A Brilliant Fall Banquet for Birds, Butterflies, and Bees

It’s that most glorious time of year in Maryland, peak autumn, a time of constant change where every day brings new explosions of color. Beyond leaf peeping along our morning commutes, changes large and small are detectable in exquisite detail, if we only pause to step out in nature to look, listen, and smell the fragrance of the season in the air. 

Right now, migratory birds are coming and going, shrubs are blooming and berrying, bees of all stripes are scrambling for the last drops of nectar as fall flowers fade. With some surprisingly low-cost, low-maintenance strategies, you can begin right away to transform your local landscape into a brilliant fall banquet for birds, bees, and butterflies.


At this time of year, wintering birds are beginning to arrive from the north, while some summer visitors linger to enjoy the bounty of fall. Dark-eyed Juncos (Junco hyemalis) are already returning from their northern breeding grounds. I spotted my first juncos of the season flitting about the raised garden beds on Halloween right outside of the Anne Arundel County Extension office. 

cabbage white butterfly
Cabbage White (Pieris rapae) butterflies were introduced to North America and are common across Maryland. Their larvae are considered to be crop pests. They typically reach the end of their adult life cycles toward late October. Photo: S. Small-Lorenz

On the same day, Cabbage White butterflies were still mobbing blooming New York asters in the brilliant noon sunlight on a day of record-breaking late October heat. The viburnum berries had already been plucked, possibly by the Northern Mockingbird (Mimus polyglottos) singing nearby, and its outermost foliage had turned a deep Cabernet red on a chillier night. I suspect that mockingbird has now staked out the American holly berries ripening nearby, as he seeks to maximize his energy intake before winter sets in.

Northern Mockingbird. Photo: Matt MacGillivray, CC BY 4.0

At Howard County Conservancy the day before, I noticed winterberry shrubs loaded with ripening berries, where another singing mockingbird steadfastly stood guard. Native honeysuckle (Lonicera sempervirens) is flowering and berrying simultaneously, gracing the trellis archway into the native plant garden, and the common witch-hazel (Hamamelis virginiana) is blooming, our only witch-hazel to bloom in the fall. 

Taking cues like this from nature can be an excellent strategy for planning our conservation landscaping for year-round color. Planting native berrying shrubs and evergreens not only extends our color palette, it provides natural sources of food and shelter for songbirds like Gray Catbirds (Dumetella carolinensis), Northern Mockingbirds, Cedar Waxwings (Bombycilla cedrorum), Eastern Bluebirds (Sialia sialis), Yellow-rumped Warblers (Setophaga coronata), Ruby-crowned Kinglets (Corthylio calendula), and thrushes as temperatures cool and extra energy is required to fuel up before, during and after migration. 

Depending on your specific location and site conditions, consider planting Maryland native berrying shrubs to enhance your fall bird banquet. These could include northern bayberry, maple leaf viburnum, red osier dogwood, native honeysuckle, black elderberry, native hollies (American, inkberry, and winterberry), huckleberries, and red chokeberry

Leaving fall seed heads standing into winter also provides resources for a whole array of seed-eating birds like sparrows and finches. Even as flowers begin to wilt and fade, they still provide essential nectar resources to native insects that are beneficial for their pollination and pest control services, not to mention as songbird prey. 

So if you are considering what you can do right now for nature and the environment in your own neighborhood, here are a few low- to no-cost fall strategies to get you started right away:

