Landscape Maintenance

Hyped for Hydrangeas

Nick Goltz, DPM, UConn Home & Garden Education Center, UConn Plant Diagnostic Lab 

When I moved to Connecticut in July of 2021, I remember driving through neighborhoods looking for somewhere I might eventually want to live and being struck by the beautifully-landscaped yards that each home seemed to showcase. I particularly remember being impressed by the tidy hedges of hydrangea, filled with lush globes of blue, pink and purple flowers. Can you think of a flower more emblematic of breezy, long summer days by New England coast than the hydrangea? I’ll wait. 

Hydrangeas are a fascinating group of perennial plants with some unique quirks that make them a fun addition for the home garden. The genus is native to Asia and North America, but the species grown most commonly around the world, Hydrangea macrophylla, is native to Japan and has been bred extensively for hundreds of years, resulting in many cultivars. They are also bred with other species to help select for cold tolerance or inflorescence (flower cluster) shape.  

Hydrangea macrophylla are commonly known as “bigleaf hydrangea”, but may also be called “lacecap” or “mophead” hydrangea, depending on the shape of the cultivar’s inflorescence. While many species of hydrangeas have white flowers, bigleaf hydrangeas are prized for their beautiful inflorescences that act as a natural pH indicator of the soil the plants grow in. The petals of flowers will change depending on how basic or acidic the soil is. Flowers will be blue, indigo, or deep purple in acidic soils with a pH of 5.5 or less. Plants gown in a slightly acidic soil with a pH between 5.5 and 6.5 will have a mix of purple hues. Hydrangeas grown in neutral to basic soils with a pH greater than 6.5 (especially 7 and up) will generally have fuchsia to pink-colored flowers. Many gardeners will amend the soil of their hydrangea beds from year to year to achieve the color that they hope for.  

Many folks know of the color-changing capabilities of hydrangeas, but keep reading for a few tips on how to properly care for them beyond adjusting soil pH. Hydrangeas prefer moist, well-draining soil and a sheltered spot with partial shade. Some cultivars tolerate full sun well, but must be watered consistently to look their best. Hydrangeas do not grow exceptionally large and are considered “low fire risk”, so are a better choice for planting near the home. 

A small hydrangea with both purple and pink blooms
This ‘Summer Crush’ hydrangea near my house will have purple blooms in acidic soils and fuchsia blooms with basic soils. Because both colors are appearing, I’m guessing this soil must have a pH between 5.5 and 6.5!

There’s a reason why coastal New England towns seem to be filled with hydrangeas while interior towns, particularly for our friends in Vermont, western Massachusetts, Maine, and New Hampshire, have fewer. Bigleaf hydrangeas can tolerate cold temperatures, but only to an extent. Depending on the cultivar, bigleaf hydrangeas grow best from zones 6 to 8. Most cultivars will survive zone 5 winters, but might not flower well without protection – harsh winter temperatures, especially when paired with low snow cover, can kill flower buds.  

Flower buds form on old growth for most cultivars of bigleaf hydrangea. Because of this, many folks will accidentally prune away flower buds in winter, resulting in poor flower production come summer. For this reason, it’s important to never prune bigleaf hydrangea in fall, winter, or spring. Only prune away the bare stems from the previous year when you see that no new growth is being produced from them, or in summer when collecting flowers for the vase on your kitchen table!  

 If you find the twiggy winter appearance unsightly and can’t help but prune, if you struggle with deer feeding, or if you live in an area with common late spring frosts, consider planting a “reblooming” bigleaf hydrangea. There are a few cultivars, such as ‘Endless Summer’ and sports, that will produce flower buds on old growth and (usually) a second flush on new growth. Alternatively, you could plant other species of hydrangeas, such as smooth hydrangea (Hydrangea arborescens), or panicle hydrangea (Hydrangea paniculata), which tend to be a little more cold-hardy, or oakleaf hydrangea (Hydrangea quercifolia), if you’re looking for a hydrangea for an area with very hot summers.  

