There’s an adage that says that if you really want to learn something, teach it to someone else. That’s what I’m doing here – I’m trying to get more deliberate and articulate about designing gardens, so I’m writing this about this next design exercise in a lot of detail, for my own education. Bear with me!
On the next street is a well-tended house with immaculately groomed garden beds. Even in the winter, they look trimmed and tidy. I wondered if you could replicate this groomed look with native plants and thought it would be a good exercise.
I don’t remember what they have planted here, other than the blue hydrangeas and a couple of small shrubs. But for the purpose of the exercise, I am going to pretend I’m starting with a clean slate, just a white picket fence about 3’ tall with a brick walk on the right (as seen from the house) and a cleared garden bed 3-4’ deep and maybe 24’ long, and in full sun. Something like this, which I drew in PowerPoint:
The main aesthetic goals here are to have good flower blooms for the June – August summer period, and to have the garden appear neat with only moderate maintenance. Ecologically, the space is in full sun and gets watered along with the adjacent lawn, so has at least a moderate level of moisture, and has soil that is probably at least part loam. The goal is to attract pollinators by using native plants, but we want to see each individual plant or group of plants distinctly. In other words, this should be a traditional planting style, and it will be OK to use some mulch. I think of this as a relatively easy first step for traditional gardeners moving towards more ecological practices.
Initial Concept Design
In a clean-slate space like this, all the planting design handbooks say to start with the structural plants. These are the plants that will sub-divide the space into smaller sections that can be then filled with plants of seasonal interest. The structural plants are often small trees or shrubs but can also be larger perennials or grasses. All have strong stems, branches and seed-heads that retain their shape throughout the season, including into winter. They are often tall and can provide color and texture during the growing season as well.
In this space, I decided to play around with different structural shapes, varying the number and shape and placement. For instance, this version (which I don’t particularly like) has a large shrub on the right, near the brick walkway, several low shrubs in the center, and a clump of grasses in the left corner:
I tried different placements for the large shrub. But because this space is so narrow, the left corner really was the only place for it. Once that was established, a smaller shrub or large perennial would be needed at the other end to balance out the composition, and some smaller shapes, say grasses would be interesting for the center. I tried these as a large clump, but again because of the narrow bed, the composition looked better if they were spaced out a bit more along the length. This also gave more sub-divided pockets for the seasonal interest plants:
Next comes the seasonal interest plants. I find it most pleasing if these plants are grouped into irregular shapes and drifts of 3-5 plants each. This bed is only deep enough to have at most two plant types front-to-back. I definitely wanted plants to the right of the right-most structural plant, to set it back a bit from the walkway. And it would be fun to have plants clustering around the base of the grasses in the middle. Using the Custom Draw tool, I started filling in some shapes:
I don’t know if the homeowner would appreciate this composition, but I kind of like it!
Next, I wanted the criteria for the structural plants and the sizes/heights of the seasonal plants. The big corner plant should definitely be a large shrub that flowers in mid-summer to attract pollinators. The center structural plants would be lovely as taller warm-season grasses that had flowering stems in fall and winter. The right plant could be a shrub, or a larger perennial with stiff stems.
For the seasonal plants, there are 9 clumps, but I think it would look too disconnected if they were all different. At least 2 of them should be repeated. The heights should vary, from low to medium-tall. I added these details to the diagram and adjusted the shapes to show the heights better:
So far, this design process is exactly the same as if we were using traditional garden plants. Now, it’s finally time to explore native plant options.
For the shrub, I turned to the University of Connecticut plant data base. They have compiled a database of woody plants for zone 6 and colder. I searched for a medium (4’-8’) shrub for full sun and average moisture and allowed it to be native anywhere in the US. They returned about 20 shrubs, and by evaluating each plant I could eliminate most as flowering too early, spreading too aggressively, or not having the structural appearance needed.
For the grasses I used the plant finder on the New England Wildflower Society site. And for the tall perennial, I continued with the NEWFS plant finder, and supplemented that list with aa Pollinator Garden list from the University of New Hampshire Extension. For more detail on each plant, I used the Missouri Botanical Garden Plant Finder. I was able to narrow the list down to two plant options for each situation – it’s always good to have a Plan B!
For this exercise, I will choose the smooth hydrangea (after all, what would a Cape Cod garden be without a hydrangea?), the switch grass (because I love the blue color of the grass) and the Joe-Pye weed (because of the long-lasting blooms). But the other choices would work, too.
For the perennials, I searched both the NEWFS site and the University of New Hampshire Extension site for pollinator-friendly plants that meet the site conditions. Again, I narrowed it down to six plants, with a variety of color and shape, all of which are generally available:
Note that for both the structural plants and perennials, there are some straight species and some named cultivars, and this is deliberate. My preference is to stick with the straight species where possible, but to go with a cultivar if needed for size, or if the species is unavailable in the nursery trade. I do try to make sure the cultivar still retains the pollinator attraction of the species.
To complete the design, I went back to the shape diagram and matched up the plants with the shapes. The structural plants fit nicely, but when I tried to fit in the perennials, I ended up with plants of the same color next to each other, and not enough continuity. Since all of these plants are long-bloomers, it was important to tweak the placement a bit. I ended up with a scheme that, to my eye, can be enjoyed all summer.
But as I looked at this again, it seemed awfully busy to me. What if I edited this one more time, trying to get bigger groupings of plants? I liked it better – the eye flows a bit more, rather than so much jumping around:
Guaranteed, I could play with this more and come up with further variations and refinements. But I would be happy to plant this and evaluate the design based on how the in-the-ground plants do over the summer. One thing my education has taught me, that the first design is never the final one!