Syringa vulgaris ‘President Lincoln’ (common lilac)

Early fall, the leaves are changing, the colchicum are blooming, and the Lilac Collection is scented with the heavenly smell of those lovely purple flowers. Wait, no, can that be right? But yes! A stroll through the Lilac Collection will reveal a variety of our specimens in bloom including the Syringa vulgaris ‘President Lincoln’. 

But how can this be? Stressful environmental conditions during the growing season such as heat, drought, severe defoliation from disease or pest, and/or heavy pruning can prompt some spring-blooming plants to flower. Lilacs “set” their flower buds for the following year in early summer shortly after the previous spring blooms fade. The stressful conditions we experienced this past summer – heat and drought – caused the plants to go dormant and when the cooler fall weather arrived it tricked them into a false sense of spring, causing the blooms. This untimely bloom will not harm the plant, but since they have used up their spring flower reserves now, there will be fewer flowers on the plants next spring. 

This out-of-season occurrence in some ways is a lovely surprise and in others is a testament to our changing climate and its effects on our much loved plants. Once fall blooms are observed, there is nothing that can be done to fix the issue, however preventative measures can be taken. Good care during stressful conditions, such as extra watering, reducing pruning, and even relocating smaller specimens to more shaded areas can help keep the blooming cycle regular. 

In the meantime, the blooms are here and should be enjoyed. Syringa vulgaris ‘President Lincoln’ is known to be one of the bluest lilacs with its panicles adorning the ends of its relatively loose branches. It can grow to be 8-10 feet tall and wide and is located at the top of the Lilac Collection, nearest to the Friends Meetinghouse. Photo credit: M. Rossman

Cunninghamia lanceolata blue form (Chinafir)

On the edge of the tennis courts in the Pinetum is a lovely needled evergreen also giving clues to the harshness of this past summer. Cunninghamia lanceolata blue form is a beautiful specimen in the cyprus (Cupressaceae) family. It can grow up to 30-70 feet tall in cultivation, but is known to grow up to 150 feet in its native forests of China and Taiwan. A highly valued tree, it accounts for 20-30% of the total commercial timber production in China, while also being used in the medicine and perfume industries. 

It has sharply-pointed, finely-toothed, green to blue-green needles that are spirally arranged on its branches. However, when looking at the Scott Arboretum specimen one will notice that many of its branches and needles are bronze. It is normal for the Chinafir to lose some of its foliage as winter approaches, and has a tendency to hold onto many of its dead needles. And while the contrast of the bronze against blue is striking, it is yet another reminder that all living things felt the harshness of the past summer. Photo credit: M. Rossman

Magnolia ‘March Til Frost’ (Kehr hybrid magnolia)

Pink may be creeping into my list of favorite flower colors, and one specimen that produces a lovely pink is the Magnolia ‘March Til Frost’, located near Old Tarble. This shorter specimen is true to its name and starts blooming with a massive flowering in March or April and will continue to produce sporadic dark- to pale-pink flowers all summer and early autumn until the first frost. And while it does still have a couple of blossoms waiting to open, what really caught my attention was its lovely cones, which are an attractive magenta. These upright seed cones are beautifully contrasted with its dark green foliage. Since this specimen is on the shorter side, the cones and flowers are at perfect eye-level and can be appreciated up close. My fingers are crossed wishing for the delay of winter just so I can continue to admire this magnolia till frost. Photo credit: M. Rossman

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Poncirus trifoliata ‘Flying Dragon’ (hardy orange)

In the stillness of the Theresa Lang Garden of  Fragrance lies a beast of a plant. Clad with large, downward curved spikes, sour fruit, and aggressive seeds, the Poncirus trifoliata ‘Flying Dragon’ certainly lives up to its mythical cultivar name. There is a certain beauty in its frightening nature however. When the sun dares to creep up behind this formidable shrub, its sour fruits appear to glow, the fuzzy coating creating a halo around the 3.5-5 inch fruit. The crooked curving nature of this hardy orange is elegant, graceful, and inviting, but remember – look, don’t touch.  

