Gardening

Gorgeous Grasses

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By Dawn Pettinelli, UConn Home & Garden Education Center

Autumn shines a spotlight on ornamental grasses. With their rustling blades and fluffy seedheads they are star performers in late season gardens going head-to-head with asters, mums, Montauk daisies and boltonias. Plus, they are great in fresh or dried cut flower arrangements.

The huge selection of grass species available is great for gardens but makes selecting difficult. Heights range from a few inches to more than 6 feet; colors from deep green to chartreuse, burgundy to black. Solid or variegated?  Would a clump former, spreader, or self-seeder best fit your needs? Are seed heads important for fall and winter interest? Is this grass planted as an ornamental feature in your garden bed or landscape or are you looking for natives to support pollinators and perhaps serve as food for birds and others? Answers to these questions may guide you in grass selection.

Two favorite non-natives grown for their ornamental value are cultivars of Miscanthus and Pennisetum. While the miscanthus species has been listed as potentially invasive in CT, a number of attractive cultivars are available for purchase and can be striking if well positioned in the garden. Two outstanding selections are ‘Gracillimus’ and ‘Zebrinus’. The first has shimmering silver veined green leaves growing in graceful mounds. Reddish flower plumes emerge in fall changing to a light silvery hue. Plants are clump formers but can reach 6 feet or more in height.

‘Zebrinus’ is more commonly known as zebra grass for its definitive yellow and dark green striped foliage. This plant gets big over time. Mine is now 6 feet across and probably 10 feet high. I wrap a rope around it in the late summer to keep it upright through fall rains and winds. Stalks have been used quite effectively as a substitute for cornstalks around the lamppost.

Pennisetum alopecuroides
Pennisetum alopecuroides. Photo by dmp2024

My Pennisetum alopecuroides was grown from seed probably 20 years ago. These plants are absolutely gorgeous in the fall. Despite the many bottlebrush seed heads, I’ve never found a seedling. The fine, arching foliage resemble flowing water hence the common name, fountain grass. Cultivars of this graceful, flowing grass range from 18 inch ‘Piglet’ to 5 foot ‘Fox Trot’.

Native grasses are soaring in popularity and much easier to find at garden centers than they used to be. One switchgrass (Panicum virgatum) cultivar, ‘Heavy Metal’, is quite popular for its upright, striking blue-green foliage. If happy, it can reach 4 to 5 feet in height. The wheat-colored seed plumes are attractive to us during the gloomy winter months but also as a food source to a number of bird species.

Little bluestem (Schizachyrium scoparium) is a favorite also of humans and wildlife, including both birds and butterflies. This upright native grass is pretty ubiquitous along roadsides and in fields and meadows. New growth begins a clean blue green but, by the end of the growing season shifts to deep bronze and chestnut hues. This is a tough plant content in sandy soils and reaching about 2 feet in height. The silvery seed tuffs are retained for most of the winter. Little bluestem combines well with a number of perennial wildlings like rudbeckia, pearly everlasting, goldenrod and species of asters.

Chasmanthum latifolium
Chasmanthum latifolium. Photo by dmp2024

Also commonly found along roadsides, purple lovegrass (Eragrostis spectabilis) grows on sites from full sun to part shade. This is a very well-behaved grass in the Poa (bluegrass) family. It is native to eastern and central U.S. and produces those airy pink seedheads you might admire as you drive.

Northern sea oats (Chasmanthium latifolium) has very distinctive, but attractive seedheads. Native to the eastern and southern parts of the U.S., it is hardy from zone 5 to 8. Northern sea oats is a clump former with showy panicles of flowers in late summer that mature into wide, drooping seedheads. This grass likes moist but well-drained soils and is a larval plant for several species of butterflies as well as serving as a food source for several mammal and bird species.

Other native grasses worth investigating include side oats grama (Bouteloua curtipendula), big bluestem (Andropogon geradii) and prairie dropseed (Sporabolus heterolepsis). Check out both native and exotic ornamental grass offerings for their varied textures, colors, forms and flowers.

For more information on growing ornamental grasses or selection or for other gardening questions, contact the UCONN Home & Garden Education Center, toll-free, at (877) 486-6271, visit their web site at www.homegarden.cahnr.uconn.edu or contact your local Cooperative Extension Center.

I Want My Mum: A Fall Classic Through the Ages

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By Abigayle Ward, UConn Department of Plant Science & Landscape Architecture Graduate Student

A group of fall flowers mixed with mums in a container.
Orange, purple, and white mums used as “filler” in a potted arrangement at Wickham Park in Manchester, CT. Photo by Abigayle Ward.

