How Are Aquatic Plants Pollinated?

When we think about pollination, we tend to only think about terrestrial plants. However, a large number of plants are not and actually live fully or partially in the water. These plants also need to reproduce, and thus need to have their flowers pollinated to produce seed. How do they do it? In today’s post, I will try to give a (short) answer to that question, using some native plants as examples.

You may recall from previous posts, that flowering plants require pollination to be able to produce seeds and thus reproduce. Since we are terrestrial organisms ourselves, we tend to be more aware of other organisms and processes that share that trait with us, and pollination is no exception. However, there are lots of flowering plants that are completely or partially aquatic, and these plants also require pollination to produce seeds. Depending on the specific requirements of the plants in question, some of them may use different strategies for pollination.

Wind pollination

Many aquatic or semi-aquatic plants depend on wind to transfer pollen to the female reproductive structures. Especially under conditions distant from land, using wind as a means of pollen dispersal can be extremely advantageous. In fact, being distant from land tends to reduce the types and number of animals that can visit the flowers of aquatic plants. By depending more heavily on wind, these plants usually display light and abundant pollen that can be readily blown away and potentially deposited on the stigma of the female counterparts. A global evaluation of this indicated that about a third of all aquatic plants in the world are wind-pollinated.

In Maryland, an aquatic plant known to be wind-pollinated are watershields (Brasenia schreberi). This plant has non-showy flowers that display both anthers and stigmas. In order for the plant to promote cross-pollination (i.e., avoid receiving pollen from its own flowers), the flowers of these plants go through a complex blooming process that spans two days. This process involves on the first day the receptivity of the stigma (the female part that receives the pollen) and on the second day the maturation and release of the pollen grains. When the grains mature, they are swept by the wind and can reach stigmas from other flowers that are at that point going through their first flowering maturation step.

Animal pollination

It has been shown that a large number of aquatic plants are at least partially pollinated by insects or other animals. In fact, as is also the case in terrestrial plants, aquatic plants can sometimes use both wind and animals to transfer pollen, increasing the chances of some pollen eventually reaching the stigma. Animal-pollinated aquatic plants are pollinated by a large variety of organisms, but their identity will depend on the specific place where the plant is growing and the ability of the pollinator to reach the plant and even survive in that environment. For example, while large bees may be able to fly further away from land, smaller insects may mostly visit plants that are close to land.

A special case of insect pollination of a Maryland native is that of the arrow arum or tuckahoe (Peltandra virginica). The species belongs to the Araceae family and displays a stunning pollination system. As is often the case in this family of plants (see also the skunk cabbage example we talked about in a previous post), the maturation of the female and male flowers is linked to the production of specific aromas. In the case of the arrow arum, these smells attract small flies, and in particular individuals of Elachiptera formosa. These flies seek the flowers to mate, feed on pollen, and eventually lay eggs on the plant, making this an example of what is called nursery pollination (the plant receives a pollination service in exchange for providing a brood site for the pollinator). By moving along the flower, these tiny flies move pollen from the anthers to the stigmas. Some of this pollen may come from the same plant, but other pollen may come from a different flower already visited by the flies.

Water pollination

Finally, many aquatic plants display flowers that are either completely submerged or floating on the surface of water. These plants usually use water currents to disperse their pollen. As with wind, this dispersal is very inaccurate, which usually leads to the release of a large amount of pollen. These plants have either pollen that floats on water or remains attached to the anthers which float to the stigma.

aquatic plants with tiny white flowers on the surface of water
The American pondweed is one of our native species that uses water as their means of pollen dispersal. Note the very small white flowers that are placed on the surface of water. Photo: C. Fisher

A very common native from Maryland that displays this type of pollination is the pond- or waterweed (Elodea canadensis). This species native to North America displays flowers that have either anthers or pistils, but not both. The flowers with anthers are often displayed over the water, from where they release the pollen, which lands and then travels on its surface. By moving on the surface of the water, the pollen can reach the slightly submerged stigmas of the pistilate (female) flowers, which are held on flowers that float at the very surface of the water. Because such a dispersal can lead to large pollen loss, pollen release in this species is only done when the wind is light and the water current is low. This promotes a more “controlled” dispersal and increases the chances of the pollen effectively reaching the stigmas.

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,, and please share and spread the word to your Spanish-speaking friends and colleagues in Maryland. ¡Bienvenidos a Extensión en Español!

