The Weeds in Your Bird Seed

With February comes the return of the Great Backyard Bird Count, a weekend-long, worldwide, bird counting event that Sierra and I have enjoyed participating in for the past few years. While you can choose to count birds anywhere birds are found, part of the appeal of the event is that it can be done from the comfort of one’s own home simply by watching for birds to appear right outside the window. If there are bird feeders in your yard, your chances of seeing birds are obviously improved. Watch for at least fifteen minutes, record the number and species of birds you see, then report your sightings online. It’s for science!

Feeding and watching birds are popular activities. In the United States alone, as many as 57 million households put out food for birds, spending more than $4 billion annually to do so. While there are a variety of things one can purchase to feed birds – suet, berries, mealworms, etc. – the bulk of that money is likely spent on bags of bird seed (also referred to as bird feed). Bird seed is a relatively cheap and easy way to feed a wide variety of birds. Unfortunately, it’s also a great way to introduce new weeds to your yard.

Bird seed contaminated with noxious weed seeds is not a new problem. It has been a concern for decades, and some countries have taken regulatory steps to address the issue. In the United States, however, there are no governmental regulations that address weed seed contamination in bird seed.  With this thought in mind, researchers at the University of Missouri screened a large sampling of bird seed mixes to determine the number and species of weed seeds they harbored, as well as their viability and herbicide resistance. Their results were published last year in Invasive Plant Science and Management.

The researchers examined 98 different bird seed mixes purchased from retail locations in states across the eastern half of the U.S. The seeds of 29 weed species were recovered from the bags, including at least eight species of grasses and several annual and perennial broadleaf weeds. 96% of the mixes contained one or more species of Amaranthus, including Palmer’s amaranth (Amaranthus palmeri), which was found in 27 mixes and which the researchers refer to as “the most troublesome weed species in agroecosystems today.” About 19% of amaranth seeds recovered germinated readily, and five of the seed mixes contained A. tuberculatus and A. palmeri seeds that, once grown out, were found to be resistant to glyphosate, the active ingredient in a commonly used herbicide.

Redroot pigweed (Amaranthus retroflexus) is one of several weedy amaranth species commonly found in bird seed mixes (illustration credit: wikimedia commons)

The seeds of grass weeds were found in 76% of the bird seed mixes and included three species of foxtail (Setaria spp.), as well as other common grasses like large crabgrass (Digitaria sanguinalis) and barnyardgrass (Echinochloa crus-galli). Bird seed ingredients that seemed to favor grass seed contamination included wheat, grain sorghum, and proso millet, three crops that are also in the grass family. No surprise, as grass weeds are difficult to control in crop fields when the crop being grown is also a grass.

After amaranths and grasses, ragweed (Ambrosia artemisiifolia) was the third most common weed found in the mixes. This was a troubling discovery since populations of this species have shown resistance to a number of different herbicides. Moving ragweed to new locations via bird seed could mean that the genes that give ragweed its herbicide resistance can also be moved to new locations. Kochia (Bassia scoparia), another weed on the Weed Science Society of America’s list of top ten most troublesome weeds, was also found in certain bird seed mixes, particularly when safflower was an ingredient in the feed.

A similar study carried out several years earlier at Oregon State University found the seeds of more than fifty different weed species in ten brands of bird feed commonly sold at retail stores. Ten of the weeds recovered from the mixes are on Oregon’s noxious weed list. Both studies demonstrate how bird seed can be a vector for spreading weed seeds – and even new weed species and herbicide-resistant genes – to new locations. Weeds found sprouting below bird feeders can then potentially be moved beyond the feeders by wind and other dispersal agents. Weed seeds might also be moved to new locations inside the stomachs of birds.

Addressing this issue can be tackled from several different angles. Growers and processors can improve their management of weed species in the fields where bird seed is grown and do a better job at removing weed seeds from the mixes after they are harvested. Government regulations can be put in place that restrict the type and quantity of weed seeds allowed in bird feed. Further processing of ingredients such as chopping or shelling seeds or baking seed mixes can help reduce the presence and viability of weed seeds.

Processed bird feed like suet is less likely to harbor viable weed seeds (photo credit: wikimedia commons)

Consumers can help by choosing bird feed that is processed or seedless like sunflower hearts, dried fruit, peanuts, suet cakes, and mealworms, and can avoid seed mixes with a large percentage of filler ingredients like milo, red millet, and flax. Attaching trays below feeders can help collect fallen seeds before they reach the ground. Bird seed can also be avoided all together, and feeding birds can instead be done by intentionally growing plants in your yard that produce food for birds. By including bird-friendly plants in your yard, you will also have a better chance of seeing a wide variety of birds during the Great Backyard Bird Count.

