Phlox paniculata ‘Jeana’

As the summer wears on it can be difficult to maintain color in your garden, so it’s good to keep some plants in your garden that show off their flowers later in the season. P. paniculata ‘Jeana’ can be found all over campus, but it is particularly striking in the Dean Bond Rose Garden.

As the lavenders and sages finish their active flowering, this garden phlox rises up four to six feet, making sure that you can see its lavender flowers. Garden phlox is native to eastern North America and was one of the first plants transported back to England during the colonial period. It was highly valued for its bright flowers, and the leaves were often used for making teas.

‘Jeana’ is particularly resistant to powdery mildew, unlike many other Phlox cultivars. It was named after the woman who discovered it, Jeana Prewitt, in Nashville Tennessee. When planting this phlox make sure to give it full sun. This plant gets tall and the flower panicles can be very dense so consider setting phlox in the back of a garden bed to avoid covering up or blocking other plants.

If you want to give this gardening gem a try, Phlox paniculata ‘Jeana’ will be available for purchase at the Scott Arboretum Selections: Fall Sale on September 15 to 17. photo credit: G. Wermeling

Pennisetum Vertigo ® Purple Fountain Grass

Grasses are not typically the first choice for ornamental/pleasure gardens. One might instead think of the turf grass on their lawn, or an ever encroaching stand of bamboo the neighbor has.

Pennisetum, or fountain grasses, can grow upwards of 5 feet tall, and display fantastic colors. Species of fountain grass are found all over the world, including the cereal grain, millet. The Terry Shane Teaching Garden has several of these grasses.

Vertigo ® was cultivated specifically for its deep purple foliage. This combined with its height results in quite a dousing of color for your garden. The leaf color is not seasonal, so as long as individual is healthy the leaves will retain their purple color.

Vertigo ® is an annual in this area, zone 7. It cannot survive temperatures below 15 degrees. Dead foliage can be removed in early winter or left till early spring. The dead foliage will retain its shape during snowfalls and looks quite fetching when covered with snow.  photo credit: G. Wermeling

Achillea ‘Strawberry Seduction’

Achillea ‘Strawberry Seduction’ is being grown in the Cut Flower Garden behind the Wister Center. As its name implies, ‘Strawberry Seduction has a vibrant red flower color. It is also very compacted, never growing more than two feet tall. It likes full sun and very well drained soil.

Achillea, yarrow, responds well to bi-yearly division, although in a suitable environment it can become invasive. Yarrow is well regarded in butterfly gardens for attracting healthy insects and pollinators, while repulsing pests, deer, and rabbits. photo credit: R. Robert

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Geranium Rozanne® ‘Gerwat’

Large swaths of this hardy geranium cultivar, also called cranesbill, can be found around the Harry Wood Courtyard Garden. Geranium Rozanne®  was bred for its clumping growth habit and almost non-stop flowering during the summer. It forms mounds up to two feet wide.

Its large, violet-blue flowers can be deadheaded as they fade to increase further blooming. Rozanne® has excellent heat tolerance thriving in full sun and part shade. As long as your soil is not waterlogged, this cultivar should be happy. Photo credit: R. Robert

Chamaecyparis obtusa ‘Nana Gracilis’

Chamaecyparis, or falsecypress just might be my favorite genus of plant, and there are quite a few on campus. While I was in the Harry Wood Courtyard Garden, I stopped to appreciate the dwarf cultivar ‘Nana Gracilis’. Known as the Hinoki falsecypress, C. obtusa is highly valued in its endemic country of Japan, for the quality of its wood. The aromatic wood is also used to make incense, although the pollen of the Hinoki falsecypress is one of the biggest contributors to hay fever in Japan.

‘Nana Gracilis’ combines the attributes of two cultivars. ‘Nana’ was bred as a compact cultivar, while ‘Gracilis’ was bred for its slender, ornamental growth habit. ‘Nana Gracilis’ is a compact variety, although some individuals in England have reached eleven feet in height. An average mature specimen will be six to nine feet in height with a very distinct pyramidal growth habit.

