Crevice Garden Building Workshop by Nancy Shepard

 

Crevice garden at the Denver Botanic Gardens Photo: Denver Botanic Gardens

I recently attended a crevice garden building workshop put on by Plant Select® and hosted by CSU. Plant Select is a non-profit collaboration of Colorado State University, Denver Botanic Gardens, and professional horticulturists (https://plantselect.org/.) The workshop was part of a two-day Plant Select conference specifically for landscape professionals. Landscape companies are increasingly using plants from the Plant Select collection because they flourish with less water and are tough and resilient in challenging climates such as our Rocky Mountain region. They told me they also have been getting more requests from their clients to build crevice gardens. CSU supplied the large bare expanse of an ugly eyesore outside the doors of the Colorado State University Horticulture Center.

"Before" photo of planting area outside of Colorado State University Horticulture Center Photo: Google Maps

This workshop featured Kenton Seth who I had heard talk at the 2023 Plant Select Conference. Kenton is well known as a crevice garden guru who also happens to live in Fruita, CO. For details about Kenton see the end of this article.

Within just five hours, the workshop participants built seven crevice gardens with different types of materials such as red flagstone, rip rap and even the remnants of someone’s concrete driveway. Plant Select arranged to have tons of a soil mixture called “Goldilocks” that consisted of sand, breeze and a small amount of compost (10 %.) Note that it is a very porous and gravely mix unlike the soil in our yards.

 

Team building a crevice garden from flagstone. Photo: Nancy Shepard

While I won’t try to summarize all the steps in building a crevice garden (see more resources below,) I’ll share a few key take-always for me:

Recycled dyed concrete

Recycled dyed concrete. Photo: Nancy Shepard

One of the crevice gardens was built using recycled dyed concrete. Kenton told the story of a client who had just had her backyard concrete patio demolished to make way for new landscaping. The pile of concrete sat in the corner of her yard waiting to be hauled away. Kenton saw an opportunity for the client to save money – use the broken concrete and avoid paying for crevice building rock to be delivered. Ross Shrigley, director of the Plant Select organization, described how he dyed pieces of demolished concrete by using “Reactive Concrete Stain.” He had already experimented with the technique several years ago and said the stain has not faded on those pieces he tested. He said you can continue to apply the dye after the crevice garden is built by spraying undyed areas as they lay in the ground. Here’s a picture of Kenton and the completed stained concrete crevice garden that a team created.

Kenton talking about the recycled concrete crevice garden built by workshop participants. Photo: Nancy Shepard

Bare root planting

Kenton demonstrating bare root planting. Photo: Nancy Shepard

When it came time to start planting in the crevice gardens, Kenton told us about bare root planting, the only way he does planting now. He said plants adapt faster to their new soil, especially the plants typically planted in rock and crevice gardens because the potting soil they are started in is not the type of soil they can thrive in. To see a great video about bare root planting, hear Grace Johnson, a horticulturist at the Denver Botanic Gardens: https://youtu.be/4E4d_Rw2zes.

Photo: Denver Botanic Gardens

The key advantages of crevice gardening are more plants and less watering. Here is an illustration from Kenton's book, "The Crevice Garden" showing how crevice plants grow deep into the crevices. 

In the crevice garden, a wide range of plants can be offered a variety of positions for both their tops and roots. Illustration by Kenton Seth

It's Ok to break the rules

Several times during our day long workshop, Kenton would remind us that it is Ok to break the rules. If you see crevice building instructions that have specific rock alignment or specific size gaps between rocks, that doesn't mean you have to do yours like that. He encouraged us to experiment because building crevice gardens is a creative process that evolves as it progresses.

Team building a crevice garden out of rip rap stone. Photo: Nancy Shepard

More about Kenton Seth

Kenton is a Colorado-based garden designer specializing in crevice gardens, xeric native and meadows. Kenton worked in public horticulture at a local botanic garden for ten yeas and then in the nursery trade for several more before starting his design/build company, Paintbrush Gardens in 2013. He writes for a variety of local, national, and international magazines and travels to lecture, from across town to across the seas. For more information see his blog: https://kentonjseth.blogspot.com/ 

Resources to learn more about crevice garden building

https://arapahoe.extension.colostate.edu/2024/05/02/gardening-in-the-cracks/ 
https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=55202
https://extension.psu.edu/crevice-gardens-life-between-the-cracks
https://gardens.duke.edu/garden-talk-060123
https://www.fortlewis.edu/fort-lewis-college-news/news-detail/where-the-orostachys-iwarenge-grow

The Crevice Garden: How to make the perfect home for plants from rocky places by Paul Spriggs and Kenton Seth

https://www.filbertpress.com/our-books/the-crevice-garden