Cicada Killer Wasps Are Scary But Good

a close-up view of a cicada killer wasp showing its light yellow and black striped abdomen
Cicada killer wasps are good pollinators who keep cicadas in check.
Photo: Dawn Dailey O’Brien, Cornell University

It’s big. It’s creepy. It’s the cicada killer wasp and it has some local folks worried. But it’s a good guy. Honest. 

Looking like yellowjackets on steroids, 2-inch-long cicada killer wasps are yellow and black and a bit intimidating. But it’s all a show. 

Unless you’re a cicada, you have no worries. These wasps help control the annual cicadas buzzing in our trees.

In fact, male cicada killer wasps don’t have stingers at all and females aren’t likely to sting unless you step or sit on one.

In addition to their ginormous size, cicada killer wasps worry folks because they do figure eights over lawns, looking like they are Up To No Good.

Nope. Those are just males establishing or defending territory. Boys will be boys. 

The dudes have been hanging out since July, scoping out territory while waiting for the ladies to arrive. Their manly posturing results in often spectacular wing-whirling combat, all bluster and bluff.  

Check out the video of a close encounter with University of Maryland entomologist Mike Raupp’s Bug of the Week feature.

Following a brief romantic interlude, the female cicada killer wasp digs a finger-sized nesting chamber in the ground, leaving telltale piles of excavated soil.

Then she climbs trees in search of the cicadas which she uses to feed her young. 

When she finds a cicada, she stings it to paralyze it, then flies the cicada down to the ground, dragging it to her nest. This is no mean feat since cicadas are much larger than she is. That’s one determined mama.

She stuffs the cicada into her nest, lays an egg on it, and seals the opening. When the egg hatches, the larva will chow down on the cicada which is, unfortunately, still quite alive. Ah, the circle of life.

Well fed, the larva will wrap itself in a case, pupate and stay underground before emerging as an adult next summer. 

Interestingly enough, female cicada killer wasps can choose the sex of their babies. If they give them one cicada as food, they turn out to be boys. Given two cicadas, they become larger females.

A female cicada killer wasp’s work is never done. As soon as she seals one nest, she makes a new one and goes cicada hunting again, helping to keep their population in check.  

See female cicada killer wasps in action in this Bug of the Week profile.

Cicada killer wasps also are good pollinators, moving pollen from plant to plant as they feed on nectar as adults.  

Cicada killer wasps congregate around some petunias.
Photo: John Lefebure

What should you do if you find cicada killer wasps in your yard? Not a thing. Tolerating them is best since they’re only around for a few weeks and are beneficial. Chemical controls are not necessary.

But if you’re bothered by the holes they make in your lawn, wet down the area with a sprinkler.  Cicada killer wasps don’t like to build nests in moist soil.

They also avoid nesting in dense lawns. So their nests are a clue that your lawn may need some beefing up.  

Cicada killer wasps may be big and a little scary looking. But I hope you’ve gained some appreciation for these fascinating insects and enjoy watching them dance over your lawn.  

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.


Insects: Our Most Under-Appreciated Neighbors

Why should I want bugs, insects, and creepy crawlies in my yard or green space?

Insects are an incredibly diverse group of organisms, with 91,000 described species in the United States and likely an equal number yet to be described by scientists. Only an exceedingly small fraction of these species ever have negative impacts on humans as “pests” (<1% of species). Often the overabundance of pest species is due to human agricultural and landscape practice choices. The vast majority of insects in shared spaces with humans like yards and parks are going about their own lives. In addition to being fascinating creatures deserving of habitat in their own right, they also often contribute to unnoticed but very important tasks that help humans, termed “ecosystem services.” The next time you see one of these critters in your yard, consider thanking them rather than smashing them.

What are ecosystem services?

Ecosystem services are benefits that humans gain from the environment. Examples of ecosystem services include water filtration, raw material production, erosion control, and pollination. Some ecosystem services, like the maintenance of atmospheric gasses (e.g. plants remove carbon dioxide and produce oxygen that humans breathe), are noticeable and directly impact our everyday lives. On the other hand, services like decomposition may go unnoticed because they indirectly affect us.  

Insects (and their arthropod relatives like spiders and earthworms) play vital roles in many ecosystem services. This is often due to insects interacting with plants in some way, though insects also provide food for many other animals. Below are some examples of the ecosystem services that insects contribute to.

Water filtration

Filter-feeding insects positively affect water quality because they remove particles of dead organic material. Insects retain many of the nutrients they filter out of the water, thus reducing the likelihood of algal blooms, their associated toxins, and dissolved oxygen “dead zones.” This is crucial because clean water provides habitat for other plants and animals like fish and amphibians. It also means less effort is required to purify water for human use. 

