Pennisetum setaceum is a tender perennial fountain grass that is native to Africa, southeast Asia and the Middle East. It is a rapid-growing, clump-forming grass that produces arching, linear, narrow green leaves to 3’ tall and late summer flower spikes that rise above the foliage to 4’ tall. In warm areas where in may be grown as a perennial, it readily self seeds. In colder areas it dies in winter. Location means everything. Overall clump appearance is reminiscent of water spraying from a fountain, hence the common name.
Genus name comes from the Latin penna meaning “feather” and seta meaning “bristle” in reference to the flowers having long, feathery bristles.
‘Rubrum’, sometimes commonly called purple or red fountain grass, is a burgundy-red leaved cultivar that is not invasive under any circumstances because, unlike the species, it rarely sets seed. Showy, fluffy, burgundy-purple flowers in bottlebrush-like spikes (to 12” long) top flower stalks that arch upward and outward above the burgundy-red foliage clump in summer.
Specimen, group or mass. Attractive foliage and flower spikes of this ornamental grass provide excellent texture, color and contrast to borders, foundations and open areas.
Winter hardy to USDA Zones 9-10 where it is easily grown as a perennial in average, medium moisture, well-drained soils in full sun to part shade. Best performance is in full sun. In St. Louis, it will not survive winter and is typically grown as if it were an annual. Although species plants can be grown from seed each year new plants are typically purchased from nurseries each spring for planting in the garden after last spring frost date. Technically plants can be dug in fall, trimmed and overwintered in greenhouses or indoors in sunny cool areas, but many gardeners simply prefer to purchase new plants each spring. Plants may need some staking or other support and should be sited in areas protected from strong winds. Provide consistent water throughout the growing season.
Calamint, Lesser Calamint
Photo credit: Stonehouse Nursery
Like a cloud of confetti, tiny white flowers (sometimes touched with pale blue) appear from early summer to fall. Undemanding and dependable, calamint provides the perfect foil for other summer bloomers and foliage. This full-sun perennial has a low mounding or bushy habit, ideal for the front of the border, rock gardens, and more.
While durable and pest-free, calamint also checks two important boxes for gardeners: bees and other pollinators work the flowers throughout the summer and the aromatic foliage is deer-resistant.
Calamintha nepeta subsp. nepeta is a favorite low-growing component in stylized meadows, matrix plantings, and other modern perennial designs. Gardeners can also create a lovely monochromatic garden with more sure-thing perennials including past PPOYs such as Anemone xhybrida ‘Honorine Jobert’ and Phlox paniculata ‘David’, or complemented with ornamental grasses such as Panicum virgatum ‘Northwind’ (switchgrass) or Schyzacharium scoparium (little bluestem).
Photo credit: Midwest Groundcovers
Hardiness: USDA Zones 5 to 7
Light: Full sun
Size: Up to 18 inches tall and wide
Native Range: Great Britain to Southern Europe (Griffiths, M. 1994. Index of Garden Plants, Timber Press: Portland, OR)
Soil: Best with good drainage – tolerates some drought once established.
Maintenance: Low-maintenance deciduous perennial. Can shear back lightly if desired to create neater habit or refresh spent blooming stems. Tolerates drought once established.
Nomenclature: What’s with the “subspecies”? Abbreviated subsp. or spp., this is a naturally-occuring, phenotypic variation to a species that is usually related to a geographic situation. This subspecies was selected for size and vigor. May also be found under the following synonyms: Calamintha nepatoides and Clinopodium nepeta.
Grower Notes: Calamintha nepeta subps. nepeta has no patents or other restrictions. Propagate by vegetative cuttings (stem or root). Vernalization not required. Spring planting yields a one-gallon in 8-10 weeks. Grow on the dry side. Smaller pot sizes not recommended. Pinch or shear if needed to shape; responds to plant growth regulators.