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Winter Trees and Shrubs: Northern Catalpa

The names of plants often contain clues that can either help with identification or that tell something about the plant’s history or use. The name, catalpa, is said to be derived from the Muscogee word, katałpa, meaning “winged head,” presumably referring to the tree’s winged seeds. Or maybe, as one writer speculates, it refers to the large, heart-shaped, floppy leaves that can make it look like the tree is “ready to take flight.” Or perhaps it’s a reference to the fluted, fused petals of the tree’s large, tubular flowers. I suppose it could mean any number of things, but I’m sticking with its seeds, which are packed by the dozens in the tree’s long, slender, bean-like fruits. The seeds are flat, pale brown, and equipped with paper thin, fringed appendages on either side that assist in wind dispersal – wings, in other words.

winged seeds of northern catalpa (Catalpa speciosa)

Catalpa speciosa, or northern catalpa, is a relatively fast growing, short-lived tree native to the Midwest and one of only two species in the genus Catalpa found in the United States. Its distribution prior to the arrival of Europeans appears to have been restricted to a portion of the central Mississippi River valley, extending west into Arkansas, east into Tennessee, and north into Illinois and Indiana. It has since been widely planted outside of its native range, naturalizing in areas across the Midwest and eastern US. Early colonizers planted northern catalpa for use as fence posts, railroad ties, and firewood. Its popularity as an ornamental tree is not what it once was a century ago, but it is still occasionally planted in urban areas as a shade tree. Its messiness – littering the ground below with large leaves, flowers, and seed capsules – and its tendency to spread outside of cultivation into natural areas are reasons why it has fallen out of favor with some people.

The oval to heart-shaped, 8 to 12 inch long leaves with long petioles rotting on the ground below the tree are one sure sign that you’ve encountered a catalpa in the winter time. The leaves are some of the first to fall at the end of the growing season, briefly turning an unmemorable yellow before dropping.

leaf of northern catalpa (Catalpa speciosa) in the winter with soft hairs on the underside still visible

The leaf arrangement on northern catalpa is whorled and sometimes opposite. The twigs are easy to identify due to several unique features. They are stout, round, and grayish brown with prominent lenticels. The leaf scars are large, rounded, and raised up on the twig, looking a bit like little suction cups. They are arranged in whorls of three, with one scar considerably smaller than the other two. A series of bundle traces inside the scar form an ellipse. The leaf buds are tiny compared to the scar and are protected by loose, pointed, brown bud scales. Northern catalpa twigs lack a terminal bud. In the winter, seed capsules or the stalk of an old inflorescence often remain attached to the terminal end of the twig. The pith inside of the twig is thick, white, and solid.

twig of northern catalpa (Catalpa speciosa)

pith inside twig of northern catalpa (Catalpa speciosa)

Another common name for Catalpa speciosa is cigar tree, a name that comes from its up to 18 inch long, cigar-like seed capsules that hang from the otherwise naked tree throughout the winter. The sturdy, cylindrical pod starts out green in the summer and turns dark brown by late fall. Seed pods that haven’t fallen or already split open will dehisce in the spring time, releasing their papery seeds to the wind.

fruits of northern catalpa (Catalpa speciosa) hanging from the tree in the winter

The young bark of northern catalpa is thin and easily damaged. As it matures, it becomes furrowed with either scaly ridges or blocky plates. Mature trees are generally twisted at the base but otherwise grow straight, reaching 30 to 60 feet tall (sometimes taller) with an open-rounded to narrow-oval crown.

maturing bark of northern catalpa (Catalpa speciosa)

Northern catalpa is one of the last trees to leaf out in the spring. In late spring or early summer, 10 inch long clusters of white, tubular flowers are produced at the tips of stems. Before the flowers open, they look a bit like popped popcorn, reminding me of a song from my childhood (which I will reluctantly leave right here). The margins of its trumpet-shaped petals are ruffled and there is yellow, orange, and/or purple spotting or streaking on the inside of the tubes.

flower of northern catalpa (Catalpa speciosa) just before it opens

More Winter Trees and Shrubs on Awkward Botany:

Winter Trees and Shrubs: Netleaf Hackberry

Boise, Idaho is frequently referred to as the City of Trees despite being located in a semiarid region of the Intermountain West known as the sagebrush steppe where few trees naturally grow. It earns this moniker partly because the name Boise is derived from the river that runs through it (the Boise River), which was named La Rivere Boisse, or The Wooded River, by early French trappers. Although it flows through a largely treeless landscape, The Wooded River was an apt name on account of the wide expanse of cottonwoods and willows that grew along its banks. The fervent efforts of early colonizers to plant trees in large numbers across their new city also helped Boise earn the title, City of Trees. Today, residents continue the legacy of planting trees, ensuring that the city will remain wooded for decades to come.

