What was James Taylor dreaming about when he wrote “deep greens and blues are the color I choose” in his song “Sweet Baby James?” Maybe it was the variations of the two colors that work so well in a perennial garden.
With so many shades of blue and green to choose from, it’s easy to create a garden in any micro-climate using these cool colors. The choices of varieties are so that a blue garden can thrive in conditions ranging from sun to shade and dry to moist. There are also enough to choose from that layers from one to five feet high can be created, allowing for the inclusion of many varieties in the garden.
Along with size variation, there is also an opportunity to use plants that will provide a succession of color throughout the season. One of the best reasons for using blue perennials in this area is because there are so many that are hardy and thrive rather than just survive, which cuts down on weeds and replacements.
Here’s an approach for perennial choices for a sunny garden, with layering from foreground plantings to the background.
Start with a favorite border of “Walkers Low” Nepeta. It is a durable, fragrant, drought- and deer-tolerant perennial that grows 12” to 18” with blue-green foliage and light blue flowers that bloom in early April and continue throughout the summer.
Along with Nepeta, another great border is the balloon flower, which offers many varieties, grows about 18”, blooms during the summer, and is drought tolerant. It is often overlooked for other choices but has much to offer, such as the changing shape of its flowers and its soothing blue color. As an alternative to, or along with, Nepeta, a cultivar of blue salvia should be considered. “May Night” is one variety that has a long blooming period and re-blooms after it is cut back. It, too, is deer tolerant.
There are plenty to choose from for the interior of the garden. Some favorites to mix in a biomorphic, almost random, pattern could include varieties of iris, such as “Caesar’s Brother,” the slender, deep green foliage of which looks great even when it is not blooming, and other blue iris varieties like “Blue Sky” and “Dangerous Mood.” Amsonia “Blue Ice,” phlox “Blue Paradise,” Caryopteris “Blue Knight,” Russian sage, and blue lobelia should all be included in the blue garden and will keep colors flourishing throughout the summer.
Depending on conditions, the background should always have some baptisia. Use varieties like “Blueberry Sundae” or “Purple Smoke,” which are extremely drought tolerant, grow three to four feet high, and bloom in late spring. For a sunny, dry area, consider sea holly in bunches since it grows up to 36”. It also has a unique silver-blue flower that is often used in dried arrangements.
Aconitum, with its late fall flower that reaches almost five feet, is an added thrill that should be marked for the garden. As for annuals, sneaking a few “Black and Blue” salvia and blue daisies into the mix always loosens up the garden and brings a welcome flower.
The deep, green foliage of “Blue Angel” hosta; varieties of ferns; “Harbour Dwarf’ nandina; and even liriope, balance the garden with their various shades of green foliage. Mazus, wild ginger, dwarf bamboo, and ajuga have both flowers and foliage that should make their way into the garden, as well.
When dreaming of deep greens and blues for the garden, the only rules to follow are layering and choosing a variety of plants that will thrive in in the garden space.