Types of insects that improve water quality:

  • Blackflies, mayflies, stoneflies, and caddisflies (Note: the underlined insect groups are not “true” flies in the taxonomic Order Diptera; they are part of other orders.) 

Other types of organisms that improve water quality:

  • Mussels, crayfish, snails

More information: Why Care About Aquatic Insects


Biocontrol is when natural enemies are used to suppress pests and reduce the amount of damage they cause. Natural enemies are insects that are antagonistic to pest insects. There are three types of natural enemies: predators, parasitoids, and pathogens. Preserving natural enemy populations is crucial to reducing our reliance on pesticides because when natural enemies are active, pest outbreaks are less likely to occur in the first place. Predators need food all year, so they also need alternate prey available in order to prevent pest outbreaks. Pesticides eliminate beneficial insects in addition to pests, so they should be used only as a last resort.

Fun fact: Fireflies spend much of the year as larval predators belowground, feeding on pests like grubs in turfgrass yards. If no prey is available in yards, then there will be no display of adult fireflies in the summer.

Types of insects used for biocontrol:

Other types of organisms used for biocontrol:

  • Fungi, birds, amphibians, reptiles, and mammals

More information: Approaches to the Biological Control of Insect Pests.

Seed dispersal

Seed dispersal is when seeds are moved away from the parent plant. Seeds are moved when insects knock them off while feeding or when insects collect and then move seeds to a new location. Seed dispersal is important because it reduces resource competition between the parent plant and offspring plants. It also makes germination and seedling survival more likely, especially in arid climates. 

Types of insect seed dispersers:

  • Ants (most effective), beetles, wasps, thrips, and some moths

Other types of seed dispersers:

  • Fruit-eating animals (frugivores), such as some monkeys, lizards, and bats
  • Unwitting animal dispersers of sticky seeds like this

More information:

Seed Dispersal – The Australian Museum

The Conservation Physiology of Seed Dispersal

Decomposition & nutrient cycling

Nutrient cycling and decomposition are two important processes that rely on one another. Nutrient cycling is when soil nutrients are taken up by plants, insects eat plants, and then those nutrients are reintroduced into the soil when dead insects and droppings are broken back down into nutrients via decomposition. Decomposer insects help clear dead animals and plants off the ground which would otherwise accumulate everywhere. They also help create soil texture and circulate nutrients back into the soil, which plant populations and productivity depend on.

Types of insect decomposers:

  • Many beetles, springtails, termites, wood cockroaches, and some fly larvae (maggots)

Other types of decomposers:

More information: Decomposers

Supporting food webs

Insects are a main source of protein and nutrition for many animals (and even some plants). They play a crucial role in transferring energy from plants to larger animals that eat insects like spiders, birds, frogs, fish, bats, foxes, opossums, and bears. This wide food base that they provide allows for functioning, stable ecosystems that are resilient to disruptions.

Fun fact: By weight, there are roughly 300 times more insects than humans on Earth.
There are so many animals that eat insects, but here are just a few examples:

  • Terrestrial bird species, in particular, feed their babies almost exclusively with insects, and if there are fewer insects, baby birds are less successful at fledging from nests.
  • Popular fish like salmon, bass, and trout eat insects, especially when they’re young.
  • Grizzly bears will eat tens of thousands of moths a day to prepare for hibernation.


Pollination is the transfer of pollen between flowers, resulting in flower fertilization and seed/fruit production. It is an unintentional consequence of pollinators going from flower to flower to feed themselves. Pollination is crucial for human survival, as 80% of plant-based foods and products rely on animal pollination. According to the USDA, pollinated crops are worth $18 billion in the US alone. Foods requiring pollination include apples, blueberries, chocolate, coffee, grapefruit, peaches, peppermint, sugarcane, tequila, and vanilla. 

Fun fact: beetles were likely the first insect pollinators– starting 200 million years ago!
Types of insect pollinators:

  • Bees, wasps, beetles, flies, ants, butterflies, and moths

Other types of pollinators:

  • Birds and bats

More information:

Pollination Basics

What is Pollination?

Why is Pollination Important?

Pollinated Foods

By Yasmine Helbling, Kelsey McGurrin, and Karin Twardosz Burghardt, from the University of Maryland Department of Entomology, Burghardt Lab

And the Pollinator Prize Goes to… Hoverflies!