With the arrival of fall, one popular bloom brings the brilliant colors of forest foliage to our doorstep: With flower colors coming in purple, red, orange, yellow, and more, chrysanthemums, or more simply, mums, have been a favorite for centuries. First domesticated in China over 3,000 years ago, mum roots, seedlings, and flower pedals were used as herbal remedies in traditional Chinese medicine.

For nearly 2,000 years, mums have been the symbol of fall in Chinese culture: The Double Ninth Festival, celebrated on the ninth day of the ninth lunar month, celebrates harvest, ancestors, and the beauty of autumn, with mums taking center stage as both decorations, accessories, and a floral wine.

First introduced to Europeans in the 1600s, mums quickly became a fall favorite. By the mid-1800s, the Victorians had written extensive literature on the interpretation and meaning of the color of each bloom. While some colors have carried the same meaning for thousands of years – such as white blooms symbolizing mourning – others took on entirely different meanings. While in China, a red mum represents fortune and luck, a Victorian would interpret this as a declaration of love.

Luckily, it seems many home gardeners in the United States nowadays are more concerned with the aesthetic appeal of their blooms than the meanings, so major misunderstandings are avoided. With several thousand cultivars available, mums come in many color combinations and growth habits. The National Chrysanthemum Society of the USA recognizes 13 different flower classes, ranging from 6-inch diameter flower balls with many layers of florets to smaller, 2-inch diameter flowers with only a single layer of a few petals. Some mums bloom early, in August, while others will bloom in October.

A row of potted mums for sale on a bench
Mums can be found for sale at garden centers starting in late summer. Photo by dmp2024

Further, some mums are annuals regardless of USDA hardiness zone, while others are perennials in zones 5-9. While so-called “florist mums” or “pot mums” are generally grown as annuals and will not survive winter frost, “garden mums” can survive winter frost if planted early enough in the growing season. If you wish to purchase a garden mum, but the mums are unmarked, a good way to tell the difference between florist and garden mums is to check for stolons near the base of the plant. Stolons, also known as “runners”, are shoots that grow out from the base of the mother plant. A daughter plant may have roots growing from the end of a stolon. If you want to purchase a perennial mum, check around the base of the stem for stolons – they will most likely be quite short but are a good sign that the plants may overwinter successfully. Alternatively, if you want to be sure you grow a permanent mum installation that comes back year-after-year, you can start some varieties of hardy garden mums from seed in late winter prior to planting out in spring. Get any mums you want to try overwintering in the ground as soon as possible. You can plant mums next year in spring or summertime to give them plenty of sunny weather to grow hearty root systems prior to the first winter frost of 2025. Mulch around your fall planted mums to help insulate their roots from frost.

Both annual and perennial mums benefit from at least 6 hours of direct sunlight per day. In Connecticut, a sunny spot to the south of your home would be ideal. Water mums thoroughly once the topsoil is dry but try not to wet the leaves or the flowers. Water left on the leaves or flowers can make mums prone to fungal diseases, which can make them unsightly or even kill them in severe cases. Towards the end of the season, especially between October and November, consider leaving the blooms on as long as possible to allow late-season pollinators to collect nectar.

Whether planted in a permanent flower garden or kept in a pot on the porch for fall, mums are an excellent addition of rich fall colors to any home gardener’s flower collection. Consider picking some up this season at your local garden center or plan on purchasing plants or seeds next year.

If you have a question on caring for your mums or for other gardening questions, contact the UCONN Home & Garden Education Center, toll-free, at (877) 486-6271, visit their web site at www.homegarden.cahnr.uconn.edu or contact your local Cooperative Extension Center.

Tips from UConn Floriculture Help Spruce Up Container Plantings

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By Dawn Pettinelli, UConn Home & Garden Education Center

Fall container plant selection at a greenhouse
Photo by dmp2024

As summer wanes and the cool breezes of autumn begin to roll into Connecticut, it’s the perfect time to refresh your container plantings. Shelley Durocher-Nesta, UConn Plant Science Floriculture Grower, says this summer’s rain and high temperatures have many of our container plantings looking a little ragged but fall presents a unique opportunity to infuse your outdoor spaces with rich colors, interesting textures, and seasonal charm that lasts well into the cooler months

By the end of summer, many annuals start to fade. To maintain a lush and lively look, she suggests replacing them with plants that thrive in cooler weather. A top candidate for fall plantings, both containerized and inground are mums, obviously. They offer an explosion of color in shades of yellow, bronze, pink and reds. Asters are runner’s up, flashing their cooler shades of purples and pinks.

Ornamental cabbages and kale are leafy plants bringing texture and interest to plantings, often with their lacy ruffled edges. Hues range from deep purple to violet and from white to green, some being two-toned.