If you have questions about growing hydrangeas, or any other gardening topic, call the UConn Home & Garden Education Center (toll-free) at (877) 486-6271. You can also email us at ladybug@uconn.edu, visit our website, www.homegarden.cahnr.uconn.edu, or visit your local UConn Cooperative Extension center.  

 

This article was published in the Hartford Courant and The Westerly Sun July 5, 2025

Set Your Lawn Free

By Dawn Pettinelli, UConn Home & Garden Education Center

Dandelions growing uncontrolled in a lawn.
Photo by Dawn Pettinelli

For many, the sight of a lush green lawn brings about the desire to cast off one’s shoes and stroll through the sun-warmed grass feeling the soft verdant carpet below. Lawns, or at least grassy areas, are a ubiquitous part of almost every home outside city limits. While admittedly that perfect lawn is a source of curb appeal and homeowner pride, in recent years considerable attention has been given to the ecological and environmental costs of maintaining turf that is the envy of the neighborhood.

Managed turf grass areas, including golf courses and park areas cover about 8 percent (400 square miles) of the land area in Connecticut. That perfect lawn typically requires supplemental irrigation, fertilizer, regular mowing and often pesticide applications. Water could be better used for drinking, other domestic uses and just left in natural systems. Excess nutrients as well as pesticides can be found in ground and surface waters causing both human health as well as ecosystem problems. While some are turning to electric mowers and blowers, gas-powered equipment dependent more on fossil fuels, are most prevalent (at least in my neighborhood) contributing to climate change.

So what is a residential lawn owner to do? The authors of Redesigning the American Lawn were among the first to coin the term “freedom lawn.” So, what is a freedom lawn? Basically, anything that is green is allowed to grow. That would include dandelions, self-heal, violets, bluets, buttercups, clover and wild strawberries to list a few of those so-called “low growing broad-leaved plants”. By my definition, weeds are plants growing in the wrong place, so the plants are weeds no longer when accepted as part of the lawn.

One of the greatest reasons for encouraging a variety of plants to inhabit turf areas is that the world is facing a critical loss of biodiversity. There are significant declines in beneficial insect, native plant and bird populations, along with other living organisms. While that lush green lawn offers aesthetic pleasure to some, it does little to provide habitat or food for creatures other than problematic ones like grubs or chinch bugs.

A mixed grass- herbaceous plant lawn will contain flowering plants for pollinators and other beneficials. Various plant species have varying root systems. Some have deep taproots that break up compacted soil and bring up minerals. Others have more fibrous root systems that are continuously turning over added organic matter to the soil. A variety of plants along with their root exudates and associated microbes can help aggregate the soil, improving air and water passage. Porosity plus water holding capacity can be increased as well as lessening the potential for topsoil erosion. A healthy plant community usually portends a healthy soil.

Leaning into a freedom or pollinator lawn does not mean digging up one’s entire lawn and reseeding it although that is one option. Two seed mixes that I have seen advertised are Flawn and Fleur de Lawn. Both contain a mixture of fescues, microclover and the latter, some other flowering species. Probably greatest success with these seed mixes would be achieved starting with bare soil.

One can start encouraging biodiversity and pollinator plants by discontinuing the use of herbicides and allowing some flowering plants to move in. Often, they can be mowed before they set seed. When reseeding bare spots, use more drought tolerant fescues or native grasses like little bluestem to reduce the need for irrigation, once established. Higher mowing heights up to 3 or 4 inches will encourage deeper rooting of all plants making them more resilient during periods of drought.

Learn about the benefits of some of the low-growing broad-leaved plants that want to call your lawn home. Clovers add nitrogen to the soil reducing the amount of fertilizer necessary. Violets are host plants for the endangered regal fritillary. Dandelion greens are a great source of vitamins A and C. It is true that many of these plants are not native, but neither are the cool season turf grasses normally found in lawns.

