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One of the great things about gardeners is that no two of us have the exact same taste in plants. Some gardeners prefer neat, ordered, well-mannered landscapes, while others lean towards more of a natural, wild aesthetic. Some of us fill our landscapes with familiar, classic plants, while others gravitate towards plants that are uncommon, perhaps even unusual. Some think of gardening as mainly a springtime activity and thus their landscapes are filled with plants that bloom only in April and May, while others value color and interest throughout as much of the year as possible. As such, no two landscapes end up looking quite the same, and the world of plants provides endless opportunities for creative expression. If your tastes tend toward the unusual and unkempt, and you’re always on the hunt for plants that bloom at odd times, you will probably love Lespedeza, also known as bush clover, a sprawling shrub with purple pea-like blooms in the fall. Although there are several species of Lespedeza, the one most suitable for garden use is Lespedeza thunbergii, a variety that grows three to six feet tall and wide, although plants will usually be a bit wider than they are tall. It is worth noting that many other species of Lespedeza are generally considered weeds and sometimes appear on invasive plant lists. While Lespedeza thunbergii will drop some seedlings and does take up a fair amount of space in the landscape, it is reasonably well-behaved compared to its relatives.
The ornamental value of Lespedeza comes mainly from its intense autumn-bloom. Its long arching branches are loaded with tiny flowers from base to tip. Though obviously different in flower color, the shape of the plant creates a similar effect to plants like forsythia, which blooms golden yellow in early spring, or abelia, with its light pink flowers during summer. The flowers are frequently visited by butterflies and the occasional hummingbird. When the long branches rest against bare soil, they will sometimes root at the point of contact. Once rooted, these rooted stems can be cut off and easily transplanted or shared, if so desired. Lespedeza is native to Central and Southern China, and other parts of East Asia, and is hardy from zones 5 through 8. It typically will die back to the ground in our winters, and if you are growing Lespedeza you should plan to cut it back to the ground every spring, in order to allow it generate a flush of new growth.
 'Gibraltar' is one of the larger Lespedeza cultivars, growing six feet tall and twelve feet wide. A few of the cultivars of note include ‘Alba,’ a white-blooming variety, ‘Gibraltar,’ which is slightly larger than what is typical for the species, and ‘Little Volcano,’ which has darker rose-purple flowers. Because of its shape and growth habit, Lespedeza is a good plant to incorporate in areas where it can sprawl, such as slopes, near walls or water features, or in border areas. It is also quite drought-resistant once established, so it will do well in hot, dry areas of the landscape.
Matthew Stevens is the County Extension Director and Horticulture Agent for North Carolina Cooperative Extension’s Pitt County Center. If you have questions about this article or gardening in general, please contact the Pitt County Extension Master Gardeners at [email protected] or 252-902-1705.
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The calendar has just turned to October, and while that may mean the beginning of “spooky season” for some, it also means that cold nights are coming! It won’t be long until we have to start watching the news for frost alerts and guidance for protecting tender plants. Take some time to bring in any houseplants that are still outdoors and be prepared to protect any tender plants you want to try to squeeze a few more weeks of enjoyment out of. Inspect houseplants before bringing them indoors, to make sure you’re not carrying along any undesirable pests with the plants themselves. Along with the cold weather of fall comes a change in leaf color for many of our deciduous trees. There’s always something nice about the way the new colors paint our landscape this time of year. This change is not an accident of course, there’s a simple scientific explanation behind how and why it happens.
The changing of leaf color is caused by a physiological change that happens in the plant during fall. Leaves produce a number of pigments, the most well-known being chlorophyll. Chlorophyll is a green pigment and is the reason the leaves of most plants are some shade of green for most of the year. However, plants also contain carotenoids and anthocyanin, yellow and red pigments respectively. The amount of each pigment a plant produces depends on the temperature and the length of day. For most of the year, leaves produce much more chlorophyll than these other pigments, but in fall chlorophyll production slows down and the other pigments take over. Trees that turn yellow or orange have a lot of carotenoids present, while those that turn red have a high amount of anthocyanin.
A number of other factors seem to play at least some role in how brilliantly the colors of fall shine in any given year. One is rainfall. Colors often seem to be more intense if the weather has been dry and sometimes aren’t expressed as vibrantly if there’s been a lot of rain. his can also dictate when the color change happens, as it may occur slightly earlier in dry years than in wet ones. The weather also affects our perception of the colors as well. Colors appear brighter to our eye on clear days than on cloudy ones, so if it is rainy during peak foliage season, it may not be as impactful to us as viewers.