We hear a lot about pollinators these days, but most of the attention appears to always go to one group of them: bees. However, the diversity of pollinators expands way beyond this one group of insects, as we discussed in a previous post. In today’s post, I want to bring the spotlight to one of those non-bee pollinators, which I always feel stay in the background of our pollinator discussions and are massively underappreciated, despite their important role in our ecosystems. Come with me to give hoverflies the recognition they deserve.

What are hoverflies?

With over 100 species in Maryland, hoverflies (sometimes also called flower flies, or simply syrphids) are a group of flies that belong to a family of insects called Syrphidae. They are called hoverflies because they are very good fliers, able to quickly change directions or maintain their flying positions in very impressive ways. While their larval stages can have a huge variety of nutritional needs (some of which make them great biological control agents of pests), a very large number of the species are strongly associated with flowers as adults. In fact, the females require nectar and pollen consumption for their ovary development, making them depend strongly on floral resources for reproduction. For this reason, they act as important pollinators of many wild plants and crops, especially in temperate climates. Although not fully recognized by the general public, pollinating hoverflies have been shown to contribute globally to the pollination of over 70% of crops globally and about the same percentage of European wildflowers (few studies have evaluated the latter in North America)! You can learn more about this in this recent publication.

Hoverflies can be recognized by their large eyes, short antennae, and at rest their wings positioned perpendicularly to their body, as seen here in this (likely calligrapher or Toxomerus) hoverfly from Maryland. Photo: A. Espíndola

Ecology and biology of hoverflies

I hope that you’re now starting to get excited about these little creatures. Before you run outside to try to catch a glimpse of them, let me tell you some more about their lives, so you can continue to be amazed at what they do and why I am on a “pollinator recognition” mission for them.

As I was saying before, a vast majority of hoverflies are strongly associated with flowers. This makes them potentially important pollinators, and this is indeed true for many of them. However, there’s another reason why they are so important: their ecology. In fact, hoverflies have migratory or at least long dispersal behavior. This means that they have great potential for long-distance dispersal of pollen, and thus can contribute strongly to the pollination of plants that may be spatially far away from each other. Thinking about pollination and its role in plant reproduction, such long-distance pollen dispersal can be key in the reproduction of isolated plant populations, and even in increasing and maintaining genetic diversity in those populations. All of that tends to positively impact the ability of those plants to maintain their populations, making hoverflies key actors in sustaining the diversity of many wild plant species.

And also, because I really want to make an impression on you 😊, know that when I talk about hoverfly migration, I am talking about migration patterns that can in some cases be equivalent to those of more “famous” insects, such as monarchs. Some studies have shown some hoverfly species migrate thousands of miles, following the seasons. Although this is relatively well-studied in Europe, we know that similar migration patterns also occur in other parts of the globe, including North America. And as a fun fact, in our research group at UMD, we believe that we once observed and sampled a wave of migration of hoverflies right here, while studying pollination interactions in the endangered serpentine grasslands of Maryland.

a fly that looks like a bee with large black eyes

a syrphid fly that looks similar to a bumblebee

a syrphid fly has yellow and black stripes and two wings
Hoverflies often trick us into thinking that they are something they are not. Here we have some great examples of elaborate mimics of bees/bumblebees and wasps. Can you spot the traits that give them away? Top: Bare-eyed bee mimic (Mallota bautias); center: Hairy-eyed bee mimic (Mallota posticata); Bottom: Transverse-banded flower fly (Eristalis transversa). Photos T. Shahan, M. Wills, J. Gallagher. All CC.

How to recognize them?

Perhaps a reason why hoverflies are underrecognized is that many of their species display impressive body mimics of other species, many of which people tend to be afraid of because of their stingers. For example, some of the most common hoverflies in our area display yellow and black stripes, tricking us (and potential predators) into believing they are in fact wasps or bees. This is a strategy that protects them from predation but also requires us to be more attentive when we are trying to find them.

Despite this, there are some simple ways to recognize their trick. Because they are flies, hoverflies have characteristics that differentiate them clearly from other groups of insects, such as wasps. One of the main traits to look for when trying to figure out if we are facing a hoverfly (vs. a wasp, for example), is looking at their wings. Unlike bees and wasps, flies have only one pair of wings, which at rest they usually extend perpendicularly to their body, which makes them look like a plane or a “T”. Wasps and bees, on the other hand, typically don’t do this, and they fold their two pairs of wings flat over their abdomen while they are at rest.