The Poncirus trifoliata ‘Flying Dragon’ was introduced to the United States from Japan in 1915 and has since then made a name for itself by being invasive in many states. The edible-when-cooked fruits are aggressive seeders, and this plant is known for taking over understories. However, in the Scott Arboretum we are vigilant with removing the fruits before they fall to the ground. 

One of the most cold-hardy cultivars of orange trees, these specimens bloom in the spring with citrus-scented flowers, producing green fruits that transition to yellow that can last well into winter.  I cannot in good conscience recommend this tree for the home gardener due to its invasive nature, however it truly is a living piece of sculpture and I invite you to admire this specimen to get a glimpse of this foreboding beauty. Photo credit: M. Rossman

Anemone x hybrida ‘Honorine Jobert’ (Japanese anemone)

First the Lycoris squamigera (surprise lily), then the Colchicum (fall crocus), and now the Anemone! Magill Walk is certainly showing up for the late-summer, early-fall interest! The current star of the iconic Swarthmore walk is the Anemone x hybrida ‘Honorine Jobert’.

Single blooms carefully carried atop wiry stems, rise above attractive mounds of dark green foliage. These flowers have a breezy disposition, adding lightness and airness to the early-fall garden. This herbaceous perennial blooms from August to October and delights viewers with its pure white flowers and contrasting yellow stamens.

Growing in Zones 4-8, the Japanese anemone is versatile in its growing conditions but prefers dappled shade and evenly moist, well-drained soils. Reaching 3-4 feet tall, the Anemone x hybrida ‘Honorine Jobert’ adds great height to a garden bed without obstructing the view of other plants or surrounding areas. Due to their branching nature, the flowers are able to integrate themselves throughout nearby plants without being pushy. I encourage you to take a stroll down, or up, Magill Walk to see this lovely garden favorite. Photo credit: M. Rossman

Tricyrtis hirta ‘Variegata’ (toad lily)

What plant enjoys shade and has interesting foliage? Does this plant also have neat early-fall flowers? Is this plant loved by pollinators? I’m not sure what plant you were thinking of, but what comes to my mind is the Tricyrtis hirta ‘Variegata’ or toad lily. 

A day has not gone by when I haven’t sought out the grouping of toad lilies in the Scott Entrance Garden to get a close up view of their orchid-like blooms or to watch the busy bees doting on each flower. It’s a joy to watch the bees land on one of their six showy petals and burrow under their crown-like stamen cluster to access the pouch-like nectaries. 

Growing in Zones 4-8 the Tricyrtis hirta ‘Variegata’ emerges in the spring with dark green leaves, accompanied by slender, bright yellow margins. When planted en masse this plant creates wonderfully dense fall foliage that reaches 18-24 inches in height, perfect for cottage gardens or in the middle of borders. And if that isn’t great enough, this plant keeps providing, with its late-summer, early-fall flowers that bloom at leaf bases. The flowers are best when you can appreciate them up close and will last for about three weeks or until a hard frost. The toad lily thrives in average to moist soils, in full to partial shade and certainly brings some joy to my day as I hope it will to yours. Photo credit: M. Rossman

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Sporobolus heterolepis (prairie dropseed)

You can smell the Sporobolus heterolepis well before you see it. The scent has been compared to coriander, buttered popcorn, or even hot wax. But for me, if the dry heat of summer had a scent, it would be this. This distinct smell is a result of the branching flower panicles on slender stems rising above the arching foliage of prairie dropseed in August through October. 

This ornamental grass is a North American native usually found in prairies, glades, and along railroads. It has fine-textured, medium-green leaves that will turn golden in the fall and bronze in the winter. It is a slow-growing and slow-to-establish plant that is worth the wait, as it is deer, drought, erosion, and air pollution tolerant. 

At the Scott Arboretum, Sporobolus heterolepis can be found in the Science Center infiltration beds, planted en masse with Verbena bonariensis (South American vervain) and Bigelowia nuttallii (Nuttall’s rayless-goldenrod) dotted throughout. It grows well here, in its preferred full sun with medium to low moisture. It is an elegant, elevate-your-senses kind of plant and I recommend stopping by to explore what the late-blooms smell like to you. Photo credit: M. Rossman

Pennisetum alopecuroides ‘Hameln’ (fountain grass)

There is just something so elegant about a grass swaying in the breeze, especially when the sun interacts with the plume-like flower heads to create a scene worthy of a landscape portrait. One particular specimen that has been adding said elegance to our gardens here is the Pennisetum alopecuroides ‘Hameln’. Also known as fountain grass, this compact perennial grass forms a clump of dense arching linear leaves. Bright green in the summer, the leaves transition into a golden-yellow during the fall before fading to beige and will remain attractive through the winter. 