As is likely the case for most urban areas, the majority of trees being planted in Boise are not native to the region. After all, very few tree species are. However, apart from the trees that flank the Boise River, there is one tree in particular that naturally occurs in the area. Celtis reticulata, commonly known as netleaf hackberry, can be found scattered across the Boise Foothills amongst shrubs, bunchgrasses, and wildflowers, taking advantage of deep pockets of moisture found in rocky outcrops and draws.

The western edge of netleaf hackberry’s range extends to the northwest of Boise into Washington, west into Oregon, and down into California. The majority of its range is found south of Idaho, across the Southwest and into northern Mexico, then east into the prairie regions of Kansas and Oklahoma. Previously placed in the elm family, it is now considered a member of the family Cannabaceae (along with hemp and hops). It’s a relatively small, broad tree (sometimes a shrub) with a semi-rounded crown. It grows slowly, is long-lived, and generally has a gnarled, hardened, twisted look to it. It’s a tough tree that has clearly been through a lot.

The leaves of Celtis reticulata are rough, leathery, and oval to lance shaped with serrate or entire leaf margins. Their undersides have a distinct net-like pattern that gives the tree its common name. A very small insect called a hackberry psyllid lays its eggs inside the leaf buds of netleaf hackberries in the spring. Its larvae develop inside the leaf, feeding on the sugars produced during photosynthesis, and causing nipple galls to form in the leaves. It’s not uncommon to see a netleaf hackberry with warty-looking galls on just about every leaf. Luckily, the tree doesn’t seem to be bothered by this.

fallen leaves of netleaf hackberry (Celtis reticulata) with nipple galls

The fruit of netleaf hackberry is a pea-sized drupe that hangs at the end of a pedicel that is 1/4 to 1/2 inch long. Its skin is red-orange to purple-brown, and its flesh is thin with a large seed in the center. The fruits, along with a few random leaves, persist on the tree throughout the winter and provide food for dozens of species of birds and a variety of mammals.

persistent fruit of netleaf hackberry (Celtis reticulata)

Celtis reticulata is alternately branched. Its twigs are slender, zig-zagging, and often curved back towards the trunk. They are reddish-brown with several pale lenticels and have sparse, fine, short hairs that are hard to see without a hand lens. The leaf scars are small, half-round, and raised up from the twig. They have three bundle scars that form a triangle. The buds are triangle-shaped with fuzzy bud scales that are slightly lighter in color than the twig. The twigs are topped with a subterminal bud, and the pith (the inner portion of the twig) is either chambered or diaphragmed and difficult to see clearly without a hand lens. 

twigs of netleaf hackberry (Celtis reticulata)

The young bark of netleaf hackberry is generally smooth and grey, developing shallow, orange-tinged furrows as it gets older. Mature bark is warty like its cousin, Celtis occidentals, and develops thick, grey, corky ridges. Due to its slow growth, the bark can be retained long enough that it becomes habitat for extensive lichen colonies.

bark of young netleaf hackberry (Celtis reticulata)

bark of mature netleaf hackberry (Celtis reticulata)

Netleaf hackberry is one of the last trees to leaf out in the spring, presumably preserving as much moisture as possible as it prepares to enter another scorching hot, bone-dry summer typical of the western states. Its flowers open around the same time and are miniscule and without petals. Their oversized mustache-shaped, fuzzy, white stigmas provide some entertainment for those of us who take the time to lean in for a closer look.

spring flowers of netleaf hackberry (Celtis reticulata)

More Winter Trees and Shrubs on Awkward Botany:

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Photos of netleaf hackberry taken at Idaho Botanical Garden in Boise, Idaho.

2020: Year in Review

This past year was certainly not the year that any of us hoped it would be. We all know why, so there’s no reason to get into it here. Point being, posts on Awkward Botany were a bit fewer and further between in 2020. My day job kept me busier than usual, and my motivation to do much else was pretty much zapped. Regardless, I’m still pleased with what I was able to put out into the world. I’m particularly excited about my new Weeds of Boise project, in which I attempt to catalog the wild urban flora of my hometown. Expect more of that in 2021.