In many yards, keeping part of it in lawn is essential for children’s play and sports activities, pet areas and entertaining. Take a tour of your yard and determine where a lawn makes sense and where it might be more appropriate for woody plants, ornamental beds or even a vegetable garden. Steep slopes or perpetually shaded areas may be best for groundcovers. Areas where water frequently collects after heavy rains might be more suitable for a rain garden.

However small, every effort to encourage biodiversity, provide for our beneficials and improve soil health is a step in the right direction. Rethinking your lawn areas might be a good place to start.

For information on lawns or any other gardening topic, call the UConn Home & Garden Education Center (toll-free) at (877) 486-6271 or email us at ladybug@uconn.edu or visit our website, www.homegarden.cahnr.uconn.edu.

This article was published in the Hartford Courant May 18, 2025

The Challenges of Boxwood: Pests, Diseases, and Alternatives

By Marie Woodward, UConn Home & Garden Education Center

Boxwood, a classic choice for formal gardens and hedges, has faced increasing threats in recent years. As gardeners grapple with these challenges, it is crucial to understand the issues at hand and explore alternative plants for our landscapes.

Boxwood Blight is an aggressive fungal disease that affects various Boxwood species and causes rapid defoliation and potential plant death. First identified in the United Kingdom in the mid-1990s, this disease has since spread across North America. Early symptoms include stem cankers, sunken lesions, and eventual dieback. To mitigate the risk of Boxwood Blight, choose resistant cultivars, practice good garden hygiene, and monitor your plants for early signs of infection.

The Box Tree Moth is an invasive pest native to Asia that feeds on Boxwood plants. Since its arrival in North America, this moth has wreaked havoc on Boxwood populations, leading to defoliation and plant stress. Symptoms of infestation include see-through plants, "stick shrubs," and stem cankers. Regular monitoring and integrated pest management strategies are essential for controlling this destructive insect.

As Boxwood plants continue to face challenges from pests and diseases, it is wise to consider alternative options for our gardens. Ilex crenata (Japanese Holly) is a versatile, broadleaf evergreen that can be shaped into hedges or topiaries. Its small, glossy leaves provide a neat appearance, and its adaptability to various soil types and sun exposure makes it a low-maintenance choice.

Row of Gem Box Ilex shrubs for sale
Gem Box Ilex is one of many fantastic substitutes for Boxwood shrubs. Photo by H. Zidack

Euonymus japonicus (Japanese Euonymus), an evergreen shrub with small, glossy leaves and tolerance for a range of growing conditions is another possible substitution. Its compact growth habit and easy maintenance make it an excellent choice for hedges or screens.

Ilex glabra (Inkberry), is a slow-growing evergreen native to North America, featuring dark green leaves and red berries in the fall. Its low, spreading habit makes it ideal for low hedges or mass plantings.

Privets (Ligustrum), are fast-growing, low-maintenance evergreen shrubs with small, glossy leaves. They can be used for hedges, screens, or as stand-alone specimens. However, keep in mind that three cultivars, border privet, (Ligustrum obtusifolium Sieb. & Zucc), California privet, (Ligustrum ovalifolium Hassk.) and European privet (Ligustrum vulgare L.) are listed on UConn’s invasive plant databaseIf you decide to plant privets, look for seedless cultivars such as Golden Ticket privet (Ligustrum x vicaryi "KCLX1") at your local nursery.  

The Boxwood Blight and Box Tree Moth present ongoing challenges for gardeners and landscapers. By understanding these threats and adopting appropriate management strategies, we can mitigate the damage they cause. Additionally, exploring alternative plants can help create more resilient and sustainable gardens in the face of these challenges. With careful planning and thoughtful plant selection, our landscapes can continue to thrive in the face of adversity.

The UConn Home & Garden Education Center supports UConn Extension’s mission by providing answers you can trust with research-based information and resources. For questions about your boxwoods or other 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 Feb. 22, 2025
It was been updated from its original publishing on Feb. 27, 2025