Recently, pansies and violas have been showing up as fall bloomers. These delicate flowers add a pop of color and laugh off light frosts. Pansies, with their cheerful ‘faces’ are particularly popular and come in a wide range of colors. Ornamental peppers in shades of yellow, purple red and orange are also available often in 4-inch pots

Depending on your color scheme and container size, two other great fall accompaniments are heuchera (coral bells) with their stunning foliage in a myriad of colors, and sedums that can be used either for their unique fleshy foliage or pollinator-friendly blooms.

Don’t forget ornamental grasses for their attractive seedheads and whispering foliage. If pinched for room, a few stalks of dried grasses or wheat can give your containers a rustic, harvest-time feel.

Before purchasing new plants, access the plants presently in your containers. Groom, deadhead and cut back leggy annuals like petunias and verbena. If you have summer plants that are still thriving, you can repurpose them by combining them with fall plants in the same container for a mixed-season look. However, often one finds that their summer layout doesn’t work as well with new plants. Don’t hesitate to replace staid offerings. Durocher-Nesta, agrees saying that switching out her summer planters that are getting a little tired by the end of August is a joy.

Container full of fall annuals
Photo by dmp2024

Refresh the soil in containers before planting new fall selections. Summer plants have depleted the nutrients, so replacing the top few inches with fresh potting mix can get fall plants off to a better start. If your container is large and you can’t replace all the soil, mix in some compost or at least a slow-release fertilizer, as directed on the package, to rejuvenate it,

Consider elevating some containers on stands or steps to create varying heights. Grouping containers of different sizes together on your porch or patio can also add depth and visual interest.

One of the joys of fall container gardening is the chance to play with a different color palette. While summer is about bright, vibrant colors, fall offers a more subdued, warm earthy palette. Think deep purples, burnt oranges, and rich reds, balanced with greens and whites.

As the weather cools, plants will need less water but check regularly. Container plants can dry out quickly especially on sunny fall days. Stick a finger in and add water when the top inch of potting media feels dry.

Regularly deadhead spent flowers and remove any yellowing leaves to keep your containers looking tidy and to encourage continued blooming. As frost becomes more likely, be prepared to cover sensitive plants or bring containers indoors on particularly cold nights.

In addition to the plants, fall-themed accents can enhance the seasonal appeal of your containers. Consider adding small pumpkins, gourds, or decorative squash to the mix. For a touch of whimsy, add seasonal decorations like mini scarecrows, wooden sunflowers or decorative berries.

Sprucing up your container plantings for fall in Connecticut can bring a fresh, seasonal look to your outdoor spaces. With the right plant choices, thoughtful arrangement, and a few seasonal accents, your containers can remain a focal point of beauty and interest well into the cooler months. Durocher-Nesta shares thoughts about her favorite fall flower: “Bright and fresh mums bring a smile to my face during a time of year when falling leaves and shorter days mean winter is coming.  They’re one last Hoorah! for the growing season.”

If you have questions on container plantings or on any other home or garden topic, contact the UCONN Home & Garden Education Center, toll-free, at (877) 486-6271, visit their web site at www.homegarden.cahnr.uconn.edu or contact your local Cooperative Extension Center.

Fall is a Fabulous Time to Plant!

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By Heather Zidack, UConn Home & Garden Education Center

Evergreens for sale at a nursery
Photo by H. Zidack

There’s no doubt that spring planting is exciting. The instant gratification that comes with putting in our new gardens and seeing flowers and greenery right away is unmatched.  Late season planting is a different animal altogether. There’s a slower pace, less pressure for perfection, and a promise of beauty next season – leaving us the chance to take up other projects in the spring.

Many gardeners will start planting hardy bulbs this fall, but you can do so much more! Planting trees, shrubs, and perennials in the late summer/early fall provides enough time for plants to get established without the heat and drought stresses of summer. New plants installed in the fall have enough time to develop healthy roots and settle in before winter. Allow at least 6 weeks (about 1 and a half months) before the first hard frost to ensure strong establishment. It’s less stressful for plants, but also easier for gardeners to plant, water, and support our gardens when the weather is a bit cooler.

Your fall planted perennials, trees and shrubs will also flower “on time” next spring. Whether you've noticed it or not, flowering plants that we buy during the growing season are sometimes manipulated to bloom when you see them on the shelf. And while most plants will settle into their natural flowering cycle after their first year, planting in the fall ensures that you are starting the season with a bed that will bloom as nature intended.

Watering a shrub after planting
Photo by dmp2024

Keep a keen eye out for garden centers that may be trying to sell down their stock, so they don’t have to keep it during the winter. Plants may look a little more weathered, and past their prime. But don’t fret! If you shop smart, you can find some great plants for fantastic prices.