  1. Map out one or more locations that you would like to dedicate to a native shrub planting area. Make note of conditions (wet/dry, sunny/shady, soil type) so that you can select the right plants for your site when the time comes. It isn’t too late to plant native shrubs in most parts of Maryland, but if you choose to wait for spring, you can still start preparing the bed and browsing for fall-berrying shrubs now (see #5)! If you don’t know your soil type, this is the perfect time to do some home soil analysis. Observe where stormwater flows off of your property, and consider planting a mulched stormwater buffer using arborist wood chips and native plants to absorb rainwater which can both help reduce downstream flooding and improve water quality while beautifying your landscape. 
  1. Pledge to leave the leaves this fall. Raking a thick layer of leaves into your designated shrub planting bed will almost immediately start to create habitat, retain soil moisture, and build rich living soils. I call this “Raking by Design.” Think about this – who rakes the leaves in the forest? Towhees, sparrows, jays, bats, squirrels, deer, and many more wild residents…a reminder that leaf “litter” is an important habitat component for many creatures, and it puts essential nutrients back into the soil as the leaves decompose. If you’re concerned about leaves blowing around, it’s fairly easy to contain whole leaves with low garden border fencing, but it isn’t entirely necessary. Consider designating a portion of your yard a ‘no-rake’ wild zone, where you leave the leaves undisturbed, right where they fall.
leaves piled in a garden with a leave the leaves sign
Leave the leaves for healthy soil and habitat. Photo: S. Small-Lorenz
  1. Leave your native flowers standing well into winter, beyond peak bloom. Birds, bees, and butterflies will benefit from the stems and seed heads well into fall and early winter. 
  1. Use fall prunings, cuttings, logs or stumps to create shelter for overwintering birds, bees, and other wildlife. Recycling your “yard waste” is one of the easiest, low cost ways to start building healthy soil and creating habitat to benefit biodiversity in your local landscape. This can take the form of a brush pile, wood pile (situated well away from your home’s foundation), leaving a natural stump instead of stump-grinding, or building a simple “bug snug” like the one pictured here.
sticks piled into a pyramid to make a bug snug shelter for insects
A “bug snug” made with cut woody stems, seed heads, and leaves will provide a shelter for overwintering insects, stem-nesting bees, and birds. Photo: C. Carignan
  1. Browse options for native berrying shrubs to plant this fall or next spring that would be right for the conditions in your yard. While browsing native plant resources like Alliance for Chesapeake Bay’s Native Plant Center, also make note of whether the shrubs you choose are dioecious or not, meaning that you may need to consider planting female and male plants near one another in order for flowers to be fertilized and berries to form. Finding native plants locally right when you want them can be a bit challenging when getting started, so take some time to familiarize yourself with Maryland native plant material sources via Maryland Native Plant Society’s native plant shopping resources

Which of these low-cost, low-maintenance strategies are you planning to try to enhance your fall living landscape? Which berrying shrubs might you consider adding to your fall banquet? Leave us a comment below, and don’t forget to let us know which wild visitors are enjoying the fall feast in your neighborhood!

By Stacy Small-Lorenz, Agent, Residential Landscape Ecology, University of Maryland Extension. Read more posts by Stacy.

Lilac Rejuvenation by Pruning

Each year, the spring and summer seasons seem to go faster and faster, and 2024 is no exception. If you have a lilac shrub, you can probably still imagine the sweet fragrance and beautiful flowers from a few months ago. I get several questions each year about lilacs, so the blog today is going to answer some of those inquiries! 

A few years ago, we decided to begin excavating for our new garage in late summer, and unfortunately, had to move a lilac shrub. The transplanting was not as high of a priority as it should have been, and the shrub suffered tremendously the following year. We gave it a season to see if it would recover, but ultimately, it was too damaged. At that point, we decided to try rejuvenation pruning and cut everything back to 6” above the soil line in hopes that the shrub would come back and have a better overall shape and appearance. We had nothing to lose as the plant was suffering, not growing, and not flowering. 

A lilac that was transplanted at the wrong time of the year and damaged. Photo: A. Bodkins, UME

Question:  What is rejuvenation pruning?

Answer: Lilac rejuvenation pruning involves cutting the entire woody shrub back to a few inches above the soil surface. This can be done if a shrub is really scraggly or if you want to change its shape entirely. Last summer, my parents had to do a construction project behind their very large, 20+-year-old white lilac, and they had to cut it back to the ground. It seems to be rebounding just fine, though!

University of Nebraska-Lincoln Extension guidance recommends doing rejuvenation pruning in late winter or very early in the spring.

March 8th: First sign of life on the rejuvenation pruning. Photo: A. Bodkins, UME
a lilac bush that was pruned severely now has new green leaves
June 4th: Regrowth progress. Photo: A. Bodkins, UME

Question: My lilac has not bloomed for the last several years. What could be wrong? It used to be beautiful each spring! 

Answer: Lilacs need full sun to bloom. Often in people’s landscapes, as trees mature, lilacs get less sun than they once did, leading shrubs that once produced abundant, full blooms to have limited to no blooms.

Question: Why did my lilac bloom in the fall?

Answer: Environmental stress can cause out of season blooming. Some examples include drought, excessive heat, defoliation from pests, heavy pruning, insects, or diseases. 

Question: What time of year should I prune my lilac?

Answer: Many spring-blooming, woody shrubs will set the flower buds for the next season’s growth in late spring or early summer, so be sure to prune for shaping and maintenance purposes as soon as the shrub is finished blooming for the current growing season.

For more information on lilacs, see the Home and Garden Information Center’s page, Lilac: Identify and Manage Problems — particularly the sections on diseases, insect pests, and heat-tolerant and powdery mildew-resistant varieties. 

