How to Select the Right Size Shrub
Shrubs are a key element for building good garden bones so it's important to get their placement right. An out-of-place shrub is a lot like a misaligned nose on a face; it throws the whole picture off.
One way we get the arrangement wrong is by selecting shrubs that are out of scale - either too large or too small. It's a mistake that's easy to avoid when you know the amount of space available, the role the plant will play in your garden's design, and the mature size of the plant.
First look at the dimensions of the space. Can it accommodate the 12 foot tall Chinese snowball viburnum you have your heart set on? Conversely will a dwarf shrub be dwarfed by the surroundings?
Next decide the function of the shrub. Is it for screening, a focal point, foundation planting, or an element in a mixed border? The purpose will help determine the desired size.
Screening – What do you want to hide? Something tall like 'American Pillar' arborvitae (240 – 360 inches) is an excellent choice for blocking the view of the neighbor's garage while medium-sized shrubs like boxwoods will hide an AC unit without making it difficult for repairmen to access. If you want to camouflage a chain link fence without hindering the view beyond try a mix of evergreen and deciduous shrubs that mature to the top of the fence.
Enclosure – You can use shrubs to create living walls for garden rooms. Plant shrubs closely to create a hedge. Choose tall growing bushes such as arborvitae, camellia and holly for secluded rooms or something shorter for the illusion of enclosure.
Focal Point – Every garden needs a statement maker to draw the eye. Shrubs offer blooms, foliage and berries for a seasonal focal point. A large shrub such as Snow Storm™ spiraea (36 – 48 inches tall) will capture attention in spring with massive white fountains of blooms and again with orange and red fall foliage. For a smaller space try planting a grouping of dwarf shrubs like Show Off™ Sugar Baby Forsythia for a solid drift of cheery yellow blooms. For winter interest in a garden with space consider the tree-like deciduous holly Berry Nice® winterberry. The red berries are a knock out and the birds love them.
Foundation Planting – When it comes to foundation plantings, choose shrubs that will accent your home rather than hide it. You can frame a house with tall shrubs at the corners and plant low growers such as White Album™ euonymous across the center. Beware of planting shrubs beneath windows that will grow too tall and block the view. To keep it interesting use a mix of evergreens and deciduous shrubs or, if you choose all evergreens, contrast the leaf shapes and textures.
Mixed Border Companion – Shrubs are a carefree way to jazz up bed of perennials and annuals. Placement in the border will determine what size shrub you need. Plant taller varieties in the back, medium in the middle and low growing in the front. Also consider the size of the border itself so your selection does not overpower its bedfellows. Lo & Behold® Blue Chip butterfly bush is a petite version of the popular butterfly bush that is perfect for getting the blooms "front and center." More stately specimens such as Bloomerang® Purple lilac or Incrediball® hydrangea are suited for the back of the border.
Now that you know what size plant you need it's just a matter of matching the right size with shrubs that will thrive in your climate and growing conditions – sun, water, and soil. Next, select ornamental characteristics that appeal to you and that suit the purpose of the shrub. Evergreen or deciduous? Flowers? Fruits? Fall foliage? Funnel down until you land on the perfect shrub for your space, environment and purpose.
So you see, when it comes to shrubs, size does matter. By determining the right size shrub first, you'll ensure that your choice will enhance the framework of your garden.