Perennials

Put in the Work Now for Lasting Garden Beauty 

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By Heather Zidack, UConn Home & Garden Education Center 

If you’re planning to do some landscape renovations this summer, you will often hear the suggestion of doing certain tasks “until the plant is established.” If you’ve heard this phrase and wondered what the pros mean, you’re not alone. It’s crucial to understand that the first year of growth is one of the most critical to ensure the success of trees, shrubs and perennials in the landscape.  

The “establishment period” is when a newly transplanted plant pushes roots beyond the original root ball to anchor itself into the surrounding soil and adapt to its new environment. Establishment happens in as little as 2-4 weeks for your veggie starts and other annuals. However, if you are installing woody ornamentals or perennials, it is recommended to provide support for their first year in the landscape. Some species, especially fruiting plants may need longer attention to ensure establishment and landscape success. 

Keeping the plants properly hydrated is going to be your first line of defense in preventing transplant shock. Using sprinkler systems for supplemental water can be problematic for trees, shrubs and perennials. These systems, especially those designed for lawns, maintain moisture in the top 1-2 inches of soil. Our non-turf plants need much more.  Providing adequate water will help new plants acclimate by providing sufficient hydration, but it will also encourage the root system to expand. Roots pull moisture and nutrients from the soil but also act as an anchor to keep the plants upright. Keeping only the top few inches of soil moist will encourage roots to stay in that shallow layer instead of expanding deeper into the soil, hindering the development of that anchoring system. Additionally, watering demand tends to be more frequent with shallow root systems, as the first few inches of soil are more susceptible to drying out on sunny days. Lastly, the shallow roots need to compete with established turf for resources at a 1-2-inch depth. 

While in this establishment period, the standard watering recommendation is 1-2 inches per week, depending on the species of plant. An inch of water is equivalent to 0.62 gallons per square foot of garden area. Watering the plant at this rate encourages it to stretch its roots downward into the soil.  With deeper roots, plants can find moisture even during times of temporary drought deep below ground. This is a huge contribution to drought tolerance, as opposed to the common belief that the plant will just “live longer without water.”  

If the forecast does not predict an inch of rain within the week, gardeners should be out checking the soil for moisture a few inches down and providing supplemental water if necessary. Always check the soil before watering, especially if you are new to gardening. Squeeze the soil in your hand. If the soil particles stick together easily, it is likely that there is enough moisture. If soil clumps fall apart between your fingers or the texture is dusty, the soil is too dry and more water is needed. If you can squeeze water out of the soil like a sponge, there is too much moisture, and you should come back and check in a day or two. Overwatering can lead to root rot and other diseases and finding the balance is a fine-tuned skill developed over time.  

Monitor your new plantings for the first year and watch for signs of transplant shock, pests and disease so that you can adjust quickly and keep your plants healthy during this time. While transplant shock is a normal response to being planted in a new location, the symptoms can be startling to gardeners.  Remember that the UConn Home & Garden Education Center is here to help you determine if you are looking at transplant shock, disease, or possible pest damage. It’s easier to catch and treat issues earlier than it is to react at the end of the season. If you’re vigilant, we can help you find your way to solutions much more quickly! 

Staking should only be done as a temporary measure for young trees where the environment or the species of tree requires extra support. In most cases, trees should be perfectly capable of supporting themselves. Exposure to the elements, like the occasional strong breeze, can help to strengthen them as they adjust. However, temporary staking can help take some of the stress off the young trees if they are establishing in harsher environments. While there are many situations that may be appropriate, consider staking newly planted trees when they are in open areas, have high wind exposure, or are in an area that risks mechanical or physical damage. Staking may also be appropriate if the root ball is significantly smaller in relation to the tree’s size, or if the tree has a top-heavy canopy. 

Once your plants are well anchored into your landscape, they will be able to find water and nutrients on their own while standing tall in the face of our New England climate. Putting in the attention and care to help plants establish in their first year or two in the landscape will reward you with many years of enjoyment to come.  