Shop for plants that have a nice form and strong root ball. Avoid plants that have apparent injury to trunks or branches. Old insect feeding damage, off colored leaves, or some drought damage may be recoverable. Remember that perennials will be cut back before their next flush, and deciduous shrubs will drop leaves and need pruning regardless of what they may look like right now. Never buy a plant that seems to have issues that you cannot identify, regardless of the bargain. If there are plants that you want that are unavailable, leave space for them to be planted next season.

The lower stress environmental conditions also make it a suitable time to transplant or divide plants that bloom in the spring or summer. When digging plants for transplanting, make sure to dig wide and deep to get as much of the root ball as possible. Division is a common practice with perennials and is as simple as driving a shovel through the center of the plant and digging out half of it to put somewhere else. Larger plants can be divided multiple times.

While it may seem like a promising idea to help push your plants along with some robust growth, fertilizing is not recommended in the fall. Pushing tender growth too close to chilly weather can leave the plant vulnerable to environmental damage, loss of shoots, and possibly even loss of flowers next season. Maintain them with adequate watering and supportive care. Provide good sanitation by removing and disposing of any questionable leaves that fall in your space, especially those from newly installed plants.

Planting in the fall and supporting your fall garden will help you lay a foundation for a successful spring.

If you have questions on fall gardening or on other gardening topics, feel free to contact us, toll-free, at the UConn Home & Garden Education Center at (877) 486-6271, visit our website at www.homegarden.cahnr.uconn.edu or contact your local Cooperative Extension center.

 

End of Season Strawberry Renovation

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By Dawn Pettinelli, UConn Home & Garden Education Center

Strawberry row
Strawberries before renovation at the end of the season. Photos by dmp2024

Strawberry row after renovation
Strawberries after renovation at the end of the season. Photos by dmp2024

So, you decided to grow some strawberries this year. You carefully prepared the bed and have enjoyed your first crop. Now you are wondering what to do to keep your strawberry bed healthy and productive. In part, the care after harvest depends on whether you are growing June bearing or day neutral (everbearing) varieties and what kind of row systems you have them planted in.

June bearing strawberries are most commonly grown in what is known as the matted row system. Mother plants are set 18 to 24 inches apart in 3 to 4 1/2 foot rows and runners are allowed to root anywhere within the row. This system is usually the easiest to maintain. Typically, at the end of the third growing season both plant quality and fruit quantity start to decrease and the whole bed is dug up and replanted with new disease-free strawberry plants. Try to incorporate this into your garden rotation plan to reduce disease problems.

June bearers can also be grown in single rows composed of different aged plants with the original plants set about a foot apart. A second row is started with first year runners and set 18 inches from the initial planting. Use only the first or second daughter plants produced along the runners because they are the most vigorous and productive. The rest are usually discarded.

The next year a third row is made again using the first one or two daughter plants and once more surplus runners and plants are removed. After the original mother plants have produced fruit for about 3 years, they are generally replaced with new, disease-free stock and the cycle continues. This way one always has a row or two of strawberries in production. Ideally the row with the new strawberry plants should be located on a section of the garden where strawberries haven’t been grown for 3 to 5 years. This isn’t always possible in small yards, which is why it is important to purchase certified virus free stock.

After year two when June bearing strawberries have finished producing their crop, it is time to renovate. According to Evan Lentz, UConn Fruit Specialist and Assistant Extension Educator, renovating your June-bearing strawberries is one of the best ways to maximize your annual production, reduce disease instance, and maintain an orderly planting. Proper renovation ensures that you set yourself up for success in the following year and allows you to extend the life and productivity of this semi-perennial crop. This is doubly important for individuals producing fruit in an organic or no-spray system.

This can be done sometime in July through August. Lentz suggests starting by either mowing or clipping with hand trimmers all the foliage about 2 inches or so above the crowns. Next, go through the bed removing all weeds, and weak and extra strawberry plants and dead or dying leaves. Thin to space plants at least 10 to 12 inches apart and cultivate around these remaining plants.

Now is the time to fertilize your strawberries whether beds are renovated or not. Lentz recommends working in about 3 to 4 pounds of 10-10-10 or its organic equivalent per 100 square feet. Lightly scratch the fertilizer into the soil. Brush or rinse any fertilizer off leaves at the salts will injure them.

Day neutrals, such as ‘Tristar’, ‘Seascape’ and ‘Mara des Bois’ produce a fairly decent size crop in June and continue forming occasional berries until frost. Unlike June bearers which develop fruit buds in late summer and early fall, the ever bearers have the ability to form fruit buds throughout the summer. An advantage to growing day neutrals is you will still get strawberries even if a late spring frost kills their initial fruit buds.

