Design your garden bed so that all plants are on display. Border beds could have short plants in front, one or two tiers of medium-height shrubs or grasses, and a backdrop of tall, vigorous viburnum, podocarpus, banana, or bamboo.
You’re walking through a nursery, drooling over the plants, trying to make selections for a new bed you’ve cleared out. In your mind, you see the established bed with tiers of lovely shrubs, low plants, and groundcovers. With a backdrop of, say, a dark, leafy hedge or bamboo or banana trees.
As you browse the nursery inventory, you quickly realize that all the plants are young. Immature. Small. It dawns on you that to achieve tiers in a bed, you’d better know the mature height of the plants. And probably, be prepared to do periodic pruning.
Here is our two cents’ worth on how to design your garden bed to end up with a pleasing staircase of mature plants.
First: Identify Your Bed Type
Your garden bed is probably either an island bed or a border bed. The former may be surrounded by turf. The latter usually butts up against a house or a property line or a fence. Island beds are often ovals or organically shaped and can be walked around and seen from all sides. Border beds may have straight or undulating edges and are mostly seen from the front and sides.
Second: Scope Out Other Gardens for Ideas
It can be hard to visualize a full-grown plant when all you see is the three-gallon pot version at the nursery. We suggest taking some time and checking out other people’s gardens. Go for a walk and see what the neighbors are growing. Visit established gardens in your city. Browse Pinterest and other online inspiration sites. Note the plants that you love, search out their names, and find them at the nursery.
Don’t forget print resources. Florida residents will benefit from books such as The Florida Gardener’s Book of Lists (Chaplin and Brandies). It contains lists like “Shrubs for Groundcovers,” “Tall Annuals,” “Tall Ferns,” and “Azaleas by Height” (dwarf, semi-dwarf, and large). Or Florida Gardener’s Guide (MacCubbin and Tasker), which features 200 great Florida plants and gives the height of each one.
Third: Guidelines for Placing Plants
We recommend a back-row planting of a species that does well on autopilot. Give the plants enough space to spread to their natural width and height without requiring much maintenance. Depending on the depth of your bed, install back-row champions such as bamboo, banana trees, podocarpus, viburnum, or philodendrons.
The next level should be medium-height shrubs or grasses which may or may not need pruning to keep them 3-4 feet tall. Florida candidates include jasmine, plumbago, snowbush, loropetalum, thryallis, Ixora, boxwood, red fountain grass, and dwarf azaleas.
Man the first tier with short plants such as impatiens, petunias (in winter), vinca, Blue Daze, Mexican heather, liriope, dwarf Ixora, Ilex Schillings, Dusty Miller, and society garlic.
If you’re filling an island bed, put medium-height plants in the middle and lower ones around those. The only tall plants should be single, or specimen, plants such as small trees or palms.
Last Words: No Plant is Permanent
You can always pull out a plant and replace it with another. Obviously, you’d prefer to get it right the first time, but if, despite your best planning, the established plant heights don’t work well, just start again.