Certainly the biggest news of 2020 is that Sierra (a.k.a. Idaho Plant Doctor) and I bought a house! We started looking in earnest late last summer and weren’t having much luck. Just as we were considering putting our dreams on hold for a bit, we came across a little house in a neighborhood we love. The house was perfect for us, with a big pollinator garden out front and a series of garden boxes in various locations around the property, along with a nice chicken coop (five chickens included!). It was a tiny urban farm looking for new owners, and we were the chosen ones! I like to think that we bought a garden, and it came with a house. This year will be a year of discovery as we watch the yard come to life and fulfill our dream of having a garden of our own. We will definitely keep you posted.

But that’s not all. On the 1st of January, Sierra and I got married in a tiny ceremony in our new backyard. We had planned on getting married in the fall of 2020, but the pandemic quickly put those plans to rest. Now, with a place of our own and a desire to put a tough year behind us, we started the new year off on a positive note. With a number of precautions in place, we were able to celebrate the start of our new lives together with some of our close friends and family. Despite it being the middle of winter, the weather was perfect for our little outdoor gathering. The love and generosity we were shown from so many people that weekend is something we will never forget. 

two nerds getting married

What follows are the usual items found in a Year in Review post – ways you can follow Awkward Botany on social media, links to donate monetarily to Awkward Botany (no pressure), and posts from 2020 that are part of new and ongoing series of posts. New in 2021 is the Awkward Botany Bookshop. Bookshop is a site that makes it possible to purchase books online and support local bookstores in the process. When you buy books through Awkward Botany’s page, we receive a small percentage of the sale, which helps us continue to put out more of the plant nerdy content you’ve come to expect. There is a small selection of books in the store now, and I’ll continue to add more, so check back often. If there are books you’d like me to add to the store, please let me know. 

Follow Awkward Botany on Social Media:

Donate to Awkward Botany:

A Selection of Awkward Botany Posts from 2020

Botany in Popular Culture

Zine and Book Reviews

Weeds of Boise

Tea Time

Podcast Reviews

Awkward Botanical Sketches

Winter Trees and Shrubs

All the Plant Shows, part two

Plant podcasts are big these days, or at least that’s what it seems, which is why this has turned into a multi-part post (see part one). While in the process of compiling a list of plant podcasts that I’ve become aware of, I keep stumbling onto more. Which is great! It’s a trend that I hope continues. As it continues, I will go on compiling them here until we have ourselves a list of All the Plant Shows!

Planthropology – Plants plus anthropology equals Planthropology. This podcast covers all the many ways that plant lives and human lives intersect and features conversations with plant people about their love of plants and the work they do that involves plants. Vikram (the host) is a chatty and genial guy and a great twitter follow.

The Plant Prof – Another Vikram joint. This spin-off of Planthropology features Vikram sans guests talking about an assortment of plant-related topics. Each episode is only a few minutes long. Quick, casual, and easy to digest.

Plant Daddy Podcast – Houseplants are quite popular these days, likely due to the growing number of people living in dense urban areas. Apartment living generally means that if you want to garden, you have to do it indoors and/or on a balcony. With increased interest in indoor growing comes a slew of podcasts about it. Plant Daddy Podcast is one of the best. Matthew and Stephen really know their plants and have years of combined experience caring for a vast number of species. Other plant experts occasionally join the show to talk about the specifics of cultivating and caring for plants in small spaces.

Plantrama – Mainly a gardening podcast, but very plant-focused. C.L. and Ellen are experienced gardeners and quite knowledgeable about plants. Episodes come out regularly, and each one is under 30 minutes. In that time, the hosts cover at least three topics. Juniper berries, begonias, and orchid pots, for example. Or cherry tomatoes, silverberry, and saving seed. It’s two good friends having a chat about plants, and you get to listen in.

The Plant Kiki – A kiki is a casual conversation among friends. When plants are a major theme of the discussion, it’s a plant kiki! For each episode, Colah, of Black in the Garden podcast (another must listen), brings together a group of friends to talk about plants and whatever else comes up. The conversations are lively, humorous, insightful, and fun. If you enjoy exploring questions like “If Beyoncé were a plant, what plant would she be?” this podcast is for you.  

Crime Pays But Botany Doesn’t – Joe is a self-described misanthrope. He doesn’t care much for people, but he loves plants (and geology). This podcast is similar to Joe’s You Tube channel of the same name, in that it’s mostly him describing his time botanizing in various locations across North America and beyond. Expletive-filled rants help fill the time. Occasionally Joe brings on a guest to talk about plants (or trains). With hours and hours of content available, this is easily one of the best and most entertaining plant shows around.