However, what particularly draws me to this plant are the silvery-white bottle brush like flower spikes that develop in mid- to late-summer. These delicate, soft flowers sit well above the leaves and arch outwards looking as if they are glowing when backlit by the sun. They bloom from August to October and will turn brown as the seeds form, persisting until late fall/early winter before shedding.

The lovely fountain grass can be observed in the Scott Entrance Garden or in the Cut Flower Garden here at the Scott Arboretum and certainly adds a gentle touch to our beds.  Photo credit: M. Rossman

Chasmanthium latifolium (northern sea oats)

The new Singer Hall landscape is truly a celebration of Pennsylvania’s bioregions. As you circle around the building you will encounter an array of plants native to areas such as the piedmont meadows or the New Jersey coastal plain mixed oak forests. In many of these demonstrated bioregions you will find a striking and movement-forward grass that is audibly present in the landscape when the breeze blows.

The Chasmanthium latifolium is an ornamental grass that is native to the eastern United States and northern Mexico. It grows in Zones 3-8 and is most distinguished by its flat, dropping seed heads. Forming on arched stems, the seed heads flutter when caressed by even the softest of breezes and emerge green but transition into purplish-broze by late summer. 

This is a clump-forming grass that can grow up to a height of 2-5 feet with a spread of 1-2 feet. It prefers medium to wet soil and is one of the more shade tolerant ornamental grasses, but can certainly handle full sun. Those seed heads are not just attractive but they are functional too, as this plant self-seeds and spreads quite a bit. Chasmanthium latifolium usually are present in woods or on rocky slopes along streams or moist bluffs and here at the Scott Arboretum are richly present in the Singer Hall landscape.   Photo credit: M. Rossman

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Tune into the Gardener’s Almanac to learn what we are doing in the garden at this moment. Learn from Scott Arboretum staff which plants we are pruning, planting, weeding and which pests we are monitoring and removing right now. This virtual almanac is a great reference guide for gardeners.

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Colchicum byzantinum (autumn crocus)

There seems to be an abundance of purple interest developing at the Scott Arboretum. The Colchicum byzantinum has emerged along Magill Walk and is greeting viewers with its lovely lilac early-fall color. 

These plants have been preparing for their spector all summer long. Starting in spring the Colchicum byzantinum produces 5-6 broad, ribbed, dark-green leaves which supply the plant with nutrients. These leaves eventually turn yellow, die back, and the plant remains quiet until September when 4-6 inch tall flowers emerge. A single Colchicum byzantinum bulb may produce a clump of up to twenty flowers, creating quite the display of soft-lilac flowers with dull yellow anthers. 

Don’t be misled by its common name, autumn crocus. Although these funnel-shaped flowers may be similar to the well known spring Crocus, they are not the same. Some defining characteristics that differentiate Crocus from Colchicum are the stamens; Crocus have three, while Colchicum have six. An additional difference is that Crocus foliage occurs along with the blooms and as previously mentioned, Colchicum flowers bloom in the fall while their foliage appears in the spring. So while the common name is confusing, the Colchicum byzantinum is not just a reappearance of our lovely spring Crocus, however they are equal in their splendor and certainly add some delightful early fall color. Photo credit: M. Rossman

Callicarpa americana (American beautyberry)

In continuation of highlighting recent purple interest in the garden, it would be unwise of me to not mention the Callicarpa americana. This lovely deciduous shrub is certainly coming into its season of splendor, as its glossy clusters of fruit start to develop into magenta. Starting at the base of each arching branch and working towards the tip, the clusters of green berries that encircle the stem at each leaf axil transition from a pale green to a royal purple. These berries are rich in color and can remain attractive for a long while, if not attended to by the birds first.