Remember, you can always contact your local University of Maryland Extension office or use Ask Extension to get answers to all your gardening questions.

By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland. Read more posts by Ashley.

 

Q&A: Why are lilac leaves brown and curling?

Irregular brown spots and blotches appear on lilac leaves, followed by leaf curling and defoliation in late summer. Photo: UME Ask Extension

Q: My lilacs look like death-warmed-over this time of year. Do you know what’s wrong, and is there anything I can do at this point?

A: Lilacs are sadly not very well-suited to our mid-Atlantic conditions. We’re at the southern edge of their heat tolerance, so while they weren’t among the best flowering shrub choices to begin with, climate change is only going to worsen their prognosis. Several types of leaf-spotting fungi and bacteria, plus general heat stress (which also increases their vulnerability to borers), results in foliage that looks quite beat-up by late summer. Brown spots, crispy leaf edges, and bare stems from premature leaf drop are all typical. You can explore lilac ailments and their management on our lilac diagnostic page.

No fungicide will reverse these symptoms once they appear, and while they might work as a preventative if applied before bud-break (and re-applied repeatedly well into the summer), it’s simpler to just grow something else if a plant is going to be that much of a hassle. This is especially true if the treatments don’t work and the plant still winds up looking horrible. Fungicides also carry the risk of harming other organisms.

For now, you can rake up and dispose of any fallen leaves, though this isn’t a foolproof way of removing a source of infectious spores. Cut down the oldest, thickest stems this winter (they tend not to bloom well at that age anyway) and open up the canopy by selectively removing some stems that contribute to foliage crowding. You can do this thinning after bloom next spring.

For anyone really wanting to grow lilac despite these challenges, try cultivars with above-average disease resistance and heat tolerance. While not immune to problems, they perform much better, even if they don’t look exactly the same or have blooms as large or heavily perfumed. ‘Miss Kim’ is a round, compact-growing cultivar with pale lavender-purple flowers that’s been around for decades. Other varieties are now available with pink or deeper purple blooms, some of which even rebloom a bit, sporadically producing flowers into summer and early autumn, though high heat could still hamper that.

dwarf lilac with lavender flowers
Dwarf lilac species and hybrids handle Maryland conditions much better than the traditional varieties. Some recent introductions will also re-bloom sporadically later in the summer. Photo: M. Talabac

All lilacs, but especially the traditional, classic “French” types, should be planted in a location with great air circulation (so, not up against a fence or wall) so wet leaves dry quickly after rain, dew, or irrigation. Wet foliage is more easily infected by pathogens.

The main perk of growing lilacs is fragrance, so if you want a scented replacement, consider: Winterhazel (Corylopsis), Koreanspice Viburnum (Viburnum carlesii) and its hybrids, Summersweet (Clethra), Seven-son Flower (Heptacodium), Carolina Allspice (Calycanthus), various deciduous Azaleas (Rhododendron viscosum and several others), Mockorange (Philadelphus), and Fragrant Abelia (Abelia mosanensis). Their scent characteristics, flower colors, mature sizes, and preferred growing conditions may differ from lilac, but nothing is going to be an exact substitute. Plus, several of these species will offer the additional bonus of showy autumn foliage or (for the native ones) better wildlife value. These are just some shrub ideas; there are also fragrant perennials and, if you have the room, several fragrant trees.

By Miri Talabac, Horticulturist, University of Maryland Extension Home & Garden Information Center. Miri writes the Garden Q&A for The Baltimore Sun. Read more posts by Miri.

Have a plant or insect question? University of Maryland Extension has answers! Send your questions and photos to Ask Extension.

Q&A: Why do my hollies and other evergreens have brown and pale leaves?

holly with leaves showing sections of brown and pale color
Winterburn symptoms on holly. Photo: David L. Clement, University of Maryland Extension

Q: Several of our evergreens (different kinds) have brown or pale, bleached-looking leaves. Do they have a disease already, and can anything be done? Is it preventable in the future?

A: Most likely it’s winterburn, especially since most infectious diseases won’t cause symptoms this early and seldom impact several unrelated plants to the same degree. Winterburn is an abiotic disorder or injury – abiotic translates to without (a-) life (biotic) – meaning the condition has a non-living cause. Abiotic plant disorders are environmental, and causes include wind, water, temperature, and soil pH. In comparison, biotic factors would include insects, mites, fungi, or bacteria.

