You don’t need dirt to have a green thumb. It turns out, you can grow a pretty wild garden in a few cups of gravel. Here's how.
WASHINGTON — You don’t need dirt to have a green thumb. It turns out, you can grow a pretty wild garden in a few cups of gravel.
Richard Campbell, of Ellicott City, Maryland, has been gardening sans soil for more than 20 years — ever since he witnessed a watermelon vine growing out of rocks in his uncle’s yard. Campbell formulated a theory that the rocks were feeding nutrients to the watermelon, and has been researching geological agriculture ever since.
Now Campbell is the author of “River Stones Grow Plants” and founder of To Soil Less, a company that educates schools, communities and government agencies on the science and benefits of gardening in gravel. He showed WTOP how to grow a produce section in a few plastic cups. But before you begin, there are a few things to note:
Any old rock won’t do. Campbell said river rock, which you can find bags of at Ace Hardware or other home improvement stores, is the type one needs to use to grow a garden. It’s a sedimentary rock, which Campbell said feeds nutrients to the plant.
Sand is the secret ingredient in a gravel garden. It acts as the irrigation system, retaining water for the plants.
Outdoor gravel gardens require a different setup and configuration than indoor gravel gardens, including a layer of agricultural fabric between the rocks and the sand. The following steps are just for indoor/windowsill gardens.
Step 1: Set up your gardenYou can set up a gravel garden using a clear plastic cup or any recycled soda bottle or milk carton you have around the house. (Just make sure to cut a taller plastic container down if that is what you end up using.) Using a thumb tack, poke holes in the bottom and around the side base of the cup. These holes allow excess water to drain out and then enter from the drip tray once the sand dries out.Add about ¾ to 1 inch of sand at the bottom of the cup. This acts as the irrigation system. When the cup is watered, the sand retains the water and releases the moisture as needed.
(WTOP/Rachel Nania)
WTOP/Rachel Nania
Step 2: Add rocks Fill the cup about halfway with river rock.
(WTOP/Rachel Nania)
WTOP/Rachel Nania
Step 3: Add seeds Then add a few seeds of your choice on top of the rock. Based on results from Richard Campbell’s demonstration, microgreens and peas do well in gravel garden cups.
(WTOP/Rachel Nania)
WTOP/Rachel Nania
Step 4: More river rock Then fill the remaining space in the cup with more river rock.
(WTOP/Rachel Nania)
WTOP/Rachel Nania
Step 4: Water Place a drip tray or larger bowl under your plastic cup and pour water over the gravel garden. The excess water will drain out of the cup and sit in the drip tray; it will be used up by the garden as it dries out. Experienced gardeners will find that gravel gardens need less time and attention when it comes to watering. Campbell said they need to be watered about once a week.
(WTOP/Rachel Nania)
WTOP/Rachel Nania
Step 5: Sit back and watch it grow Place your garden under lamps, on the porch or in a sun-filled window and watch it grow. Depending on the seeds planted, Campbell said gravel gardens tend to yield results faster than traditional soil gardens. Because of this, his hope to is one day see families have gravel grow stations in their homes that serve as a “permanent produce department.”
Pictured: Gravel gardens two weeks after planting.
(WTOP/Rachel Nania)
WTOP/Rachel Nania
Campbell said river rock feeds nutrients to the plant. In this picture, you can see the plants roots extend through the rock and into the sand. This garden contains no soil.
(WTOP/Rachel Nania)
WTOP/Rachel Nania
Campbell holds a tomato plant growing from a gravel and sand garden in his Ellicott City, Maryland, home.
(WTOP/Rachel Nania)
WTOP/Rachel Nania
Campbell holds a bean plant growing from a gravel and sand garden in his Ellicott City home.
(WTOP/Rachel Nania)
WTOP/Rachel Nania
Campbell is the author of “River Stones Grow Plants” and founder of To Soil Less, a company that educates schools, communities and government agencies on the science and benefits of gardening in gravel.
(WTOP/Rachel Nania)