Another way to tell them apart from most other wasps and bees is their heads (this may be also useful when the wing trait is not easy to see). In fact, flies generally have VERY large eyes (just think about any fly costume 😉). Hoverflies are no exception! They also have large eyes that cover a very large part of their heads, as well as very short antennae. On the other hand, bees and wasps, usually have much much longer antennae that extend way beyond their heads.

Ready to go out and find some of them? Remember that you can always check out iNaturalist to help you out with identifications! Good luck!

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,, and please share and spread the word to your Spanish-speaking friends and colleagues in Maryland. ¡Bienvenidos a Extensión en Español!

An Ode to Beebalms, Our Beautiful Biodiversity Magnets

Scarlet beebalm (Monarda didyma). Photo: A. Espíndola

Among the many native plants of North America, there’s one that every summer stuns me with its beauty and its important role in our ecosystems and our lives. In today’s post, I want to share some information about a lovely group of plants local to right here, which can be easily grown in our green spaces, and which one can observe flowering right now: beebalms!

What are beebalms?

Beebalms are a group of plants in the mint family (Lamiaceae) that belong to the genus Monarda. This genus is restricted to North America and includes several species. In Maryland, there are at least four species present, one of which (M. clinopodia, the basil beebalm) is currently listed as requiring conservation actions (listed as Vulnerable). The other three species (M. didyma, M. fistulosa, M. punctata) appear to be relatively common in the region and are easy to grow in our green spaces. All species reach about 2 to 5 feet in height and are great additions to flower beds because of their beauty but also because they act as biodiversity magnets. For example, the genus Monarda has been recognized as supporting at least three rare and specialist bee species in the Eastern USA, and attracting a lot of natural enemies of pests, meaning that providing these floral resources can support the populations of bee species that depend on the pollen of these plants for their nutrition and help us naturally control pests in our green spaces. And last but not least, later in the season their fruits support birds and, if left uncut, their stems offer overwintering spaces for arthropods.

Scarlet beebalm (M. didyma)

This is a perennial species with dark red flowers that bloom during the summer. As for all beebalms, the flower heads are formed by many elongated flowers that harbor abundant nectar. The plant is incredibly attractive to pollinators, acting as a magnet to bees of all sizes, butterflies, and hummingbirds. Besides its great support to pollinators and other arthropods, this species (along with M. fistulosa) has medicinal properties, which have been identified and used since immemorable times by Native Americans. The very name of beebalm is even related to these uses, since the plant can be used to produce poultices that help with skin affections, including bee stings. Preparations of the plant are also traditionally used to help with digestive and respiratory issues. Finally, as for many mint plants, this species is rich in essential oils, which makes it a good one to flavor foods like one would do with oregano and mint. You can learn more about how to grow this species, along with other facts on this USDA information sheet.

a stand of brightly colored red flowers - monarda didyma

Scarlet beebalms display red flower heads that offer abundant nectar to a large variety of vertebrate and invertebrate pollinators. Photos: A. Espíndola, J. Schneid (CC)

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Pollination: The Garden Thyme Podcast

The garden thyme podcast episode on pollination and pollinators

In this month’s episode of The Garden Thyme Podcast, we are excited to celebrate National Pollinator Week ( June 19-25, 2023)! A pollinator is any animal that visits flowering plants and moves pollen from flower to flower, which helps plants reproduce, making fruits and seeds. In North America pollinators include bees, butterflies, moths, flower flies, beetles, and wasps. Worldwide, approximately 1,000 plants grown for food, beverages, fibers, and spices need to be pollinated by animals.

We also have our: 

  • Native Plant of the Month – Beardtongues (Penstemon digitalis and P. hirsutus) ~16:40
  • Bug of the Month – Fig wasps (Agaonidae sp.) ~21:18
  • Garden Tips of the Month – ~30:00

If you have any garden-related questions, please email us at or look us up on Facebook. For more information about these topics, please check out the Home and Garden Information Center.

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

Q&A: Pros and Cons of the No-Mow May Movement

Q: Do you have any information related to the “no mow” movement? We have a very weedy lawn and are considering replacing it with Dutch clover. Is that a good idea? Bad idea? 

A: We do not recommend replacing lawn outright with clover. Clover goes dormant in winter, losing leaves, which leaves the soil surface exposed to weed seed colonization and potential erosion. The clovers used in lawns are also non-native and would not support the majority of our native bees (which are specialists, relying on certain native species for pollen, nectar, or plant oils). Generalist bees can use clover or other blooms but these tend not to be the local bees needing the most support from garden plantings.