The UConn Home & Garden Education Center supports UConn Extension’s mission by providing answers you can trust with research-based information and resources. For gardening questions, contact us toll-free at (877) 486-6271, visit our website at homegarden.cahnr.uconn.edu, or reach out to your local UConn Extension center at cahnr.uconn.edu/extension/locations. 

 

 

This article was published in the Hartford Courant June 7, 2025

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.

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

Great Hostabilities

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By Dawn Pettinelli, UConn Home & Garden Education Center

Hostas in a garden
Image by dmp2024

So versatile and ubiquitous are hostas that I have yet to visit a garden that doesn’t have at least one whether left by a previous gardener or selected by the present one. Hostas certainly are workhorses of the garden renowned for their shade tolerance, hardiness and longevity. Plus, few plants have such large variations in size, leaf color and texture. According to the American Hosta Society, there are more than 3000 varieties of hostas covering 45 species including stalwarts of our gardens such as Hosta sieboldiana, H. elegans and H. montana. Now the hostas you purchase are likely complex crosses of multiple species.

Hostas are native to Asia and came to the United States through Europe during the 1800s. Many of us older gardeners referred to them as plantain lilies because their broad leaves resemble a common weed (or herb depending on one’s perspective), plantain. The young leaves are reputedly edible. In fact, the Japanese are said to serve them raw, boiled or fried in tempura. Their palatability probably explains why gardeners around here half-jokingly refer to them as ‘deer candy’.

Hostas are divided by size into 5 groups. Minis are less than 6 inches tall, small range from 7 to 10 inches, medium from 11 to 18, large from 19 to 28, and giants are greater than 28 inches. ‘Gentle Giant’ and ‘Empress Wu’ are close to 4 feet tall with a spread of over 5 feet, if you’re looking for a plant to make a voluminous impression. Keep in mind a plant’s full size when incorporating them into your planting beds.

A notable feature of many hosta cultivars is leaf variegation. On marginally variegated plants the edges of the leaves are light in color, maybe cream or yellow. Medio variegated types have light colored centers with darker edges. There are also 5 groupings for color: green, blue and gold, plus the 2 types of variegation. The gold and variegated cultivars do best in part sun to dappled shade. Placed in a heavily shaded area, they can lose some of their color as only the green parts of the leaves photosynthesize.

Hosta leaves up close with raindrops
Image by dmp2024

Leaf shapes range from thin and smooth to ridged and heart shaped. Sizes range from 2 inches on ‘Mouse Ears’ to over a foot and a half on giant hostas.

While grown mainly for their attractive foliage, hostas do bloom once a year. Most have delicate-looking, tubular flowers in various shades of purple that are attractive to hummingbirds and bees. Fragrant white ‘Royal Standard’ grace part of a patio in my white garden. Their heady scent is especially pronounced on warm summer evenings. ‘Royal Wedding’ is another fragrant, white-flowering variety. Cut down the flower stalks once flowering is finished.

Growing hostas is a breeze. These tough, dependable plants put on their best show when not located in full sun as the large leaves can scorch during periods of hot, sunny weather. That being said, there are some cultivars like ‘Guacamole’ and ‘Paradigm’ which can tolerate full sun with adequate moisture.

An ideal location would be a semi- to fully shaded site in a soil with a pH in the mid 6s and moderate fertility. Hostas are often planted under trees as once established they can tolerate dry shade to some extent. Remember that a tree’s roots will be competing with the hostas and your plants would benefit from extra water and fertilizer.

The two major pests of hostas are slugs and deer. Ragged holes and tears on leaves are a sign of slugs. These soft-bodied creatures feed at night or on cloudy days but slime trails on the leaves or ground may be visible in the morning. Controls include hand-picking, beer traps, diatomaceous earth and slug baits.

Deer can make short work of a bed of hostas. Three strategies are to use repellents, fence them out or plant your hostas amid less appetizing plants. Some have reported less deer damage to blue leaved hostas, maybe because they have a waxy coating. If you’re growing hostas in deer country, you’ll have to figure out what works best for you.

