Trees & shrubs for pollinators

For some reason, I feel that every time I think about what to plant for pollinators, the list of plants that comes to me is one full of herbaceous ones… however, it is odd that this is the case, because it’s not like our region lacks larger plants (e.g., trees, large shrubs) that are both fully able to support pollinators while also supporting other biodiversity and even contributing to flood and rain management! And because if we’re interested in going the large(r)-plant path, we need a bit of planning, in today’s post I would like to present some native shrubs and trees that are great resources for our pollinators. This way, you can start planning where to get them for planting in late winter to early spring.

Why consider trees and shrubs for pollinators?

Large perennial plants such as trees and shrubs have many characteristics that make them very attractive to any pollinator-friendly person in our region. Indeed, while there are many of these plants that act as wonderful food resources for many pollinators (both adult and larval stages), these larger plants represent long(er)-term and abundant resources that can serve different aspects of our ecosystem: they provide shelter and food for birds, they can assist in managing stormwater runoff, retain soil, reduce surface temperatures by their shading abilities, and provide structural complexity to our landscapes. Trees especially are a key component of creating climate-resilient landscapes. In fact, one of Maryland’s climate change mitigation goals is to grow 5 million more trees by 2031!

Planting trees is not necessarily expensive

From a financial perspective, although these plants may be costlier to obtain than the smaller herbaceous ones, there is a multitude of incentives, state vouchers, and programs that strongly reduce or sometimes completely cover the costs of obtaining them. In Maryland, for example, the state provides incentives through the Maryland Department of Natural Resources (discounts to be used at nurseries; all details here), the PG County Rain Check program or the TreeMontgomery program, city incentives, and free tree plantings (e.g., see College Park’s here). In all of these programs, a lot of trees native to our region are covered. If you would like to participate in any of these programs, make sure to check the specific tree lists covered by each (also, see this list of recommended native trees for the state of Maryland). Note that these programs I mentioned here are just a few of the many that exist; if you’re interested in this, make sure to check your city, county, and state resources!

What to plant?

I hope by now I have at least made you curious about the idea of choosing trees and shrubs for pollinators. Below, I made a very small selection of a couple of plants that appear in the native lists, and that are great for pollinators. Let’s take a look at them.

Tulip tree (Liriodendron tulipifera)

Tulip trees are a great native plant that can serve as a great pollinator resource. This tree is in the same family as Magnolia trees. It can reach a large size and it displays stunning yellow and orange flowers. This tree grows fast and is large (considered the tallest native tree in the eastern USA, along with sweetgums), so it can be a good choice for large spaces where a canopy is wanted relatively quickly. The flowers produce a lot of nectar, which attracts a massive number of pollinators. This makes it kind of fun to stand under the tree on warmer days during the blooming time: the buzzing coming from the tree is pretty impressive. Here are some more details on the conditions preferred by this tree.

the yellow and orange flower of a tulip tree
Tulip trees are among the tallest trees in the eastern USA and have wonderful resources for pollinators that they carry in their stunning flowers. Photo: W. Cutler CC.

American linden or basswood (Tilia Americana)

This tree can reach relatively large sizes, and when it grows to full size it has a very rounded canopy. I personally love this tree, because of the fact that I feel it’s a “social” tree: one can sit with friends under its shade on hot summer days, and just enjoy the life it hosts and the cool breeze it forms under it. Once the season is coming to an end, this tree’s leaves turn a lovely yellow. The flowers of this tree are small and not very colorful, but they are extremely fragrant and full of nectar, which makes them a great magnet for pollinators. You can learn more about the requirements of this tree at Virginia Tech Dendrology.

white flowers blooming on American linden tree
The American linden has discrete flowers that are very attractive to pollinators. Photo: A. Zharkikh CC.

Hawthorns (Crataegus phaenopyrum and C. viridis)

These are mid-size trees that also sustain a variety of fauna through their flowers, fruits, and bird nest-friendly thorny branches. Their flowers are white, have a typical Rose-family structure (like those of cherry trees), and are attractive to bees, syrphids, butterflies, and hummingbirds. Besides being great for fauna, the two species do well in urban environments, because they both tolerate a wide variety of conditions. Here at pollenlibrary.com and on the Lady Bird Johnson Wildlife Center website you can learn more about each of these species.

White flowers of a hawthorn tree in bloom
Hawthorns have lovely white flower clusters. Photo: F. D. Richards CC.