The Callicarpa americana, commonly known as the American beautyberry, is a southeastern United States native and grows in Zones 6-10. It can grow from 3 to 5 feet tall, usually just as wide and will fruit most abundantly in full sun. It has elegant arching branches that create a cascading habit. 

A wonderful example of the Callicarpa americana can be found the entrance to the John W. Nason Garden and I would highly recommend seeking this specimen out to admire its purple berries before the birds beat you to it.  Photo credit: M. Rossman

Chionanthus retusus (Chinese fringetree)

The Chionanthus retusus gets most of its attention in the spring when it is covered with pure white, fragrant flowers, however, the Chinese fringetree is not a one-season-wonder. I wandered past the Scott Arboretum specimen located in the Lilac Collection, which is adjacent to the Dean Bond Rose Garden, and found that it was covered with beautiful deep-purple fruit. 

One could easily deduce that this tree is part of the Oleaceae, or olive family, due to the shape and appearance of its clusters of ½ inch long fruit. Chionanthus retusus are primarily dioecious, meaning separate male and female flowers, and when the female flowers are fertilized they give way to clusters of fruits which ripen to a dark purplish-black in late summer. These fruits are a wonderful source of food for wildlife and birds and add late season attraction. 

The Chionanthus retusus is a tree often given the status as being “tough as nails.” They are tolerant of air pollution, adapt well in urban settings, and are generally not susceptible to pests or disease. They grow in Zones 5-9 and are wonderful choices if you are looking for tough trees with multi-seasonal interest.   Photo credit: M. Rossman

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Hydrangea quercifolia ‘Harmony’ (oakleaf hydrangea)

During peak summer, the stems of the Hydrangea quercifolia ‘Harmony’ (oakleaf hydrangea) may weep under the weight of its pure white, densely compacted panicles. Beginning its lengthy flowering cycle in late-spring to early-summer, these cloud-like inflorescences delight viewers and pollinators alike. As we reach towards the end of summer however, you will start to notice the white fading into brown until the whole panicle has lost its summer brilliance. But in this transition, the oakleaf hydrangea is not yet done being of interest in the garden. The brown panicles provide a dynamic contrast against the dark green of the 5-7 lobed leaves and are attractive in their own regard. They give a preview to fall where tones become more earthy in the gardenscape.

This browning can be misleading. It is not a result of ill care or neglect, rather, it is the next step for the inflorescences. The originally white, now brown flower-like clusters on the Hydrangea quercifolia ‘Harmony’ are actually not flowers but the bracts; the sterile florets that surround the fertile flowers that are located on the inside of the panicle. It is the natural cycle of these bracts to emerge green, transition to brilliant white, and then fade into brown throughout the summer. 

As we transition into autumn the leaves of the oakleaf hydrangea will darken into a sumptuous wine-maroon. The combination of the dark leaves and the brown panicles will certainly set the mood for your autumn garden and I highly recommend embracing this later inflorescence stage. Watch this flower progress in plantings around Parrish West Circle. Photo credit: M. Rossman

Iris domestica (blackberry lily)

I stumbled upon the seedheads of the Iris domestica (blackberry lily) in the Cut Flower Garden. Being from the southwest, I was unfamiliar with the Iris domestica and its reproductive stages, and I was instantly intrigued. Receiving its common name from the blackberry appearance of the split-open seed heads, my first impression was of shiny black beads, delicately stitched together that would fashion well as earrings or as adornment on a dress. 

This Iridaceae family specimen has fan-like foliage arranged on a small, tuberous rhizome and can grow up to 18” tall. Yellow-orange short-lived flowers are born on 2-3 foot tall slender stems during July through August. The flowers then give way to pear-shaped seed capsules that transition from green to tan and eventually split to reveal the shiny black seeds arranged in clusters. While the flowers may be fleeting the seed heads are not and can remain intact for several months, providing early winter interest. Photo credit: M. Rossman

 Monarda punctata (spotted bee balm)

As you are walking up College Ave towards the Scott Arboretum offices there is a plant content in the dry gravel and the full sun. It has long lost its flowers and bracts, and now, on its square stems, there are, what look like pompoms on a string. The late stage of the Monarda punctata (spotted bee balm) is a joyful stalk, remnants of a plant that provides interest all summer long.

