This article comes from one of our favorite customers, Chris. He loves to experiment with fun new varieties of perennials and always impresses us with his ever-expanding Crevice Garden! Thank you Chris for sharing these great ideas, insights, and gorgeous pictures with us!
At one time or another you have probably come across a bunch of really cool small perennials at your local nursery that you’d love to adopt and plant but have no idea where to put them in your garden that they wouldn’t get lost or trampled.
Several years ago, I decided to dedicate an area of the yard to where we could plant small perennials, but I had no idea how to do it or even if it would work. While researching on the internet I saw some really great ideas and techniques, but one really caught my eye, crevice gardening.
Crevice gardens are a rock gardening technique that was first developed in the Czech Republic. What makes crevice gardening stand apart from traditional or English rock gardening is that the rocks are buried vertically and mimic the conditions found in alpine climates which allow the gardener to grow plants you wouldn’t otherwise find in an urban garden at lower elevations.
Placing the rocks vertically and close together makes small micro-climates for the plants where they will thrive. A great example is the common dandelion. Have you ever been walking down the sidewalk and seen a humongous dandelion growing up from between the cracks? Looking around you notice more dandelions off to the side in the grass but they’re only a fraction of the size of the one in the crack. That’s because that crack is forming a micro-climate for the dandelion where it is free to do its thing with little or no competition from other plants for nutrients and water.
Large flat rocks like sandstone pavers or large pieces of flagstone are frequently used in this type of gardening although that is completely up to you and your imagination. The rocks should be placed anywhere from half an inch to three inches apart. Some rocks should be offset or staggered to create the occasional pocket for placing a larger plant. Crevices in between the rocks should be at least 12 inches deep or more. In most cases about 90 percent or more of the rock is going to be buried so don’t get too worked up if there are large blemishes on the surface of the rock while picking materials.
When planting in the very narrow crevices of the garden, one inch or less, the root ball of the plant should be soaked in water until most of the dirt has been removed while being extremely careful not to damage the tap root. A small hole is then made in the dirt with a small trowel or hori-hori tool and the roots are carefully pushed down and fanned out into the hole with a small diameter dowel or chopstick.
For larger crevices, remove the plant from the container and score the root ball with the tag or knife as you would any other plant to prevent them from becoming rootbound. Decide which way you want to orient the plant in the crevice and then fan some of the roots out on opposite sides of the plant. Place the plant in the hole with roots paralleling the crevice and back fill. Plants found in two-to-four-inch pots are the ideal size for most of these applications.
Another cool thing about crevice gardening is that depending on the orientation and height of the stones sticking out of the ground, you can plant full-sun, part-sun or shade plants in the same area. For instance, if the garden is oriented north to south with the crevices going east to west you can have a full-sun plant on the south side of a stone and a part-sun or shade plant on the opposite side of the same stone so long as it is sticking out of the ground far enough to provide full or partial shade.
The crevices between the rocks are typically covered in pea gravel anywhere from half an inch to one inch deep directly on top of the dirt without the use of a weed barrier. Because of this you will need to take a good look at your crevice garden once a week to pull out any new weeds or unwanted seedlings. Remember that dandelion? Weeding is also something to keep in mind during construction. Don’t make any part of the crevice garden inaccessible. Larger stones should be incorporated into the design not only to break up the lines and make it look more natural but also for access to different parts of the garden without having to do gymnastics or parkour to pull a weed.
Luckily, we live in Colorado which by some accounts is quickly becoming the crevice gardening capitol of the United States. There are many online resources to inspire you and numerous crevice demonstration gardens throughout the state to include an amazing example at the Denver Botanical Garden.