At the end of the season, frost will flatten the leaves of your hostas. Cut them back and remove the foliage from your garden to give both slugs and diseases less places to overwinter. Plants typically need division every few years if they are outgrowing their allotted spaces. Dig up and divide in the spring when the new stems start to poke through the soil but before the leaves unfurl.

If you have questions about growing hostas 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

Keep your Perennials & Annuals Looking Fabulous All Season Long!

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By: Heather Zidack, UConn Home & Garden Education Center

Geraniums and other flowers in a mixed container
Geraniums benefit from regular deadheading. They’re great for beginners because it is easy to tell the difference between new and spent flowers. Photo by H. Zidack

Hanging baskets, planter boxes and perennial gardens that are bursting with color are seldom planted in spring and left untouched until autumn. Deadheading, pruning, trimming and pinching are all techniques that gardeners can use to get that perfect look all season long. While it may be intimidating, this simple task can result in a huge visual impact with only a little effort. Through a series of pruning techniques, we manipulate our perennials and annuals to give us the most beauty we can get out of them in such a short season. It is important to recognize that cutting healthy flowers or shoots can help plants in the long term – no matter how much it may pain us as gardeners to do so.

Deadheading is a widespread practice where gardeners remove flowers that have gone by. One of the first things to become aware of is the difference between a bud and a spent bloom on the plant you are working on. Many gardeners will snip petunia buds, mistaking them for spent flowers. It is important to be vigilant with these cuts. Remember that your plant's goal is to reproduce, and they use flowers to do so. By removing the flowers, you are stopping the plant from producing seed and encouraging it to restart the cycle – meaning more flowers for you!

Some gardeners will select “self-cleaning” varieties of annuals that will shed their flowers without the need to deadhead all summer long. In general, these may not produce seed; therefore can easily restart the process themselves.

The whole practice of deadheading, pinching and trimming herbaceous plants can be boiled down to redirecting the plants energy into different purposes. Where deadheading helps to clean spent flowers, pinching will remove new buds before they bloom. If you want to encourage beautiful single stem cut flowers, for example, you may decide to pinch lateral (side) flower buds to force the plant to put all its energy into a single bloom at the top. Alternatively, pinching the terminal (top) bud will give you many smaller flowers on one stem, creating a fuller appearance.

This same principle applies to pinching shoots of herbaceous plants to make them fill out more. Cutting further down a stem will again remove that terminal bud and cause the plant to focus its energy on new shoots that come from nodes further down the stem. Think of how full your basil plants flush out when you harvest fresh herbs.

Torenia hanging basket
Torenia is considered a self-cleaning annual that is great for shade and is loved by hummingbirds! Photo by H. Zidack

Often, gardeners will notice that in mid to late summer their hanging baskets will start to look “tired.” They may notice prolific flowering on the ends that hang down, but often see that the center of the basket is not as full or may even be dying out. The first thing to check for is to make sure that you are watering them regularly. Because hanging baskets are suspended in the air and uninsulated, they will dry out faster. When you are trimming herbaceous plants for growth you can take one third of the plant volume away at a time, safely. Think about it as playing hair stylist! Cut back one third of the longest growth at the ends, and watch new growth come from the roots. It may also help your hanging baskets to remove any branches that have been shaded or dried out in the interest of “lightening” the growth that is hanging down.  Again, you may lose flowers for a week or two – but the result down the road will be beautiful!

For perennial gardens, June is a wonderful time to do some pruning as well. Cutting back early flowering perennials can encourage a second flush of flowering in some species. This works exceptionally well for plants like Salvia, Nepeta, and Lavender. Deadheading throughout the season will help plants like roses and Echinacea continuously flower. And pinching can help perennial mums form their shape for the fall.

