When I realized that my post Skinny Conifers for Tight Spaces has been read over 40,000 times, it inspired me to create a free booklet for my newsletter subscribers; Top 10 Skinny Trees for Tight Spaces, which expanded that selection to include deciduous and flowering trees as well as conifers. That too has been well received, so here is the next installment: Skinny Shrubs for Tight Spaces.
There are times when you need a vertical element to break up a river of mounding shapes. Or to stand sentry at an entrance point. Or to create a living dividing wall between garden areas. Perhaps you have a narrow side garden and need screening from the neighbors' yet do not want to erect a fence? Or you are just looking for a centerpiece for a container that doesn't get too wide. Basically skinny shrubs are useful where you only have a small footprint to work with yet need some height.
The selection here is far from all-inclusive, but includes many I have used in designs over the years as well as a few newer ones that I'm still testing but look promising. For my garden they also have to be drought tolerant and deer resistant! Here are my current favorite skinny shrubs:
Fine Line buckthorn
I've used Fine Line buckthorn (Rhamnus frangula 'Fine Line') in containers, to create a deciduous hedge, and also to establish a living wall adjacent to a pathway.
This versatile shrub retains is columnar shape without pruning, is deer resistant, drought tolerant, will grow in part shade or full sun and is sterile – so none of the invasive concerns of older varieties of buckthorn. The finely textured green leaves turn bright yellow in fall and the brown woody stems are speckled with white spots, so even after the leaves have fallen there is a sculptural quality and beauty to this shrub.
Ultimate height is given as 5-7 feet tall and 2-3 feet wide but mine have yet to get that big. Hardy in USDA zones 2-7. (There's another really cool combo featuring this in our book Gardening with Foliage First)
Not for everyone, as barberries (Berberis) are invasive in some states, but where these can be grown, consider Sunjoy Gold Pillar (gold) and Helmond's Pillar (burgundy). I've used these in the impossibly small planting beds in front of garages, in containers, to mark the entrance to a woodland path, to create a living fence between neighbors, and as exclamation points in the landscape. They can be planted singly or in groups to great effect. Fall color and berries add to the display.
Incidentally I have seen Helmond's Pillar 6 feet tall and 2 feet wide so the size cited here is rather conservative. Conversely, I have found the golden form to be smaller and slower growing.
You'll find more design ideas using both of these in my latest book Gardening with Foliage First.
Drought tolerant but needs moisture retentive soil to avoid defoliation during extreme summer heat, and has proven to be deer resistant (YAY!)
Barberries are hardy in zones 4-8.
Moonlight Magic crapemyrtle
Crape myrtles (Lagerstroemia cvs.) and Washington state – especially colder regions of the state – are not usually considered compatible as it rarely gets warm enough for the shrubs to bloom. That becomes irrelevant when you have a variety such as Moonlight Magic, with dark chocolate colored foliage in a much narrower form than the better known Californian street trees.
Moonlight Magic grows just 4-6 feet wide yet still gets 8-12 feet tall, so more slender and well-toned rather than truly skinny – but worth your consideration for sure.
I've had success with this in a container for several years now. In landscape designs I could see using Moonlight Magic as a focal point within a vignette or where I might otherwise reach for a purple smoke bush but don't have the space.
Purple Pillar hibiscus
Hibiscus are those shrubs with tropical-looking flowers that are so eye catching in late summer, yet many are too large for the average garden. Purple Pillar is the answer at just 2-3 feet wide. If you plant them 2 feet apart they quickly form a dense summer screen as shown in the photo above.
Don't let lack of a garden spoil the fun. Purple Pillar will grow happily in large containers. These can be placed together to create a privacy screen from the neighbors or hide ugly utilities. White Pillar has similar attributes but with white flowers
There are also several broadleaf evergreen shrubs that are tightly columnar that you might consider, including
Sky Pencil Japanese holly (Ilex crenata 'Sky Pencil')
Columnar Japanese holly (Ilex crenata 'Mariesii') which is more sculptural than Sky Pencil but can be harder to find.
Green Spire euonymus (Euonymus japonica 'Green Spire') – slightly slower growing and not quite so tight at Sky Pencil
Graham Blandy boxwood (Buxus sempervirens 'Graham Blandy')
Summer Ruffle hibiscus (Hibiscus syriacus 'Summer Ruffle') – variegated foliage with semi-double blooms