No treatment is recommended because the damage has been done, but winterburn is rarely a serious threat to a plant’s long-term health. As new growth resumes, the plant will eventually shed the damaged leaves. If it’s too much of an eyesore, you can selectively trim away the worst of it this month. Causes for winterburn typically involve a combination of cold temperatures, wind, and exposure to sun. Any autumn pruning that results in tender regrowth is priming a plant for winterburn, which is one reason it’s not recommended.

Why are cold-hardy evergreens damaged? Leaves “breathe” through tiny pores on their surface, and this gas exchange also allows water vapor to leave the leaf. Moisture leaves our bodies the same way – picture foggy breath on a cold day. Breezy days, especially in winter’s drier air, speeds-up this evaporation, as can the sun’s weak warmth. Meanwhile, during cold snaps, moisture in the surface layers of soil freezes, which prevents roots from absorbing it. Since the plant cannot replenish all of the moisture it’s losing, the leaf tissue starts to essentially freeze-dry. A thaw won’t reverse the damage because the cells have been injured, just like skin with frostbite. (Unlike our skin though, which can heal to an extent, leaf tissue can’t repair itself.)

Broadleaf evergreens are more vulnerable to winterburn than needled evergreens because the leaf surface area and evaporation potential is so much greater. Younger plants also have greater vulnerability because they are still establishing roots. This is the main reason it’s risky to plant evergreens late in the fall. Cherry laurel, boxwood, holly, rhododendron, camellia, and southern and sweetbay magnolias are common winterburn victims in our area. Plants kept in containers are also susceptible because their roots dry faster and experience more drastic temperature swings than they would in the ground.

The only actions you can take to minimize winterburn risk is to site evergreens out of the brunt of winter winds and to periodically monitor their root zones for moisture, irrigating when dry during a warm spell. Plants overwintering in pots can be sheltered a bit near a wall or windbreak, but don’t bring them inside as the interruption of dormancy may detriment their health.

Learn more and see additional photos on the Home & Garden Information Center website: Winter Damage on Landscape Plants.

By Miri Talabac, Horticulturist, University of Maryland Extension Home & Garden Information Center. Miri writes the Garden Q&A for The Baltimore Sun. Read more by Miri.

Have a plant or insect question? The University of Maryland Extension has answers! Send your questions and photos to Ask Extension.

How to plant a container-grown tree – Featured Video

Late-winter through mid-spring and early through mid-fall are the best times to plant woody ornamentals, so this is a good time of year to start planning your process if you are interested in adding shrubs or trees to your landscape this year.

Take a look at this video showing you how to plant your container-grown tree, and for more information, view the HGIC page on the planting process.

Q&A: What’s wrong with my cherry laurel shrubs?

cherry laurel
Cherry Laurel with Leaf Scorch Symptoms and Holes. Photo: University of Maryland Extension / Ask an Expert

Q: My cherry laurels do not look good. There are brown spots and holes on the leaves and white stuff on the trunk. What can I do?

A: First, there is a lot to like about cherry laurels (Prunus laurocerasus). They are popular evergreen screening and foundation plants, deer-resistant, and pretty tough once established. Cherry laurels make their best growth in moist, well-drained soil in full sun to partial shade. They even tolerate full shade.

We receive numerous questions about problems with these shrubs. They can have multiple issues that are attributed to environmental, climate, or site conditions. When the plants are stressed, they weaken and become susceptible to diseases and/or insect pests. It is helpful to be aware of these issues before planting them. Continue reading

The nativar dilemma: The case of my purple ninebark & the leaf beetle

Physocarpus opulifolius 'Diabolo'
Ninebark ‘Diabolo’. Photo by F.D. Richards. Source: Flickr Creative Commons

I thought I was doing the right thing. When I moved into my house 11 years ago, I found a purple barberry shrub (Berberis thunbergii) planted in the backyard by the previous owner. I thought right away, it had to go. I knew Japanese barberries, so commonly planted in landscapes, were escaping (by seed dispersal) into natural woodland areas and creating dense thickets in some areas to the exclusion of native plants. These thickets have been shown to make suitable habitats for Blacklegged Ticks. I didn’t want to contribute to that situation, so I donned my work gloves and set out to remove that prickly beast of a shrub.

In the barberry’s place, I planted a “native” purple-leaf ninebark, Physocarpus opulifolius ‘Diabolo’. It had deep burgundy foliage that made a nice replacement for the burgundy-toned barberry. And, I was selecting a Maryland native plant. I thought it was a perfect choice.