The dark green foliage is compacted, giving the plant a rich texture. ‘Nana Gracilis’ likes moist soils with protection from strong winds. As a compact variety, ‘Nana Gracilis’ is often trained as bonsai. Photo credit: G. Wermeling

Piper auritum

You can get a good whiff of Piper auritum near pergola in the Terry Shane Teaching Garden. Known as the root beer plant, the aroma can be easily rubbed onto the fingers from the leaves.

While this plant has historically been used as an herb, you may be surprised one day to find yours approaching six feet tall. P. auritum has a shrubby growth habit but cannot survive temperatures below 32 degrees.

It can be raised in a container, provided you bring it inside during the winter. P. auritum does best in full sun to partial shade. Be careful to not allow the plant to dry out Kids and adults alike will enjoy smelling the root beer plant in your garden. Photo credit: G. Wermeling

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Digitalis ferruginea

As I walk around the Scott Arboretum in the summer I am always drawn to big hubs of pollination.  The rusty foxglove patch in the Scott Entrance Garden is one of these hubs.

Both the common and latin names stem from the particularly rusty color of the flowers of ferruginea.  D. ferruginea puts up tall spikes of flowers about the beginning of June and they are visited heavily by honey bees.  They also attract hummingbirds.  The flower spikes make good additions to cut flower arrangements.

D. ferruginea naturally grows as a biennial, overwintering its first year with a single basal rosette of evergreen leaves. However, foxglove is such a good self-seeder that once you plant it, your garden will have it for many years. Another strategy for foxglove is to train it as a perennial by cutting back the flower spike before it goes to seed in early autumn.

D. ferruginea likes partial shade and very moist soil, and is fairly tolerant of disease and pests. Rusty foxglove looks very at home in a naturalized garden setting. Alternatively, the tall flower spikes can add contrast to tall sculptures and walls.  Photo credit: G. Wermeling

Lavandula x intermedia ‘Phenomenal’

Continuing my walk I head to the Dean Bond Rose Garden to look for pollinator systems and I am not disappointed.  The lavender is in full bloom and is absolutely covered with honey bees.

The plant gives off a strong, identifying fragrance.  Its tall spikes of flowers could easily be combined with rusty foxglove flowers in arrangements.  The plant is often used by growers to make oils.  Beekeepers often grow lavender to support their farms.  Lavender plants have been prized by humans for thousands of years; the bible mentions lavender by its ancient greek name, nard.

Most accounts of this cultivar of lavender are so enthusiastic that the name ‘Phenomenal’ seems completely appropriate.  It is deer, drought, and heat resistant; it needs full sun. There is almost no winter die-back, and the foliage remains year round.

The lavender plants in the rose garden have large, very even spreads radiating from a center.  ‘Phenomenal’ can also be grown in containers to lend fragrance to a deck or patio.  Photo credit: G. Wermeling

Nepenthes sp.

On my way back to the Wister Center, I noticed a slightly more one-sided plant-insect relationship hanging from the trellis in the Terry Shane Teaching Garden.  It is a container of Nepenthes sp., also known as pitcher plants or monkey cups.  These plants are carnivorous and use their pitchers to trap and digest any insect which slip in.  The pitchers grow from extended leaf midribs, called tendrils.

Nepenthes species are generally very difficult to classify in the field because most mature species exhibit leaf dimorphism based on height.  The pitchers at the base of the plant are larger and the pitchers at the top are smaller with tendrils more adapted for climbing.  If kept in a basket like those at the Scott Arboretum the plants only grow their larger, lower pitchers.

Nepenthes are largely endemic to eastern hemisphere tropical montane regions such as Southern China, Malaysia, and the Philippines.  They garnered the name monkey cups because monkeys are routinely seen drinking out of the cups.

Due to their mountainous growth habit Nepenthes tend to be happy with temperature ranges from 60-90 degrees.  They are definitely summer plants and you will want to move them inside come winter.

Many pitcher plants have lids which remain upright, allowing the pitcher to fill with rainwater as the season progresses.  While this does not adversely affect the plant in any way, you should be wary of mosquitoes, as they may lay their eggs in the still water of the pitchers.

Photo credit: G. Wermeling

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Punica granatum

As you walk along the inner courtyard of Worth Hall you will notice a tall shrub with plentiful bright red flowers: Pomegranate.  Scott has four of these ornamental shrubs spread about campus.  They will not begin fruiting until the beginning of the fall semester but their flower show is not to be missed.