In general, day neutrals are grown for 2 or 3 years and then a new batch of strawberries is planted. The day neutrals produce far fewer runners than the June bearers. The new daughter plants should all be removed although they can be transplanted into another area if desired. Plants are usually set one foot apart in single rows about 18 inches wide.

According to Lentz, all strawberries require at least an inch of water per week for vigorous growth. If dry weather sets in, plan on irrigating plants, especially those just renovated. Use a mulch of pine needles, straw or wood shavings to conserve moisture, keep weeds down and berries off the soil. Since strawberries are shallow rooted, it is important to keep weeds under control.

It does take a little time to maintain a strawberry bed but the luxury of picking your own berries for strawberry shortcake, jam or fresh eating makes it all worthwhile. If you have questions about growing strawberries or on any other home or garden topic, contact the UCONN Home & Garden Education Center, toll-free, at (877) 486-6271, visit their web site at www.homegarden.cahnr.uconn.edu or contact your local Cooperative Extension Center.

Spectacular Sedums: Your New Favorite Groundcover

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By Abigayle Ward, UConn Dept. of Plant Science & LA Graduate Student

A bee on a cluster of pink sedum flowers
Sedums are very attractive to pollinators. Photo by dmp2024

With varieties native to North America, tolerance to frigid temperatures down to minus 40 degrees F, and nearly 500 species described, sedums subvert all expectations of a succulent. Also known as stonecrop, sedums have been a garden favorite since the 17th century, and it’s easy to see why. Their visual interest and tolerance of harsh growing conditions make them well-suited as groundcover for the landscaper with an artistic eye.

You can purchase either tall or creeping varieties of sedums. Also known as ‘clumping’ varieties, tall sedum varieties can grow up to 3 feet tall although many will only grow to 1 foot tall or less. Tall, top-heavy varieties can be prone to falling or flopping over especially if overfertilized or if they receive too much water. They are well-behaved perennials that are clump formers, and thus can be useful as focal points in garden beds. Alternatively, creeping varieties of sedums grow from 2 to about 6 inches tall.  These creeping varieties will spread a few feet in every direction but do so very slowly. If you wish to fill your bed with sedums, you can stick vegetative cuttings throughout the area you want them to grow. Keep moderately moist until well rooted. Once they root, they will usually fill out your bed fairly rapidly.

With such a large variety of leaf shapes and sizes, interesting bed textures can also be created with sedums. Some varieties have large, broad, spoon-shaped leaves while others have many short, pointed leaves surrounding the main stem. You may wish to combine different textures together into one bed to make a wild, visually striking design, or try taking advantage of certain textures for specific locations in the bed. For example, you could choose short creeping varieties with small leaves for bed edges, and select slightly taller creeping varieties with larger, broader leaves to build up to the bed’s focal point.

Variegated sedum with yellow flowers
Some sedums come in a variety of leaf shapes and colors. Photo by dmp2024

Sedums come in a smattering of delightful color combinations from electric green to deep purple, red to teal; there’s a color of sedum for any design. Many keep their color year-round, and produce delightful bunches of tiny, colorful flowers between summer and fall, depending on the species or cultivar. The magenta, yellow, and lilac-colored petals attract pollinators in great numbers, especially between August and September here in Connecticut. The flowers persist until wintertime, when they dry out and turn brown as the plant goes dormant. While you may choose to remove the flowers before the winter snowfall, you can also leave them on the plant to add some color contrast in your garden as the brown stalks are surrounded with snow. Additionally, leaving the dried flowers on the plants may help creeping varieties spread, as the tiny seeds fall to the ground and germinate come springtime.

While generally very tolerant of adverse growth conditions, sedums do best in sunny spots with well-drained soil. Luckily for those of us in Connecticut, many of our soils are well-drained. Sedums require little nutrients to thrive and typically are happy with just a spring application of an all-purpose garden fertilizer. Since sedums go dormant in the winter, no fertilizer should be applied later in the year. While other groundcover plants may need water in a drought, sedums, like most succulents, can go extended periods of time without supplemental irrigation. To top it off, their foliage is bitter, and thus unlikely to be damaged by grazing wildlife. The limited maintenance requirements of sedums make them attractive candidates for both lawn alternatives and green roofs alike.