Because of the abundance of perennials that bloom this month, June has been designated as Perennial Gardening Month by the Perennial Plant Association.
Perennial gardens often bring to mind the classic cottage garden or vibrant perennial border, and rightfully so. Cottage gardens and perennial borders burst with a variety of colors, heights, and textures. Beautiful and evolving throughout the entire growing season, even in the depths of winter, perennial gardens are visually captivating and provide wildlife habitat.
Simply defined, the paradox of choice is being overwhelmed by too many choices. Have you experienced the paradox of choice when trying to decide which perennials to add to your garden?
With virtually endless options of perennials available, creating an entirely new perennial garden or even just adding a few perennials to your garden can be daunting. However, applying these three simple decision-making strategies will help simplify the process and should help make your best options obvious:
Where, What and How?
Is the garden located in full sun or partial sun?
If it is in partial sun; is it morning sun or afternoon sun?
Yes, it does matter. Temperatures of morning sun tends to be cooler than afternoon sun and different plants have difference heat tolerances.
Perhaps the garden is in a shady area. If so, is it in full shade, mostly shade or part shade?
Container garden or in-ground garden
A growing gardening trend (pun intended), is to create perennial container gardens and then transplant the perennials to an in-ground garden bed towards the end of the growing season. Some perennials adapt to transplanting better than others and it is important to know what time of year is best for the plant re-location project.
In general, established perennials will overwinter better when planted in the ground than in a container. However, when overwintering perennials in a container, a general rule of (green) thumb is to subtract at least one hardiness zones. For example, if you live in Zone 5, the perennials should be Zone 4 or lower. To verify the Hardiness Zone where you live check out the USDA Plant Hardiness Zone Map.
Below are a few additional tips to overwintering perennials in a container:
A large container has more mass and holds more soil. This mass provides insulation that helps moderate the soil temperature, protecting the plant’s roots from temperature extremes. The additional soil also helps retain soil moisture.
Cover the soil with organic mulch: bark mulch or leaves, or even a few layers of newspaper. In addition to moderating soil temperature fluctuations and retaining moisture, the cover helps prevent weed seeds from taking up residence in your perennial container garden.
Further protect your perennial container garden by moving it to a more protected area. Even a non-heated garage will help protect it from severe temperature extremes. Since the plants are dormant, light isn’t required, but check the container every few weeks to make sure the soil is still moist. However, be careful not to over-water as this could cause the plant to come out of dormancy prematurely.
Usually perennials are celebrated for their flowers and long blooming period, yet some are infamous for their foliage; think of Hosta, succulents, and ornamental grasses. An ever-growing (another pun?) category of perennials are those with unique foliage such as Heuchera or Ligularia, that also have notable flowers.
Consider the placement in the garden, whether it be a perennial border or container garden.
o Traditional perennial borders are essentially designed in three distinct sections: the tallest plants are placed towards the back then the mid-height plants and lastly, at the front of the border is most often a low growing flowering perennial or ground-cover.
o A perennial container garden that will be viewed from all angles, or nearly all angles, should have the tallest plant in the center, with mid-height plants surrounding the tallest plant and ultimately the shortest plants around the edge of the container. Just remember the standard container gardening design tenet Thriller, Fillers and Spillers applies in a perennial container garden just as it does for an annual container garden.
For more design ideas and garden maintenance tips read The Blogpost Pile: Coloring Your Garden with Annuals, as the ideas and tips shared in this article apply to perennials as well as annuals.
How much maintenance?
Some perennials require more maintenance to keep them blooming and healthy than others do. Understanding how much time you want to enjoy in the garden tending to your flowers, will help ensure your perennial garden thrives for years to come.
How much moisture?
Determining how much natural moisture your garden receives and how much supplemental water you plan to provide will significantly assist your decision-making process and reduce the Paradox of Choice predicament.
Celebrate Perennial Gardening Month by discovering new perennials or rediscovering your favorite classic perennials at your local garden center.