Summer is a stressful time for plants! Disease, pests, and extreme weather can all contribute to a stressful environment. Our New England summers can promote these pressures with high heat and humidity levels. During these times, pay careful attention to your watering habits and adjust, as necessary. In times of drought or excessive heat, plants will use water faster for hydration and cooling, just like we do. Being aware of this can help you know when to check for water and help you be more diligent with your watering practices. Using a balanced, water-soluble fertilizer can also promote plant health and reduce stress in perennials and annuals. This is why it is great to fertilize after pruning and deadheading. If you need more information on trimming, watering, fertilizing, 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

Luscious Lemony Herbs

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By Dawn Pettinelli, UConn Home & Garden Education Center

With summer almost around the corner, many of us are setting in vegetables and herbs in hopes of preparing delectable culinary delights as these plants mature. Aromatic herbs bring amazing flavors and zing to all sorts of savory and sweet concoctions. A citrusy taste complements many dishes and some may not be aware of the wealth of lemon-flavored herbs that are widely available and also easy to grow.

Lemon balm plants up close.
Lemon Balm in the garden. Photo by dmp2024

Long-lived lemon balm has been a staple in my herb garden for years. The attractive heart-shaped, scalloped leaves have a delicate scent when rubbed. Lemon balm is a hardy perennial native to Europe and has long been grown for its culinary and medicinal purposes. Fresh or dried leaves can be made into a calming tea that reputedly reduces anxiety. They can also be used in savory chicken dishes, to make pesto and even in baked goods. The lemon balm I grow is the species and it produces flowers that, like many members of the mint family, are loved by bees. A dilemma ensues as to whether to leave the blossoms for the pollinators and deal with the copious seedlings that pop up the following year, or cut the plant back to encourage more leaf production. Also, once lemon balm flowers, the leaves take on an unpleasant ‘soapy’ taste. Cultivars such as ‘Compacta’ are sterile, so no seeds are produced.

As long as it is grown in a well-drained soil, lemon thyme is another long-lived herb. Growing just 4 to 6 inches tall, it’s an attractive plant in the herb garden, as an edging plant or even as a front border plant in perennial gardens. There are green, golden, and variegated leaved cultivars. Sprigs of lemon thyme can be dried but I like to use them fresh in chicken or rice dishes. The pinkish flowers usually open in July and are a big pollinator draw. Like many herbs, the best flavor is obtained collected before flowering. Plants respond well to regular trimmings.

Lemon basil is an annual in our climate but easily grown from seed. Like all basils, it does best in a sunny, fertile site with adequate moisture. Plants also do great in containers. Leaves have a fresh lemony scent and taste with some hints of mint and spices. If growing from seed, one might want to try ‘Sweet Dani’, which was a 1998 All America Selection winner. Named cultivars such as ‘Mrs. Burns’ lemon basil usually have larger leaves than the seed grown types. Pinch out flower stalks as they form for better flavor or for a longer and more abundant harvest, cut off the top third of your plants about once a month. This encourages greater branching and leaf production. Lemon basil rice is my favorite way to use fresh leaves.

Lemon grass in a garden bed.
Lemon grass in the garden. Photo by dmp2024

A tender perennial, lemon verbena, is mostly grown as a container plant and overwintered indoors. Plants have an exceptionally strong lemon scent and if happy, grow quite vigorously. They can easily get 3 or 4 feet tall and will grow into a small tree in warmer climates. Lemon verbena is native to South America, so it enjoys full sun and hot weather. Leaves can be used in potpourris, teas, and sweets.

Another tender perennial best grown in a pot is the lemon scented geranium. There are several named cultivars with some, like ‘Mabel Gray’ and ‘Rober’s Lemon Rose’, having a stronger scent. Either buy plants or start from a friend’s cutting. The lovely scented wavy leaves can be placed in the bottom of a cake or loaf pan and then filled with batter and baked, imparting a lovely pattern and slight lemony flavor. They can be used fresh or dried for a variety of culinary uses and are also good in potpourris.

Those enjoying Asian cooking are likely already familiar with the rich flavor of lemon grass. While it is native to India and only hardy to zone 10 to 12, it is a pretty vigorous grower that would do well in either a garden bed or container. Reportedly plants may reach 2 to 3 feet in height by midsummer if kept well-watered. The leaves as well as the bulbous base of

the stem are used in recipes. A few stalks can be removed as needed for cooking. Cut back potted plants to 6 inches before overwintering in a sunny window indoors.

For more information about growing lemon scented herbs 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.