Fringe tree (Chionanthus virginicus)

This small tree/tall shrub is a great addition to green spaces, and is ideal for hedgerows or just as a stand-alone plant. I am always surprised by the super cool shape of the flowers of this plant, which have very elongated petals that create long white fringes. These flowers attract bees and other pollinators, which come to collect some of the nectar that is produced. This plant is usually dioecious, meaning that one individual plant harbors either male or female flowers, but rarely both. This plant is ideal for areas that receive a lot of sun, because it is under those conditions that it will do best (although it can do fine in less-sunny areas as well). You can learn more about this plant by visiting this website.

white flowers of the fringe tree
The whimsical flowers of fringe trees are not just attractive to us, but also to many pollinators! Photo: 阿橋 HQ CC.

Serviceberry (Amelanchier laevis)

Although all of them can provide very good resources for pollinators, I picked this one to showcase because this species grows relatively fast and does not get too large. This is indeed a larger shrub that has beautiful white flowers, and later on, delicious small berries. Because of all this good stuff, the flowers are visited by many insects, and the fruits are favorites of birds (so you’ll have to win over them if you want to get at the fruits! 😉 ). Here and on the University of Maryland Extension website, you can learn a bit more about this cool plant.

Serviceberries make everybody happy: pollinators in the spring with their flowers, and birds and humans in the summer with their berries! Photo: Henna K. CC.

By Anahí Espíndola, Assistant Professor, Department of Entomology, University of Maryland, College Park. See more posts by Anahí.

Anahí also writes an Extension Blog in Spanish! Check it out here, 
extensionesp.umd.edu, and please share and spread the word to your Spanish-speaking friends and colleagues in Maryland. ¡Bienvenidos a Extensión en Español!

Bats!: The Garden Thyme Podcast

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It’s Spooky Season! In this month’s episode, we sit down with Leslie Sturges of the Bat Conservation & Rescue of Virginia to talk about bats. We chat about how much we love bats and why you should also. She tells us all about the types of bat you can find in Maryland (9:53), Whitenose syndrome (17:03), how bats rear their young (23:24), and echolocation (25:50). We also put some of the vampire and other bat myths to rest (40:30). 

We also have our: 

  • Native Plant of the Month – American Persimmon (51:15)
  • Bug of the Month – Twisted winged parasites (45:01) 
  • Garden Tips of the Month (58:25)

The Garden Thyme Podcast is brought to you by the University of Maryland Extension. Hosts are Mikaela Boley- Senior Agent Associate (Talbot County) for Horticulture, Rachel Rhodes- Agent Associate for Horticulture (Queen Anne’s County), and Emily Zobel-Senior Agent Associate for Agriculture (Dorchester County).

Theme Song: By Jason Inc

Goldenrods & asters: Important fall flowers for pollinators

With the fall very clearly upon us, we tend to think more about falling leaves than flowers. Indeed, the big flower boom is ending, with all early-season flowers well past flowering. However, fall is a very important season for many pollinators, which still require food and shelter in preparation for the winter. In this blog, I would like to take a little bit of time to go over the importance of fall resources for pollinators, and what you can do to make sure they are available in your green spaces.

Why is fall special in nature?

The end of summer/fall is a special time for many organisms in our temperate regions. This is usually the last chance these organisms have to gather energy and resources to get ready for the winter. In the case of pollinators that are active during this period, the fall is key for collecting sufficient pollen (=food) for their nests, and for finding appropriate overwintering spaces for the adults and/or the offspring (take a look at this post to learn more about this), all of which will impact survival until the following year/season. If we want to help these pollinators, making sure that these resources are available is the best we can do!

Providing food for pollinators in the fall

Several native plants in our area flower in the fall and act as wonderful resources of pollen and nectar (and more!) for our late-summer/fall pollinators. These plants are easy to grow and once established provide abundant (nutritional) resources for our local insects.

Goldenrods

This group (Solidago spp.) consists of many species which flower in the late summer/fall. These plants are perennials that will create patches once established in an area. For this reason, they are easy to grow, although for this very same reason may usually require a bit of containment, since otherwise, they will easily spread everywhere. If the latter is a problem, plants can be grown in pots, where the containment issue is more easily resolved.