Though we think of fall foliage primarily as a forest phenomenon, many of the deciduous trees and shrubs we use in our landscapes go through the same color change just prior to their leaf fall. Don’t neglect this characteristic when selecting plants to include in your landscape, as fall leaf color can have incredible ornamental impact at a time of year when flowers are sparse. Matthew Stevens is the County Extension Director and Horticulture Agent for North Carolina Cooperative Extension’s Pitt County Center. If you have questions about this article or gardening in general, please contact the Pitt County Extension Master Gardeners at [email protected] or 252-902-1705. This week, let’s round out our discussions of fall-blooming perennials by considering the aster. Asters, botanically known as Symphyotrichum after a recent name change, are a genus of plants in the Asteraceae family (who would’ve guessed), also known as the daisy family. Their late arriving blooms are a welcome sight in fall gardens, and with flower colors mostly on the blue-purple edge of the color wheel they make a fabulous pairing with yellow and orange blooming fall plants such as goldenrod and assorted chrysanthemum varieties, which I mentioned in previous columns. Let’s look closer at a few of the most prominent species of Aster. We’ll start with Symphyotrichum novi-belgii, known commonly as the New England or New York Aster, a species native to the east coast from Canada to Alabama. It is a herbaceous perennial (it dies to the ground in winter and returns in spring from its root system) with lavender purple petals that radiate from a yellow center, forming its disk-shaped daisy flower head. This aster is often found growing in salt marshes and other moist habitats in coastal areas. In garden settings it requires moist, but well-drained soil, and flowers best in full sun. It is a tall, upright grower, reaching 3 to 5 feet high and only 1-2 feet wide, and though the species is lavender in bloom, cultivars such as ‘Peter Harrison’ and ‘Royal Ruby’ offer pink or red blooms with otherwise similar attributes.
Top right: Symphyotrichum novi-belgii 'Peter Harrison' has pink blooms. Bottom right: Symphyotrichum novi-belgii 'Ruby Red' has deep red blooms. Symphyotrichum laeve, or Smooth Aster, is slightly smaller at 2-4 feet high and wide, but otherwise fairy similar. Its native range extends a bit further west into the central part of the country, and is probably slightly more drought tolerant than the New England Aster. Both are quite tolerant of nutritionally poor soils. Next is Symphyotrichum ericoides, or Downy Aster. This is a white-blooming species native to Canada, the central United States, and northern Mexico, typically found in fields, clearings, roadsides, and dry thickets. It’s a bit smaller than the other species mentioned so far, at a height of 18-36 inches tall and 12-18 inches wide. The Downy Aster tolerates shallow, rocky soils quite well, and is actually very useful in preventing soil erosion when grown or planted on slopes. This species has white flowers rather the blue and purple so many other asters are known for. The cultivar ‘Snow Flurry’ grows as a groundcover, creating a dense mat of white flowers 4-6 inches above ground.
Above left: Symphyotrichum laeve: The blooms of these Smooth Asters are from a second year plant. Photo: Tom Potterfield, CC BY-NC-SA 2.0 Above right: Symphyotrichum ericoides: The Downy Aster has white flowers. Dan Mullen, CC BY-NC-ND 2.0 As native species, asters are an important part of our ecosystem and attract a number of different insect pollinators. They also provide food for birds and other animals. Pearl Crescent butterflies are known to frequent both the New England and smooth aster, as are a number of different native bee species. Songbirds and small mammals such as squirrels and chipmunks feed on the seedheads that persist after flowering, so consider leaving those throughout the winter before cutting the plants back in spring. Asters can be incorporated in the landscape in mixed perennial gardens, borders, pollinator gardens, native plant gardens, and rock gardens.
Matthew Stevens is the County Extension Director and Horticulture Agent for North Carolina Cooperative Extension’s Pitt County Center. If you have questions about this article or gardening in general, please contact the Pitt County Extension Master Gardeners at [email protected] or 252-902-1705. To continue with the theme of fall-blooming perennials established with my article about chrysanthemums, I’d like to talk about goldenrod. There are several species of goldenrod within the genus Solidago, most of which are native to North and South America. The genus name Solidago comes from the Latin word solidus, meaning to make whole, and is a reference to the medicinal uses of Solidago that were a common practice among many Native American tribes. Perhaps the most familiar species of goldenrod is Solidago canadensis, which is native throughout much of Canada and the United States. This species of goldenrod is a herbaceous perennial with arching branches and grows to a height of 2 to 6 feet tall, with a width of about 4 to 6 feet. The characteristic golden yellow flowers begin to emerge in August and last through October. As the blooms conclude, brown seed capsules covered in whitish-gray hairs develop. Goldenrod has been unfairly maligned as an allergen because of the vague similarity that these seed capsule clusters have to bloom of ragweed, blown pollen of ragwort, and other high allergen plants. In fact, goldenrod produces pollen that is much denser and damper than the light windblown pollen of ragwort and other high-allergen plants, and therefore isn’t particularly of concern in that regard. It is, however, a favorite of bees and other pollinators, and an important one at that, as there are relatively few pollen and nectar sources in the fall compared to spring and summer.
