No, this isn’t an X-rated post about steamy things going on in the garden. Intermingling is a new term in horticulture, a mix of ecology and garden design. I first heard the term a week ago at a talk by Thomas Rainer at the International Master Gardener Conference in Portland, OR. I attended his lecture out of curiosity, knowing nothing. I came out having had an almost spiritual transformation. He gave an inspirational talk. Intermingling in the garden refers to designing lush plant communities which mimic the wild places we are rapidly losing. It is about designing plantings that look and function more like they do in nature, more robust, more diverse, and more visually harmonious while requiring less maintenance. For those of us who have spent hours weeding mulch, this was an “ah-ha” moment. In nature plants richly cover the ground, any bare spots are quickly overgrown. So, why not design for that overgrowth? In his book Planting in a Post-Wild World Mr. Rainer proposes designing with plant communities that link nature to our landscapes, that bring together both ecological planting and traditional horticulture. The focus on layered plantings means that there can be more beneficial plants in small spaces. What does he mean by layered planting? He suggesting thinking of garden design in three vertical layers. The upper design layer would include those plants that create color and texture. The lower layers, that may stay hidden, provide essential erosion control, soil building, and weed suppression.
- Structural layer – tall species that tower over other plants, this would include tall grasses as well.
- Seasonal theme layer – plants that create color and texture at certain times of the year. These plants are placed as they would be in nature, not all in drifts.
- Ground cover layer – those plants that occupy the lower layer of grassland communities. They generally have shallower root systems that do not compete with the deeper roots of tall plants.
Although this is a fairly new concept here, gardens in the U.K. and Germany are already being designed this way. And in many cases they are using our own native plants because of the enormous diversity of species in the U.S.
Another book which explores this idea is Planting, a New Prospective by Piet Oudolf. I have it on order. Mr. Rainer mentioned Piet Oudolf in his talk. The description sounds perfect for helping design the Fort Bragg garden since we are starting from scratch. “Planting: A New Perspective is an essential resource for designers and gardeners looking to create plant-rich, beautiful gardens that support biodiversity and nourish the human spirit. An intimate knowledge of plants is essential to the success of modern landscape design, and Planting makes Oudolf’s considerable understanding of plant ecology and performance accessible, explaining how plants behave in different situations, what goes on underground, and which species make good neighbors.”
We spent the weekend in our Fort Bragg garden, using a pick ax to break through the compacted soil to create a garden bed. I don’t think that soil has ever seen a speck of compost, it soaked it up like it was dying of thirst. It is not the ideal time of year to be doing this, grass seeds are going to sprout when I water the soil. They will need to be weeded out before I plant. But, we have to work with the time we have and those irises need to go in before the rain starts this fall. Meanwhile I am researching plants to intermingle. I do think there is a role for mulch as far as moisture preservation, especially in drought torn California and before the plants are established.
The garden has a long way to go. Gardening is a patient occupation that often takes years to see results. Hopefully my back will hold out.