Monday, March 20th, 2017 at 1:00 pm
Last week I focused on 4 native herbaceous perennials that are great for the conventional landscape. In Part 2, we’re continuing the list with another 4 that are some of my personal favorites.
Penstemon digitalis – Foxglove Beardtongue
I have a special affection for the genus Penstemon. There is an enormous amount of diversity in the genus, much of which is native to the southwestern United States. They can be found in nearly every color including white, red, yellow, orange, blue, violet and deep burgundy-purple. Some species have very finely textured foliage while others are more strap-like or spoon-like. Perhaps the most common and well adapted to our area is Penstemon digitalis. In spring, the plant will produce a basal rosette of spoon shaped leaves followed by large 2-3′ stalks of tubular, white, bee-attracting flowers in May and June (sometimes later). After the blooms are finished, the stalks remain upright with seed pods that will remain through winter for interest if not cut back. Penstemon digitalis spreads readily from seed, but is generally not aggressive, only cultivating space that is not being used. If seeding becomes a problem, remove stems by August, before they begin to dry. Penstemon digitalis is very versatile, tolerating dry to somewhat wet soil and full sun to full shade. Best performance will occur in full sun to part shade with moist, well-drained soil. Some of the best cultivars of Penstemon digitalis include ‘Husker Red’ which turns a deep red in autumn, ‘Dark Towers’ which has dark foliage year round and a pink flower, and ‘Pocahontas’ with lavender flowers and dark foliage.
Asclepias incarnata – Swamp milkweed
Ever since planting this species in the garden, I’ve enjoyed the benefits of seeing pollinators flock to the flowers like flies to honey. My favorite visitor is the intimidating Great Black Wasp, Sphex pensylvanicus. If stinging insects are a concern due to the presence of children, I ask you to first take into consideration it’s size. Swamp milkweed often grows 4 to 5 feet tall and 2 to 3 feet wide. The pink flowers are borne at the top of the plants, far away from little hands, and since the plant is better as an accent in the midborder to background, some trampling and height adjustments will need to happen before children are put at risk. Swamp milkweed has a strongly upright to vase shaped habit with medium textured green to dark green foliage. The blooms typically appear between July and early September and are mildly fragrant. Plant in full sun with well drained to wet soil for best best results. Remove seed pods to prevent reseeding. While the plants will usually turn yellow in fall, you will sometimes get more interesting results. If you like swamp milkweed but need a smaller plant, try the variety ‘Cinderella’ which does not exceed 4 feet in height and has darker flowers.
My Asclepias incarnata turned shades of burgundy, red and yellow this past fall.
Mertensia virginica – Virginia Bluebells
Mertensia virginica is a wonderful spring woodland ephemeral that starts pushing out dusty violet to purple foliage in early April, followed by flowers before the start of May. The pendulous bell shaped flowers transition from pink to blue and occasionally occur as a very pale gray-blue. Plant Mertensia in full to part shade or under shade trees in masses for best results. When the plants are done blooming, they will set seed and die back to the ground. For this reason, it’s best to plant Mertensia with other shade loving perennials like Hosta which will fill the gaps left by Mertensia in late spring through fall.
The unopened flowers on Mertensia are pink to lavender.
Sporobolus heterolepis – Prairie dropseed
This native grass is already well beloved by many designers. The gentle sweeping nature of its leaves, along with its open airy panicles and orange-tan fall color makes it a favorite for adding a touch of grace or softness to a planting. Prairie dropseed typically produces 2-3 foot wide arching clumps and grows to about 3 feet tall, though the inflorescences may grow somewhat taller than that. When planting prairie dropseed, it is best to plant later in spring while the soil is warming as it is a warm season grass. Planting late is not usually a concern due its tolerance to extreme heat and cold, but it would be wise to mulch for late planting dates. The most notable thing about prairie dropseed may be its fragrance, which some say smells like popcorn, others say smells like cilantro or soap. If you like the idea of prairie dropseed but are looking for a slightly improved habit, I recommend ‘Tara’ which is a dwarf version with a more vase shaped habit.
There are many more natives suitable for the landscape and we’ll discuss them further throughout the season. In the meantime, join our conversation on Facebook. We want to hear from you, what are your favorite natives?