Top left: ‘Fireworks’ is an especially popular compact cultivar and diminutive species of goldenrod. Bottom left: Solidago flowers and leaves. Photo: David J. Stang, CC BY-SA 4. Right: The most familiar species of goldenrod is Solidago canadensis. Solidago rugosa, or rough goldenrod, is a slightly more compact species, growing 3-4 feet high and wide. The common name, rough goldenrod, refers to the stems lined with stiff hairs. For many gardeners, this compact form is a bit easier to find space for in the landscape, and the floral impact is just as substantial. The cultivar ‘Fireworks’ is especially popular, and is even more diminutive, at about 2-3 tall and wide. The flowers radiate in all directions and resemble a burst of fireworks, hence the name.
All species of goldenrod are fairly adaptable, but prefer full or mostly sunny conditions and average soil. The plant will, however, tolerate drought and low-fertility soils. It can be used in the landscape in natural areas, native gardens, pollinator gardens, and as a companion plant to other fall-blooming plants such as mums and asters. Compact cultivars such as ‘Fireworks’ can be used in edging pathways, in the front of perennial borders or foundations, and even in large containers. Matthew Stevens is the County Extension Director and Horticulture Agent for North Carolina Cooperative Extension’s Pitt County Center. If you have questions about this article or gardening in general, please contact the Pitt County Extension Master Gardeners at [email protected] or 252-902-1705. Autumn is approaching quickly, and one of the landscape plants we most commonly associate with the fall is the chrysanthemum, frequently referred to simply as 'mum.' Fall flowers are often in short supply, compared to the relative abundance of blooms in spring and summer, and yet reliably year after year, chrysanthemums are the shining star of fall landscapes with their late-arriving blossoms. Chrysanthemums are short-day blooming plants, meaning their bloom is triggered by the shortening length of daylight and increase in length of darkness that occurs each fall. They are members of the Asteraceae, or daisy, family, with flowers resembling the classic disk-shape we associate with daisies. Many of the mums we buy and plant in the fall are herbaceous perennials, though gardeners treat them like annuals, ripping them out after the flowers have succumbed to frost.
Though there are several different types of chrysanthemums, and thousands of cultivars, all of the mums we use in North Carolina like essentially the same conditions, preferring well-drained, high organic matter soils in full sun. They will do okay in a small amount of shade, too, and an hour or two of late afternoon shade may even be a good idea, but more than that will reduce the amount of blooms you see. Mums do use a fair amount of water, particularly large, container-grown mums, but they don’t like to be in wet soil, so adequate drainage is quite important. If you’re planting mums this fall and want to overwinter them, you will need to do a bit of work in the spring and summer to duplicate the show you get in year one. Container-grown mums are pinched back repeatedly throughout the growing season in order to develop large dome-shaped plant shapes and they will need to be pinched back that same way in subsequent years in order to grow to the same size and shape the following year. Even the so-called hardy mums, which are treated more like traditional perennials, including cultivars such as ‘Sheffield Pink’ and ‘Mary Stoker,’ should be pinched back for peak performance.
Use mums in your landscapes in containers or in the ground, in lining walkways, edging along the front of a border area, or along a wall or other high-visibility areas. Mums can also be used as companion plants with asters, ornamental kale and cabbage, and other plants that stand out in the fall. Mums can develop some leaf spot fungal diseases, but avoiding watering the foliage and instead directing water to the root area of the plants will lessen those issues.
While mums have relatively low toxicity, there is an oil in the leaves and flowers that can cause redness and irritation in some individuals sensitive to the compound. There is also a natural insecticide made from an extract from chrysanthemum flowers and seeds. Matthew Stevens is the County Extension Director and Horticulture Agent for North Carolina Cooperative Extension’s Pitt County Center. If you have questions about this article or gardening in general, please contact the Pitt County Extension Master Gardeners at [email protected] or 252-902-1705. |
Matt Stevens
Pitt County Extension Director & Horticulture Agent Archives
January 2025
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