These plants support a large community of many different types of bees (many of which are specialists that can use only specific types of pollen and can be rare), as well as butterflies, flies, and wasps. In fact, more than any other herbaceous plant studied by Fowler/Droege, goldenrod (species in the genus Solidago) supported the most specialist bees (39 species). Importantly, because these plants create tall hollow stems, they can also act as nesting resources for stem-nesting bees. This way, these plants are great fall resources for many of our pollinators.

flowering goldenrod mixed with other asteraceae flowers
Goldenrods develop numerous flowers that provide support to a very large number and diversity of pollinators. In this picture, goldenrods stand out of a background of other yellow Asteraceae in a home garden. Photo: A. Espíndola

Two easy-to-grow species that one can find in several native nurseries are the tall goldenrod (Solidago altissima) and Canada goldenrod (Solidago canadensis). Both species have long stems that end with many yellow inflorescences. Both of them flower in the late summer and fall and can be easily grown in green spaces, especially drier sites that are exposed to the sun. As said before, although these plants are great pollinator magnets and resources, they tend to spread readily, so, unless that is wanted, they require some control once they start spreading in an area.

Asters

Asters are another group of plants native to our region that acts as a great pollinator resource in the fall. These plants are also perennials and can be small or become shrub-like, depending on the species. Unlike the goldenrods we were talking about just above, these plants tend to display a larger variety of floral coloration, with flowers going from white, to pink, and purple, depending on the species. Like goldenrods, these plants provide both food and nesting sites to many pollinators. Their flowers attract a very large variety of pollinators (bees, butterflies, flies, beetles, wasps) during a time when there is little else to feed on. The flowers of these plants are also known to support specialist and often rare bees, which depend strongly on its pollen for survival, as well as many butterflies, including Monarchs. Their stems are also great sites for stem-nesting bees. Finally, their leaves support the larvae of many local butterflies.

purple flowers of new england aster and a monarch butterfly
New England asters can be obtained from native plant nurseries and are able to support a very large diversity of pollinators, including rare and specialist bees, as well as adults and larvae of many butterflies. In this picture, we can see a Monarch adult feeding on the characteristic purple/blue flowers. Photo: Glenn Marsh

A lovely species that can be grown in our green spaces and provides hundreds of blue/purple flowers is the New England aster (Symphyotrichum novae-angliae). This perennial herbaceous plant can be obtained from nurseries and will grow three to six feet tall in the summer (but it can be cut back in mid-summer if you want to keep it shorter). The plant requires at least some sun and does well in a variety of soils we find in Maryland. I love watching the lovely cute flowers, and all the activity they attract. This is really one of my personal fall garden highlights!

By Anahí Espíndola, Assistant Professor, Department of Entomology, University of Maryland, College Park. See more posts by Anahí.

Anahí also writes an Extension Blog in Spanish! Check it out here, 
extensionesp.umd.edu, and please share and spread the word to your Spanish-speaking friends and colleagues in Maryland. ¡Bienvenidos a Extensión en Español!

How to adapt your garden to climate change

The news is filled with references to global warming and climate change. In fact, 99% of scientists agree that climate change is real with negative impacts on the environment, weather, human health, and agriculture. In Maryland, climate change is already causing higher average temperatures, more drought, longer heat waves, more intense storms, and flooding. 

So what can we do as gardeners to help the cause and help our gardens adapt to these changes?

Adopt sustainable practices. Environmentally smart practices build climate-resilient gardens and can slow future warming by reducing emissions and boosting carbon in soil and plants. Here are a few ways to get started:

Plant more trees

Trees filter air and water and are carbon sinks, capturing and storing carbon dioxide, a key greenhouse gas. When placed well, trees can save up to 30 percent on heating and cooling costs.  

  • Plant deciduous trees on the west, east or southwest side of your home to block summer sun then let it in to warm your home in winter. Site evergreens to the northwest to buffer winter winds. 
  • Lean toward native trees. They’re well-adapted and need less water and fertilizer, the manufacture of which can contribute to greenhouse gases.  

Add or nurture native plants

Don’t stop with trees. Native shrubs, perennials, grasses, and groundcovers also help build a climate-resilient landscape. Native plants, once established, require less water and fertilizer, help store carbon, and reduce soil erosion. Since they co-evolved, native plants best support native pollinators and beneficial insects which provide chemical-free pest control. 

HGIC Website: Native Plants and Climate Change

Keep it diverse

Plant diversity also boosts resistance to pests and disease, so add many different types of plants to your gardens. Yes, more is better. 

Save the soil

Washington County Master Gardener Gary Stallings turns compost, a tool in building soil health and climate resilience

Great gardens grow from the ground up. So protect and improve your soil which stores massive amounts of carbon as carbon dioxide and organic matter.  