Punica granatum is endemic to the region of modern-day Iran, so it is drought-resistant and prefers dry soils.  In wet soil, fungal infections will cause root decay.  Pomegranates can withstand frosts to around 10 degrees Fahrenheit, so be wary of any cold fronts that come through.  As pomegranates mature, they develop a unique, sculpture-like branching habit, adding to their effect as a flashy eye-catcher.  Do not count on replacing one anytime soon; pomegranates can live for over 200 years.

Punica granatum can be propagated very well from seed, although most breeders will use rooted cuttings so that there is no variation in the fruiting habit of the new shrub. The ease with which cuttings can be grown, coupled with its ornamental growth and long life has made the pomegranate a common choice for bonsai.  Photo credit: R. Robert

Mahonia japonica

As you pull into the the visitor parking for the Scott Arboretum look to your left. There you will find a Mahonia japonica nestled into a Carex bed.  There are Mahonias all over campus, each displaying the characteristic features which inspired the common name, holly-grape.

            Mahonia japonica is an evergreen shrub with long pinnate leaves.  Each leaf has six to eight pairs of opposite, holly-shaped leaflets.  The leaflets are as sharp as holly leaves, and can hurt when brushed against.  Give M. japonica plenty of space when you plant it.

Holly-grape shrubs provide year round entertainment between their foliage and fruiting habits.  They develop inflorescences of small yellow flowers in autumn and keep them through winter and into spring.  These bee pollinated flowers give way to fantastic blue droops of berries in late spring which contrast brilliantly against their reddish stems. Photo credit: R. Robert

Acer palmatum ‘Waterfall’

Two Acer palmatum ‘Waterfall’ stand guard outside the McCabe Library.  These Japanese maples attract attention because they do not have the usual reddish foliage.  The leaves of ‘Waterfall’ are a bright fluorescent green. Come autumn, all of the foliage will turn vibrant shades of orange.   The tree displays a beautiful weeping habit and never gets much taller than eight feet.  It likes partial shade, making it a nice tree to plant under the more commanding trees in your garden, or along the side of your house.

Like other low-growing weeping plants, Acer palmatum ‘Waterfall’ requires a close eye and occasional pruning to avoid its encroaching on other features.  Maintaining a good watering schedule is especially important for a newly planted tree. Photo credit: R. Robert

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With last week’s commencement, the tradition continued of graduating seniors each receiving a rose from the Dean Bond Rose Garden.  Roses can be notoriously difficult to grow, and are plagued by many diseases and pests.  Scott Arboretum grows hardy cultivars like ‘Lord Penzance’ which are less affected by these problems and easier to manage.  ‘Lord Penzance’ is a climbing shrub found around the perimeter of the rose garden.  The flowers are pale pink to yellow with five petals.  The foliage has a strong, sweet scent, making it a great accent along the border of a bed.  Photo credits: G. Wermeling

Syringa x presoniae ‘Nellie Bean’

While on the subject of good smells consider the ‘Nellie Bean’ lilac.  Full-sized this can be a rather large shrub producing big panicles of sweet smelling lavender to rosy-pink flowers.  Expect plenty of bees when this lilac blooms in May.  This is a shrub that you want in a prominent place when it is at its prime.  While you will find these shrubs on campus in the shadow of Pearson Hall’s east side, this cultivar is very heat tolerant so don’t be afraid of giving it more sunlight.  Photo credits: G. Wermeling

Cladrastis kentuckea ‘Sweetshade’

Walking in the John W. Nason Garden you cannot avoid seeing all the flowers of Cladastris kentuckea ‘Sweetshade’.  If you are planting this tree you have to know that you will find these flowers all over your garden, giving the impression that there was a recent snow flurry.  These beautiful white blooms drift to the ground throughout the day while C. kentuckea is in bloom.  These trees, commonly known as yellowwood, are fairly hardy, requiring little maintenance generally, although a strong, late frost could damage the blooms.

‘Sweetshade’ is a medium sized tree that likes full to partial sun.  It provides good shade and has deep roots so you can grow many shade-tolerant plants underneath; try growing plants you think would look good accented with the white flowers of C. kentuckea when they fall.  Photo credits: G. Wermeling

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