Let’s Go Vertical

by Mark Dwyer

I can still recall my first course in landscape design at the University of Illinois (Champaign-Urbana) over 30 years ago. I was more focused with fussing over which circle template to utilize and which fancy symbols I would use to denote various plantings than really understanding design concepts. Oddly enough, there was a heavy focus on graphics even prior to a rudimentary understanding of plant attributes and contributions. As a novice, my perspective of those sample landscape designs as they were being rendered in a juvenile fashion on vellum was really just two-dimensional. How much room did I have to place that tree or those shrubs? Where was the sidewalk and driveway in relation to the front foundation area? How high were the windows from the ground and what other input was coming from our pretend clients regarding this space? While these are all valid questions, the reality of creating landscapes that incorporate all three dimensions continues to be an aspiring goal as the dynamism and growth of the landscape make these spaces very fluid in their consideration. My two-dimensional rendering should translate to a strong statement of scale, space and certainly ornamentality in the “real world”.

Of course our landscapes exist in three dimensions but we tend to focus most specifically on available ground space. We might consider appropriate plantings that offer beauty, but also will be in scale with their surroundings and adjacent plants. I would argue, however, that we give short shrift to strong vertical elements in the landscape. That’s not to say that we don’t have vertical elements included in our landscapes. These are represented by plants as well as “non-living” features like fences, walls and other structures. However, the purposeful inclusion of strong verticals can provide definition, scale, softening, screening and shelter. In interactions with my clients over many decades, I’ve always explained why I’ve selected and placed these “exclamation points” in the landscape.

When entering any outdoor space, I also tend to notice the vertical elements that help create the setting or perhaps define an “outdoor room”. This might include a row of upright evergreens offering screening and privacy or perhaps the repetition of a gardening structure that adds instant verticality. We don’t just decorate an interior room with a carpet, there is lots of other furniture, curtains, lamps, wall hangings, etc. that soften and scale the room. Plants and garden features that provide verticality, when used prudently, are extremely effective additions that will improve the outdoor space and garden room.

Incorporating more verticals in your landscape shouldn’t be confused with vertical gardening which does have some of the same goals. “Vertical gardening” is a bit ambiguous as a term but really represents a style of gardening that maximizes limited space or relies on a specific planting style (i.e. espalier of a tree along the side of a wall or vines up the trunk of a tree). A limited amount of space would certainly lend itself to the consideration of this style and perhaps the inclusion of vertical elements (like narrow trees) to establish height, define scale and provide structure. Ideally this vertical contribution is lengthy and year-round.

My exhortation to GO VERTICAL! involves the intentional use of “horticultural exclamation points” such as fastigiate or columnar selections of trees as well as other elements like garden obelisks and upright planters. In regards to narrow woody plants, both deciduous and coniferous opportunities abound and I’m a sucker for a narrow plant. Why do we purchase and install “narrow width” woodies in the landscape? Certainly, there is no shortage of pragmatic reasons like avoiding overhead powerlines, space or canopy limitations, intentional formality, functional hedging, etc. In terms of ornamental design however, a well-placed, upright tree can truly be a focal point in any situation and adds some “pop” with a desirable vertical line. The terms “columnar”, “fastigiate” and “upright” tend to be used casually and generally still refer to a narrow selection. More accurately, columnar selections roughly have a 5:1 ratio of (continued on page 12)

(continued from page 11) height to width with fastigiate selections described as a 10:1 ratio (narrower). Upright as a term indicates a certain narrowness but also likely refers to some of the branching pattern. Regardless, accomplish due diligence and make sure you’re installing a desirable-sized specimen that also is well suited for the site (obviously!).

Plant form, whether subtle or more prominent, certainly plays a role in any composition and landscape setting. While my focus in this article is on vertical elements, I also find sit- uations where a weeping, rounded or prostrate form might be a nice accent. The design strength of any vertical is closely related to its positioning in the landscape. One of my favorite local uses of strong vertical trees is at the Chicago Botanic Garden (Glencoe, IL). As you leave the visitor’s center and head across the bridge into the garden, a long row of fastigiate European beeches (Fagus sylvatica ‘Fastigiata’) offers a beautiful formality along the path and helps separate two primary garden spaces. While slow-growing, there are some amazing (continued on page 14)

• Amendment and Mulch in One

• Fuller, Healthier Plants

• Suppresses Weed Growth

• Requires Less Watering

• Includes Mycorrhizae & Gypsum

• Skip the Rototilling (see website for info)

(continued from page 12) selections of upright beeches like ‘Red Obelisk’, ‘Dawyck Purple’ and ‘Dawyck Gold’ that I commonly use for a solitary focal point or an element of repetition that will continue to gain height and scale as time progresses. Very narrow forms of maples, ginkgos and so many more genera are out there although availability may continue to be a challenge.

Perhaps you’ve noticed the amazing amount of breeding and selection work occurring with oaks (Quercus) for extremely tight and narrow forms? Twenty years ago, I was reliant on upright English oak (Quercus robur ‘Fastigiata’) but now that selection has been brought into breeding programs with many of our natives and we’re seeing extremely narrow, hybrid selections that lend themselves to tight locations, building corners and parkways. There are also narrow selections of natives like the Beacon® swamp white oak (Quercus bicolor ‘Bonnie and Mike’). Personally, I’m a huge fan of the Crimson Spire™ hybrid oak (Quercus x bimundorum ‘Crimschmidt’) which has fastigiate English oak and white oak (Q. alba) parentage. This tree does ultimately get about 15’ wide and 50’ tall but maintains some amazing fall color as well. There are many excellent, narrow oaks currently out in the market.

With conifers, there are also many narrow selections commonly available. That has certainly been the case with a plethora of narrow arborvitae (Thuja occidentalis) selections which do have their place in the landscape. Knowing full well what deer can do to arborvitae, common design use includes use as an accent but also hedging or “living fence” establishment for privacy and screening. The durability of arborvitae can’t be disputed but I’m even more excited about the extremely narrow selections that also feature a single leader which allows them to shed snow better than older forms that splay open with heavier snow loads. I use lots of ‘American Pillar’ and North Pole® for these situations. There are very narrow forms of many other conifers as well. If you have a tight spot and a traditional Norway spruce (Picea abies) will get too large, try the narrow variety, ‘Cupressina’, with ascending branches and a symmetrical form. Weeping Alaskan cedar (Callitropsis nootkatensis, formerly Chamaecyparis), has some amazingly narrow (but strictly weeping) forms like ‘Green Arrow’ and ‘Van den Akker’ that are curious and engaging focal points in the landscape. Consider the value of these vertical conifers and their contributions for 365 days of the year!

In my 21 years as Director of Horticulture at Rotary Botanical Gardens (Janesville, WI), I also explored an interesting and colorful approach to including “non-living” verticals throughout 20 acres of display gardens. We utilized obelisks (narrow, wooden, four-sided vining towers), vine pyramids and even painted culvert pipes and PVC pipes to offer instant color and verticality. The obelisks ranged in height from 3’ up to 20’! In many of these instances, there was a limited amount of space (particularly bed depth) that called for this approach. In larger garden areas, these elements would offer a strong, visual anchoring and typically were painted colors (annually) that corresponded with our annual color themes. The obelisks and pyramids frequently supported colorful vines while the pipes and tubes included inserted planters with cascading plants that were beautiful (and admittedly very hard to water!). Fanciful? Perhaps. Effective? Absolutely.

When you’re observing, evaluating, designing or planting any landscape, be sure to consider the incorporation of strong vertical elements. Going vertical will help create a unified, crisp and scaled landscape that becomes a more engaging space to enjoy visually and personally.