  • Keep soil covered since bare soil invites problems. Soil covered with plants, mulch, or cover crops best stores carbon, resists erosion, holds moisture, and has more even temperatures. 
  • Minimize soil disturbance from digging and tilling which speeds up the loss of organic matter and disturbs the soil community.  
  • Recycle nutrients by making and using compost. Compost adds organic matter, helps soil hold water and nutrients, and reduces the need for fertilizers. 

HGIC Website: Improve Soil Health for a Climate-Resilient Garden

Water wisely

  • Save water to make your garden more climate-resilient. Use a rain barrel or create a rain garden to capture and filter rainwater.  
  • Water when plants need it, not on a fixed schedule. And plant in the spring or fall when plants need less water to become established.

A few more tips:

  • Limit the emissions that contribute to greenhouse gases. Use gas-powered mowers, trimmers, and other equipment less and opt for alternatives. 
  • Shrink your lawn and replace it with groundcovers and other alternatives which need less water, mowing, herbicides, and fertilizer. When you do fertilize, do it based on a soil test to use only what you need. 
  • Help more by growing some of your own food or supporting local growers to cut down on emissions from long-distance transportation. 

You can make your garden more climate-resilient. Start with a few steps and build on them to help your garden successfully adapt to climate change.   

By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension. This article was previously published by Herald-Mail Media. Read more by Annette.

This article was previously published by Herald-Mail Media.

Maryland gardeners are adapting to climate change

How are Maryland gardeners adapting their gardens and green spaces to climate change? We posed this question to our colleagues in the University of Maryland College of Agriculture and Natural Resources and several of them shared examples of everything from composting and food gardening to planting trees and native plants, installing rain gardens, and more.

Action on climate change is needed on a large scale, and our individual actions at home and in our communities all add up too. Check out our Story Map showcasing the variety of ways Marylanders are adapting their green spaces with climate change and sustainability in mind. Then take our quick poll at the end of the Story Map and let us know: Are you doing climate-resilient gardening?

Screen shot of the climate-resilient gardening story map

View the Story Map

Learn more:

By Christa K. Carignan, Coordinator, Digital Horticulture Education, University of Maryland Extension Home & Garden Information Center. Read more posts by Christa.

Poison ivy management strategy: scorched earth or pick my battles?

Recently, as I was walking my property and spotting some more returning poison ivy here and there and lamenting the existence and stubbornness of this pesky weed, a novel thought (for me) popped into my head: I know poison ivy is a native plant – does this mean it is right to totally eradicate it?

A study showing more CO2 in the atmosphere means we might get stronger, more potent poison ivy in the future with climate change, so it’s probably good to determine a strategy moving forward.

About five years ago, I had made an attempt to clear a space on my property beyond my fence and into a drainage ditch that was hard to reach, but getting overrun with tree-smothering vines, English ivy, and all matter of problematic brush. After several hard hours of pulling, clipping, snipping, and dragging, I declared the job done. In the next few days, poison ivy rash made its appearance up and down both arms, a bit on my legs, and even a few places on my body I must have rubbed. This took weeks to heal, and I resolved to be more careful in the future. I hadn’t even realized poison ivy was back there.

The next year, I wore pants, got better educated on how to spot it, and kept a better eye out for poison ivy while I worked on maintaining the same space. Poison ivy again got me pretty bad on the arms!

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Shade Gardening – The Garden Thyme Podcast

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Hello Listener,

The summer heat is here, and if you are like us, you are taking a break under the shade of a lovely tree. In this episode, we are talking all about shade — why we love it, some tips for gardening in your shady area ( 10:07 ), and a list of native plants ( 16:35 ) that enjoy the shade as much as Mikaela.

We also have our: 

  • Native Plant of the Month – Northern Maidenhair Fern- Adiantum pedatum  at 30:35
  • Bug of the Month – Eastern Beach tiger beetles at  33:50 
  • Garden Tips of the Month at  39:45

  1. If you have any garden-related questions please email us at UMEGardenPodcast@gmail.com
    or look us up on Facebook at https://www.facebook.com/GardenThymePodcast.
  2. For more information about the University of Maryland Extension and these topics, please check out the UME Home and Garden Information Center website at https://extension.umd.edu/hgic.

The Garden Thyme Podcast is a monthly podcast brought to you by the University of Maryland Extension. Hosts are Mikaela Boley- Senior Agent Associate (Talbot County) for Horticulture, Rachel Rhodes- Agent Associate for Horticulture (Queen Anne’s County), and Emily Zobel- Senior Agent Associate for Agriculture (Dorchester County). Theme Song:  By Jason Inc.