While resistant to consumption by mammalian wildlife, the juicy sedum leaves are sometimes appealing to hungry aphids and thrips. To manage aphids and other sap-sucking insects, you can simply spray sedums with water to knock off the pests – just be mindful of overwatering, as the sedums may rot. Alternatively, you can try attracting ladybugs and other aphid predators to your sedums by planting marigolds, dill and other predator attracting plants nearby. The ladybugs will partake in the pollen and snack on the sapsuckers. Avoid spraying insecticides, as they will kill both pests and beneficial insects, including pollinators. Leaving leaf litter in your garden over the winter gives a place for ladybugs to hibernate. Come spring, newly hatched ladybug larvae will be on the hunt for a meal, ready to vigilantly defend your sedums from attacking aphids.

Your next groundcover selection can be both visually appealing and low maintenance. If you’re looking to update your groundcover, consider picking up some sedums at your local garden center in the spring or summer.

If you have questions on growing sedums or on other gardening topics, feel free to contact us, toll-free, at the UConn Home & Garden Education Center at (877) 486-6271, visit our website at www.homegarden.cahnr.uconn.edu or contact your local Cooperative Extension center.

Flock to Phlox

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By Dawn Pettinelli, UConn Home & Garden Education Center

Purple phlox flowers
Purple phlox in bloom. Photo by dmp2024

About now, many of our perennial gardens are looking a bit lackluster. Early summer bloomers have fizzled out and autumn charmers like asters and mums have yet to pop. Garden phlox (P. paniculata) to the rescue!

Annual and perennial phlox comprised about 70 different species, many of which are native to North America. Their habitats range from woodlands to meadow and their growth habits from low and mounded to tall and upright. All have clusters of tubular flowers that are exceptionally attractive to hummingbirds and hummingbird moths along with bees and butterflies.

There are an outstanding number of garden worthy cultivars. My favorite is ‘David’, a white, powdery mildew resistant variety that grows to about 4 feet with loads of slightly fragrant blooms. I have it planted in my white garden and this sturdy, upright plant has come back year after year with virtually no problems.

UConn Plant Science & Landscape Architecture professor, Dr. Jessica Lubell-Brand noted phlox ‘Jeana’, the 2024 Perennial Plant Association’s Perennial Plant of the Year, is treasured for its long blooming period as well as its butterfly luring abilities. Plants can reach up to 5 feet in height and its more loose and wild appearance works well in cottage gardens featuring attractive pink flowers and decent powdery mildew resistance.

Sometimes shorter varieties are a better fit and if that is the case, for your beds look to ‘Coral Crème Drop’, which according to Dr. Lubell are part of the Candy Store series. She raves about their vibrant coral blossoms with their August feel. Another top garden candidate in her book is ‘Glamour Girl’, also with hot coral blooms as well as good resistance to powdery mildew.

A number of garden phlox sport distinctive eyes. ‘Bright Eyes’, as the name implies is a delicate pale pink with a bright crimson eye while ‘Laura’ is a mildew resistant, royal purple variety with a white eye. Both grow to about 3 feet in height.

Many gardeners find these phlox indispensable for August into September color in the perennial garden. They are tough, colorful, vigorous plants that are hardy and relatively long-lived. They make excellent background plants for narrow borders and can bridge the gap between varied sized perennial plantings. Garden phlox come in a wide range of hot and cool colors ranging from white and light pinks, to purples, reds, oranges and magenta.

For healthy, vigorous plants, they should be grown in full sun to part shade. Phlox enjoy a moderately fertile soil with a pH in the 6s. While established plants are fairly drought tolerant, larger and more numerous flower heads are produced when adequate moisture is supplied. They grow at a moderate rate so division every 3 to 4 years is usually sufficient.

Both to encourage sizable blooms as well as to reduce the incidence of phlox’s number one nemesis, powdery mildew, Dr. Lubell recommends reducing the number of stalks early in the growing season to 6 to 8 per plant. This provides better air circulation to plants.

Powdery mildew on phlox leaves
Powdery mildew on phlox leaves. Photo by dmp2024

Powdery mildew is a fungus disease that is more widespread during humid, wet summers. It typically does not kill plants, but they look awful with their leaves covered with what looks like white powder. Two options for dealing with this disease according to Dr. Lubell, are to select resistant phlox cultivars or to pre-emptively spray with a least toxic substance like potassium bicarbonate or your fungicide of choice. As stems die or get killed by frost, be sure to remove them from the garden and put in the trash, not the compost pile.

Insects are not usually a problem but during dry, hot summers, spider mites may attack plants. Usually, a strong blast from the hose will knock them off. This may need to be repeated several times if dry weather persists.

A key gardening practice when growing phlox is dead-heading, or removal of spent flower heads. Garden phlox produce a lot of seeds and if left to fall to the ground and germinate, vigorous plants will most likely produce blooms in that undesirable, muted magenta color. Often these seedlings crowd out the more desirable cultivars that were intentionally purchased.