I sang praises about my purple ninebark for years when people asked me for native plant recommendations. It has great spring blooms and beautiful foliage color, and I never had to prune it. And native plants support native insects so I was doing a good thing to help wildlife. I was doing the right thing!

Or so I thought.

It was just this year that I learned from my colleague, native plants specialist Dr. Sara Tangren, that this particular cultivar of the native ninebark was actually detrimental to a specific native insect, the Ninebark Leaf Beetle. My heart just sank when I heard this. I am first and foremost a plant enthusiast, but I also appreciate insects—the essential roles they play in our world as well as their often stunning beauty. And when I looked up the Ninebark Leaf Beetle, I discovered that it is indeed a beauty. And then my heart sunk even further. My purple ‘Diabolo’ ninebark, it turned out, was no good for this native beetle. The alteration in the leaf color – changing the green of the native species to the burgundy of the cultivar – makes it distasteful to the beetle.

Ninebark Beetle
Ninebark beetle. Photo: Pennsylvania Department of Conservation and Natural Resources – Forestry, Bugwood.org

The effects of altered leaf color on plant-feeding insects were noted in a new study published in HortTechnology magazine last month. The authors (Baisden et al.) conducted experiments on several native woody plant cultivars compared to the straight natural species. They looked at whether six altered traits in the cultivated varieties – leaf color, variegation, fall color, growth habit, disease resistance, and fruit size – had any effect on insect feeding, development, and abundance.

In all three experiments they conducted, the researchers found that the cultivars with leaves that were altered from green to red, blue, or purple deterred insect feeding. Results were not consistent for the other cultivar traits they tested.

ninebark leaf variations
Ninebark cultivars, ‘Lady in Red’, ‘Dart’s Gold’, ‘Diabolo’. Photo: Leonora (Ellie) Enking, Flickr Creative Commons

There are a couple of hypotheses as to how leaf color affects insect feeding. Most plant pigments are compounds that do not contribute to the growth of a plant. They may instead provide a defense mechanism. Anthocyanin pigments make a red coloration that may warn insects that the plant has defensive, distasteful chemicals – and they stay away.

The question of whether cultivars of native plants – nativars – have positive or negative effects on native wildlife is an active and ongoing area of research. Results in past studies have been mixed. (For more on this topic, see Mt. Cuba Center research).

Physocarpus opulifolius
The native species of ninebark, Physocarpus opulifolius, has green foliage. Photo: John Ruter, University of Georgia, Bugwood.org

I know how appealing it is to choose plants with special characteristics – the colored foliage, bigger flowers, the more compact form, or general appearance that suits my personal taste. But my choices may not, in some cases, be to the taste of other things in our environment and the things that depend on them for food. It is a dilemma. I do like specific non-native plants (I’ll never give up my dahlias), but I also adore the lilting songs of chickadees in the springtime. Many birds like Carolina chickadees need caterpillars to feed their young and many caterpillars can only feed on wild, native plants. See New Smithsonian Study Links Declines in Suburban Backyard Birds to Presence of Nonnative Plants. I should note that a different study (Craves) found that native birds, including chickadees, were able to find insect food on non-native, invasive Amur honeysuckles. (Which makes the issue even more confusing, right?)

“When we try to pick out anything by itself, we find it hitched to everything else in the Universe.” – John Muir

For an ecologically-minded gardener, it feels complicated to sort this all out and do the right thing. I felt disappointed that my ‘Diabolo’ ninebark was a missed opportunity to support a particular native insect, but, as Dr. Trangren explained to me, it becomes more of a problem when cultivated nativars cross-pollinate with the wild species and change the genetics of the native populations, making them less capable of supporting insects on a broader scale. For this reason, she recommends choosing cultivars that are sterile, if possible.

It was a lesson learned and one that makes me more thoughtful about my plant choices and their broader impacts.

By Christa K. Carignan, Maryland Certified Professional Horticulturist; Coordinator, University of Maryland Extension Home & Garden Information Center.

References:

Craves, Julie A. 2017. Native birds exploit leaf-mining moth larvae using a new North American host, non-native Lonicera maackii. Écoscience, 24:3-4, 81-90.

Baisden, Emily C., Douglas W. Tallamy, Desirée L. Narango, and Eileen Boyle. 2018. Do cultivars of native plants support insect herbivores? HortTechnology 28(5) 596-606.

Narango, Desirée L., Douglas W. Tallamy, and Peter P. Marra. Desirée. 2018. Nonnative plants reduce population growth of an insectivorous bird. Proceedings of the National Academy of Sciences of the United States of America.

Learn more about native plants on the University of Maryland Extension Home & Garden Information Center website.