If you prefer to augment your existing lawn with clover, consider microclover, which is a dwarf and less-aggressive variety of white clover that cohabitates with turfgrass more cooperatively. While not solving any of the other above issues, at least this is a more suitable choice when using clover in a lawn. Our Lawns and Microclover page provides some pros and cons plus links to a more detailed publication (PDF document) about how to go about creating and maintaining this mix.

a flowery lawn with unmowed grasses
Chanticleer’s flowery lawn interpretation, more of a no-mow-ever than a no-mow May situation, and thus of more benefit to wildlife. Photo: M. Talabac

Opinions among professional horticulturists about “No Mow May” actions are mixed because there are both benefits and drawbacks that it creates. You will probably find both proponents and opponents to this practice in Extension and other science-based web publications and articles. The main benefit of the movement is its ability to get gardeners thinking about their landscaping choices and actions and the impacts of these on the ecosystem. (And that’s a good thing!) That said, most of the flowering lawn weeds that no-mow is supposed to protect are non-native and do not support many of our native bees, and allowing them to set seed only enables them to spread further in places where native plants should ideally be growing instead. 

For gardeners interested in having turf serve double-duty as a “bee lawn” – that is, intentionally planted with seed mixtures containing low-growing flowering plants – the benefits and shortcomings of this approach are similar to those with clover lawn conversions or from reducing mowing for limited periods of time. University of Minnesota research shows that bee lawns do provide benefits for pollinators, including native ones. However, most commercially-available bee lawn mixes contain plants from Europe and/or Asia, and are perhaps not the best nutritionally for Maryland’s specialist bee adults or a resource they will be able to use for their young. Some Maryland native plants that can be incorporated into bee lawns, such as Self-Heal (Prunella vulgaris subspecies lanceolata), are not readily available in seed mixes here, and research on Maryland-native plants for use in bee lawns is not available at this time. Visit UMN’s “Planting and Maintaining a Bee Lawn” web page for more detail.

Our energies and efforts aimed at benefiting insects, birds, and other organisms may be better spent creating native plant gardens alongside of (or in place of) lawns, which will not only serve specialist bees more suitably but also will support a variety of other native wildlife in the process. In any garden setting, including when plant selections are native-focused, using a diversity of plant species has several benefits: it can support a greater diversity of wildlife (including pollinators and beneficial insects that help suppress pests), it adds aesthetic and seasonal interest, and it increases the resiliency of the planting as a whole, because different species won’t have the same degree of vulnerability to any one issue (like drought or flooding) that may arise.

white flowers of fleabane in bloom
 Native common fleabane (Erigeron philadelphicus) blooms in a front yard where a portion of the turfgrass was removed and replaced with little bluestem, switchgrass, and a mixture of flowering perennials. Fleabane supports a variety of native bees, solitary wasps, and other beneficial insects. Photo: C. Carignan

Not mowing lawns regularly also stresses the turf by creating a situation where, when mowing does resume, it’s removing much more of the turf’s leaf mass at one time, causing stress and interfering with its normal growth habit that creates a dense lawn. The “grazing response” that mowing triggers, promoting more low growth that fills-in gaps, won’t be happening to the same extent if the grass goes for weeks without being cut, especially as it diverts some energy for growth into producing pollen and seed. (This turfgrass flowering also might be a consideration for people with bad grass pollen allergies.)

This topic of bee resources in lawns as addressed by the no-mow movement is touched upon by wildlife biologist Sam Droege in the native bee special episode of the University of Maryland Extension Garden Thyme Podcast from last summer.

Lawn alternatives, even if not purely native species, are another option when dealing with a lawn that is struggling. While a healthy lawn is providing more environmental services (carbon sequestration, erosion control, nutrient filtering, etc.) than a struggling lawn, if you do not wish to devote resources to improving its health and vigor, then converting those areas to non-lawn is more practical, even if a bit more expensive at first than just rehabbing the lawn. If a tolerance to regular foot traffic from people or pets is needed, then lawn is the best groundcover for this use and you might want to work to improve its health, but otherwise areas not being stepped-on can be planted with other species.

By Miri Talabac, Horticulturist, University of Maryland Extension Home & Garden Information Center. Miri writes the Garden Q&A for The Baltimore Sun and Washington Gardener Magazine. 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. Our horticulturists are available to answer your questions online, year-roundYou can also connect with your local County/City Extension Office and Master Gardener local programs.