to be 4 or 5 inches deep. Remove the plants from the pot and peel off the top inch of soil from the root ball — a trick Epping said he learned from Diblik for getting rid of weed seeds that have settled on the surface.

  Loosening up the root ball is the final step before planting in a hole made right in the gravel. Epping said that the plant doesn’t need to be sitting on the underlying soil, but it should be within an inch so that the roots can reach it with a little growth. Then, the final step is to fill the gravel in around the plant.

  Epping cautioned that dirt should be kept in as small an area as possible when planting: “You want to keep the organic matter from building up in that gravel,” he said.

  4. Maintain the garden.

  Besides the planting medium, Epping said that there’s other organic material to watch out for that should stay out of the gravel — for example, spent foliage from the previous season. While staff at Olbrich like to leave the plants up through the winter for visual interest, they are careful to cut the plants back to the gravel level and clear it all out first thing in the spring. Rakes and blowers are both useful tools for getting rid of every shred of organic matter that might get caught in the gravel.

  A second important element of maintanence is watering. While the goal is to water very seldom once a gravel garden is mature, Epping said that in the first season, frequent watering is actually key to help the plants get established. He said that for the first six or eight weeks, daily watering might be needed.