Landscape Design Principles

Yes, this one’s a “law,” not just a rule! It addresses the root meaning ofgarden, which is “enclosure.” This, to me, is absolutely critical in creating asense of refuge and of feeling oneself within nature’s embrace. The law ofsignificant enclosure says that we feel enclosed when thevertical edge ofa space is at least one-third the length of the horizontal spacewe’reinhabiting. Probably derived from behavioral psychology studies, this rulecame to me from a professor in graduate school, and it was one of the bestthings I learned.
Just yesterday, as I was starting the design of a patio that I wanted toseparate from an adjacent play area, it gave me instant guidance for howtall a hedge I would need: the area was 17 feet wide, and so my hedgeshould be at least 6 feet. Sit near a tree in the park, or a wall, and graduallyedge away, and you’ll see how it works. Of course, there are times when thepoint of a landscape design is a monumental sense of scale or view, but thebest gardens, whatever their size,modulate a feeling of enclosure andopenness, and this rule will help
My formal architectural education also introduced me to the concept of the“regulating line.” The idea is that an element of architecture (for example, adoorway, or a building edge, even a window mullion) or a distinctivelandscape feature (prominent tree, existing pool, property boundary) can“generate”an imaginary line that helps connect and organize thedesign. For example, in laying out one backyard, I projected the lines of itsbuilding addition into the garden space and then aligned the swimming pooland wooden walkway with those lines. The result is orderly and cohesive,even after being softened with planting. “A regulating line,” wrote the greatarchitect (and theoretician) Le Corbusier, “is an assurance againstcapriciousness...It confers on the work the quality of rhythm...The choice ofa regulating line fixes the fundamental geometry of the work....”
Le Corbusier hits on the two aspects (a bit paradoxical, perhaps) that makethe regulating line so valuable. First is the idea of underlying order: that thegarden, for all its naturalness, or wildness, is founded on strong principles—what’s sometimes known in garden circles as “good bones.” Second, thatregulating lines—at least as I employ them—are subjective; it’s the designerwho identifies and manipulates them to create the garden. And I’d say that the use of the regulating line, more than any other concept, separatesprofessional from amateur design.
Certain rules help us refine design. One is the Golden Ratio which is aratio of proportion that’s been observed in everything from the GreatPyramids at Giza to the Greek Parthenon and has been used throughouthistory as a guide to a pleasing sense of balance and order. The practicalapplication that I make of the Golden Ratio involves its sibling, the GoldenRectangle, in which the ratio of the short side to the long side is equal tothe ratio of the long side to the sum of both sides (a/b = b/a+b)—youprobably didn’t know that landscape architects had to learn math.Numerically, the Golden Rectangle ratio is close to 1: 1.6,a proportion Iregularly use to lay out terraces, patios, arbors, and lawns.Theraised bedsin my vegetable garden are 5 by 8 feet. It’s a rectangularproportion that always looks good—they don’t call it golden for nothing!
Another ratio may even be platinum: That’s what I’ve always called the rulefor step design advocated by landscape architect Thomas D. Church, oftencredited with creating theCalifornia style. Laid out in his seminalworkGardens Are for People, it says simply thattwice the height of theriser plus the tread should equal 26 inches. That means that if the riseris 5 inches, the tread (what you walk on) should be 16 inches. All I can sayis that the rule is true, and I’ve used it from steep canyon faces to gentlechanges of patio levels. A useful corollary states that 5 feet is the minimumwidth for two people climbing steps side by side.
A final rule related to scale and the sculpting of space is this:Go big.Facedwith a decision to make a staircase wider or narrower, a pool longer orshorter, a pergola higher or lower, the answer is almost always the former.In my own garden, I remember laying out an arbor, with its posts 10 feethigh, and listening to trusted friends wondering whether it wasn’t “a littletoo tall.” Thankfully I stuck to my guns, and some 18 years later, wreathedin wisteria and anchored at the ground by clusters of pots, the arbor seemsjust right.
It’s with plants, probably more than any other element of gardens, that theinfinite variation and fickleness of nature is most evident—and so perhaps, they are the trickiest to prescribe rules for. And yet, successful planting isthe crowning touch of a garden. Three rules have always served me well.First, is to plant big to small:start with trees, then shrubs,thenperennials, then ground cover. This is important not only in acompositional way (seeing the bigger forms first gives a better sense of theoverall structure), but in a completely practical sense. Setting a big treemay require machinery or at least multiple gardeners and ample space formaneuvering and stationing amendments and soils; it would be sad todamage or undo some newly planted bed. This seems so obvious, but forlots of gardeners (the author included) a block of fresh perennials may beimpossible to avoid planting right away. Be strong; resist the temptation.
While there is much to be said for thecottage garden, with a rich array ofvaried planting (indeed, it’s the real master gardener who can pull thisoff),there is a power to seeing a quantity of one plantthat isgenuinely affecting. Russell Page, one of the great twentieth-centurylandscape designers said it well: “the most striking and satisfying visualpleasure comes from the repetition or the massing of one simple element.Imagine the Parthenon with each column a different kind of marble!”I remember as a beginning garden designer in California being taken asideby my mentor, a transplanted Englishwoman who owned the nursery,walking through a vast block of salvia, and being told that I could, if Iliked, use 30 of them—not the three or five I’d typically been planting. Itwas a liberating moment.
Maybe my favorite rule of all time, all the more charming for its need to beadjusted for inflation:It’s better to plant a 50-cent plant in a $5 hole,than a $5 plant in a 50-cent hole. Imparted by Ralph Snodsmith, my firstofficial gardening teacher at the New York Botanical Garden and talk radiohost (a character whose working uniform was always a forest green three-piece suit), there is no greater planting wisdom. No matter how brilliant aplan one conceives, if the plants are not well planted—at the right height, ina sufficiently sized, and properly amended pit—the results will likely bepoor. Some rules just can’t be broken.

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