This herbaceous perennial is native to the eastern United States and can typically be found in full-sun areas with dry soils. It blooms from June to July and is all the fun of the species Monarda but with more blooms on each stem. Stacked inflorescences with large, leafy bracts radiate out from the stem, just below each flower head. The bracts can range in color from light pink to white, while the flowers are yellow with brown spots and are only visible close up. When spotted bee balm defoliates you are left with a set of tiered pompoms slowly wafting in the breeze.

These flowers are incredibly popular with pollinators and attract beneficial predatory wasps to the garden which help to control pesky grubs and caterpillars. A spectacular plant all around I greatly enjoy the late life cycle of the spotted bee balm. Photo credit: M. Rossman

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Persicaria amplexicaulis ‘Firetail’ (mountain fleece)

Part of my responsibility as an intern here at the Scott Arboretum is to assist with creating small flower arrangements, used in the Wister Center. Equipped with my pruners, a small glass vase, and a sense of artistic curiosity, I head out into the gardens, looking for eye-catching flowers and textural foliage. One such flower that has made its way into many of my floral compositions is Persicaria amplexicaulis ‘Firetail’ (mountain fleece). 

This herbaceous perennial is certainly long-lasting and its wonderfully rosy-red spired flowers can be enjoyed from June until early October. Rising above clumped dark green foliage, the graceful wand-like flowers appear as though they’re floating; their airy nature adding whimsey and movement to any space. A delicate dash of color that bodes well for borders, along ponds and streams, or in harmonious meadow plantings. 

This zone 4-7 plant can be grown in full sun to partial shade, in medium to wet soils. While not a bully in the landscape, it does self-seed and is best suited in locations where it has room to grow and expand. I certainly find much joy in seeing this plant in the Scott Entrance Garden and having the opportunity to use it in my arrangements, where it adds verticality, color, and of course, delight. photo credit: M. Rossman

Colutea x media ‘Copper Beauty’ (bladder senna)

I enjoy watching how others move throughout a garden space: what their eyes rest on, what plants catch their attention. One thing I notice in particular, is that when enticed by a particular plant, most people will reach out to touch it, needing that physical connection to satiate their tactile curiosity. Touch is an important key in activating all the senses in the garden, and there are certainly plants that draw more hands towards them than others. One example is Colutea x media ‘Copper Beauty’ (bladder senna).

Located in the John W. Nason Garden, this deciduous shrub demands closer inspection through its papery seed pods that develop in late summer. As the enclosed seeds ripen, the pinkish-orange pods inflate to create balloon-like bladders hanging down from the branches. One cannot help themself from reaching out to squeeze the seed pod and experience the enjoyment of this unusual reproductive stage. 

Notable apart from its seed pods, this zone 5-7 plant has orange and yellow pea-like blooms and bluish-green foliage that, all together create an airy appearance. While preferring full sun and dryish conditions, it does not perform well in hot and humid summer climates. Long blooming, the bladder senna is curious, fun, and ornamental and will certainly add delight to your space and your day. photo credit: M. Rossman

Lagerstroemia subcostata var. fauriei ‘Townhouse’ (Japanese crapemyrtle)

As the weather slowly starts to ebb towards the cooler end of the temperature range and I start to add more layers, there are some plants that have just begun to shed theirs. And what’s underneath is stunning and eye-catching.

Lagerstroemia subcostata var. fauriei ‘Townhouse’ (Japanese crapemyrtle) had shed its outermost bark and I could not be more delighted. Cinnamon red and mahogany, the colors of this bark create a fantastic tapestry that only increases in interest and intensity as you approach. The exfoliating bark lays at the base of this quite large, multi-stemmed Japanese crapemyrtle. Accessioned in 1992, this specimen is located on the south side of Trotter Hall where arboretum visitors can revel in its striking branches.

Growing best in sunny sites with well-draining soil, this plant has fragrant white flowers in mid- to late-summer and has a brief, but striking display of fall color. I highly recommend getting up close to the Lagerstroemia subcostata var. fauriei ‘Townhouse’ and experiencing this delight of color here at the Scott Arboretum. photo credit: M. Rossman

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