Not only are garden phlox cultivars pretty spectacular on their own but Dr. Lubell says they pair nicely with a variety of other perennials including lilies, yarrow, ballon flower, daylilies, bee balm as well as numerous annuals.

If you have questions on garden phlox or on any other gardening questions, feel free to contact us, toll-free, at the UConn Home & Garden Education Center at (877) 486-6271, visit our website at www.homegarden.cahnr.uconn.edu

Current Landscape and Garden Conundrums

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By Pamm Cooper, UConn Home & Garden Education Center

Here at the UConn Home & Garden Education Center we have been getting questions about three pests that have been particularly widespread in the state. Whether in the landscape or the garden, there is always something going on, good or bad, and keeping up with pests or perceived pests can be challenging. The following reflect the most common inquiries we have had over the past few weeks.

Asiatic garden beetles found in a spoonful of soil
Photo by Pamm Cooper

Asiatic garden beetles have been a real problem for many gardeners this year. An imported pest, these small, rusty brown, night-feeding pests can devastate plants overnight then disappear during the day. Leaving you to wonder what is eating your plants. Favorite plants include dahlias, basil, zinnias, sunflowers, peppers, eggplants and goldenrods. They will feed on over 100 herbaceous and woody plants. In the evening a plant can look great, and the next day it can be a skeleton of stems and leaf veins.

Check damaged plants at night with a flashlight; if they are active, you should find them. During the day, dig an inch or so into the mulch and soil under damaged plants. These beetles will hide there during the day. Some people have reported finding as many as 300 in a night, then 50 each night, until they find few or none. New beetles will fly in daily, so be vigilant. Feeding by adults should end by the end of August. Crush them or put them in a container of soapy water until they succumb. Foliage can also be treated with an appropriate insect control product that will kill them after they feed on the leaves, Read and follow label instructions carefully for any control products if they are needed.

Cicada killer holding a Cicada
Photo by Pamm Cooper

Cicada killers are rather mild-mannered (like Clark Kent) burrowing wasps that can cause alarm when they appear in the summer months. These wasps are very large, and females have the potential to sting, but have no aggressive nest-guarding instincts as do most other wasps or bees. What they have is size, and so become easily feared, especially when they burrow along sidewalks or other sandy areas close to pool, gardens and houses.

Female cicada killers burrow a rather rectangular tunnel deep into soft soils into which they will eventually drag a cicada they have paralyzed. They lay one egg on the victim and the larva will feed on the carcass and pupate over the winter. They may be a chronic problem in areas of sandy soils and can be discouraged by disrupting tunneling activity by drenching areas where they are actively tunneling with water. They do not like moist soils, so this may be the only control method needed. Digging may disrupt root systems of plants if the tunnels are made at the base of plants, and watering the plants affected in this way may settle the soil back around the roots. Use of any pesticide would only be effective if wasps are still going in and out of tunnels and should be used only if necessary.

The final pest we will cover are aphids. These piercing-sucking feeding type insects are small, but they can occur, seemingly overnight, in large numbers on plants. Aphids prefer newer growth like upper stems but are not so fussy later in the year when they feed on flower buds, old and new leaves and flower stems. Later in the summer some species may cover older stems right down to the ground. This is especially a problem on common and swamp milkweeds. Aphid feeding can cause wilting of plant parts above where heavy feeding occurs. Leaves can be mottled, then become distorted before turning brown.

Red aphids on a stem
Photo by Pamm Cooper

Control of aphids relies on paying attention every day. Aphid females can give birth to live young during the summer, often fifty or more new aphids appear from each female per day. This is why control seems effective, then before you can say “my plants look really good now”, there are scads of aphids back where they were before. Aphids in high numbers, especially on sturdy stems, can be crushed by hand, sprayed with a suffocating type product like insecticidal soap, or knocked off by a strong jet of water. Keep in mind that the reproductive females have wings, and they will take flight at the first sign of trouble. That is why they can persist on plants.

If aphids are a serious issue on plants, with no control measures apparently working, consider removing the affected plants and adding plants you know they so far have shunned as a food source. It may be a painful but necessary step.

Be alert to what is happening in your own backyard, for it is certain something, good or bad, is going on. The sooner you discover the bad, the better. Know that: “On every stem, on every leaf, and at the root of everything that grew, was a professional specialist in the shape of grub, caterpillar, aphis, or other expert, whose business it was to devour that particular part. “~Oliver Wendell Holmes

For questions about garden pests or any other gardening questions, feel free to contact us, toll-free, at the UConn Home & Garden Education Center at (877) 486-6271, visit our website at www.homegarden.cahnr.uconn.edu

Coleus: A Victorian Dream

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By Abigayle Ward, UConn Dept. of Plant Science & LA Graduate Student

Red coleus in the middle of a flower garden
A bed of red coleus surrounded by magenta celosias, and baby pink and purple petunias, complete with a walking path dividing the bed in two. This circular bed is located at the end of Mansfield Road within the University of Connecticut Storrs campus.

Seen anywhere from great-grandma’s ornamental garden to your neighbor’s hanging basket, coleus are the colorful, velvet-textured leafy cousins of oregano and deadnettle. Native to tropical regions of Africa, Asia, and Oceania, it is thought that Dutch botanists introduced the fascinating foliage to Victorian England in the mid 1800s. Coleus were readily welcomed into homes as parlor plants and into ornamental gardens. They were especially coveted in so-called “carpet bedding” gardens, where bedding plants of equal height are used to create colorful designs such that they appear like “carpets” when viewed from above. Other than coleus, the Victorians enjoyed using colorful flowers such as petunias, asters, and zinnias as carpet bedding. Carpet bedding is still popular today; we have at least one such garden featuring coleus and petunias on display at the University of Connecticut Storrs campus. To design a carpet bedding garden, try combining simple shapes and lines to make symmetric, harmonious patterns. Use green vegetation, such as sedums, or even a green cultivar of coleus, to contrast with the bright colors of flowers and the mulch or soil below.

For those of us lacking yard space comparable to an English country house, a large carpet bed garden might be impractical. Instead, coleus can be planted alongside other flowers for a splash of color in a flower bed against a house or fence. Coleus are the perfect complement to the colorful clapboard siding characteristic of houses in New England – draw attention to the colors of both by putting reds with greens and yellows with purples. If coleus are planted directly into the ground, slugs are one major pest to look out for. In particularly wet summers, such as those in recent years, slug populations can devour entire coleus plants.

To avoid slugs, container gardens may be a wise option. Sitting above the ground and out of field soil, slugs will have more difficulty reaching the tasty, tender leaves. For those with outdoor space around their apartments, container gardens are also generally a renter-friendly option. Coleus grow well in window boxes and other small containers, and they can help add a warm, friendly atmosphere to the entrance of any home. Most cultivars of coleus available on the market today are tolerant of both shaded and sunny conditions, and thus are well-suited to either covered or open porches. In containers, the main pests to look for are thrips, mealybugs, and aphids. These three pests can cause discoloration in leaves, such as silvery/gold, yellow, or black spots. Outside where predators of these pests thrive, infestations should not progress to the point of killing entire plants, but affected foliage may be unsightly. While systemic insecticides may help keep these types of pests off coleus, they also can kill bees. Avoid applying systemic insecticides to coleus outdoors whenever possible. Try moderately forceful sprays with water instead, insecticidal soap or other least toxic controls.

The Victorians also kept coleus as houseplants, and so can you. In plant hardiness zones 6a-7b in Connecticut, coleus are very tender annuals. They will grow prolifically when temperatures are above 60°F, and will experience cold injury if temperatures fall below 50°F. When temperatures plunge below 40-50°F and overnight frost becomes a possibility, leaves will start to blacken and die. At the end of the growing season before the first frost, consider planting stem cuttings in pots and bringing them indoors for colorful, year-round foliage. Coleus as houseplants will do best in north-facing or east-facing windows. Avoid placing them in windows where they experience too much direct sunlight for too long during the day. If windows are unavailable, coleus also grow decently under grow lights.

No matter where they are grown, the main attraction of coleus is its brilliant foliage. Plants grown in containers may benefit from occasional nitrogen additions to keep them growing all season long. Like others in the mint family, coleus grow flower spikes when stressed or when the plant is near the end of its life cycle. While the flowers on the spikes are not very attractive from an aesthetic standpoint, bees, hummingbirds, and other pollinators flock to them. While the spikes can be pruned off if they appear too early in the growing season to encourage further vegetative growth, consider leaving the late-season spikes on, so that bees can collect nectar to sustain their hives over the winter.

While the selection of coleus cultivars were limited in Victorian England, decades of horticultural breeding efforts have given us access to over 1,000 varieties today, including sun-tolerant cultivars, with endless colors, leaf shapes, sizes, and growth habits. Consider adding this versatile Victorian dream to your home garden for splashes of colorful summer foliage.

If you have questions on coleus or on other gardening topics, feel free to contact us, toll-free, at the UConn Home & Garden Education Center at (877) 486-6271, visit our website at www.homegarden.cahnr.uconn.edu or contact your local Cooperative Extension center.