The Taproot – A podcast produced by Plantae, a plant science hub created and managed by the American Society of Plant Biologists. Each episode is an interview with an individual who is working in or studying plant science. There are discussions about the work that went into a particular plant science journal article, as well as conversations about navigating academia and professional life. It’s a great source of information for students and professionals, with excellent tips on how to succeed in educational pursuits and beyond.   

PlantNetwork Podcast PlantNetwork is an organization that supports public gardens and professional gardeners in Britain and Ireland. Their podcast is a series of short interviews with people who work at public gardens or in some other capacity in the horticulture industry.

Speaking of public gardens, educating the public about plants is a mission of botanic gardens and arboreta. Some botanic gardens do this through podcasts. Below are a few that I have come across. If you happen to be aware of others, please let me know.

Branch Out – A plant science podcast produced by The Royal Botanic Garden Sydney with a catalog consisting of six seasons covering a wide array of plant-based topics. Vanessa geeks out about plants and nature with a bevy of incredible guests. No surprise, much of the content concerns Australian plants, gardens, agriculture, and ecology. But who isn’t fascinated by Australia’s flora and fauna? The production on each episode is excellent, and the stories are captivating. 

Plant Power – A short series of podcasts produced by North Carolina Botanical Garden highlighting just how essential plants are to life on earth. Brief conversations about climate change, protecting pollinators, growing and conserving native plants, etc. 

Botanical Mystery Tour – A delightful podcast from Chicago Botanic Garden that takes the stories of plants in popular culture and explores the science behind them. In each episode, a staff member at CBG joins the hosts, Jasmine and Erica, to discuss the topic and talk about their work at the Garden. Whenever botany shows up in popular culture, it’s an event worth celebrating. It’s good to know there’s a podcast devoted to this cause.

Unearthed: Mysteries from an Unseen World – A podcast series from Royal Botanic Gardens Kew hosted by James Wong. Each episode is a mini audio documentary investigating a particular mystery, story, or current event involving plants (or, in the case of one episode, fungi). This podcast has great production and excellent, fact-based storytelling – exactly the sort of thing you’d expect from a place like Kew.

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These certainly aren’t all the plant shows. Part three is in the making. In the meantime, is there a particular plant-themed podcast (or podcast episode) that you enjoy and would like to recommend? If so, share it with us in the comment section below.

Winter Trees and Shrubs: Eastern Redbud

Botanizing doesn’t have to end when the leaves fall off the trees and the ground goes frozen. Plants may stop actively growing during this time, but they are still there. Some die back to the soil level and spend the entire winter underground, leaving behind brown, brittle shells of their former selves. Others, particularly those with woody stems, maintain their form (although many of them leafless) as they bide their time while daylength dips and rises again, bringing with it the promise of warmer weather. Plants that leave us with something to look at during the winter can still be identified. Without foliage or flowers to offer us clues, we rely instead on branches, bark, and buds to identify woody species. In some cases, such features may even be more helpful in determining a certain species than their flowers and foliage ever were. Either way, it’s a fun challenge and one worth accepting if you’re willing to brave the cold, hand lens and field guides in tow.

In this series of posts I’ll be looking closely at woody plants in winter, examining the twigs, buds, bark, and any other features I come across that can help us identify them. Species by species, I will learn the ropes of winter plant identification and then pass my findings along to you. We’ll begin with Cercis canadensis, an understory tree commonly known as eastern redbud.

Eastern redbud is distributed across central and eastern North America, south of southern Michigan and into central Mexico. It is also commonly grown as an ornamental tree outside of its native range, and a number of cultivars have been developed for this purpose. Mature trees reach up to 30 feet and have short trunks with wide, rounded crowns. Its leaves are entire, round or heart-shaped, and turn golden-yellow in the fall. Gathered below the tree in winter, the leaves maintain their shape and are a light orange-brown color.

fallen leaf of eastern redbud (Cercis canadensis)

Eastern redbud is alternately branched with slender, zig-zagging twigs that are dark reddish-brown scattered with several tiny, light-colored lenticels. Older sections of branches are more grey in color. Leaf scars (the marks left on twigs after leaves fall) are a rounded triangle shape and slightly raised with thin ridges along each side. The top edge of the leaf scar is fringed, which I found impossible to see without magnification. Leaf buds are egg-shaped and 2-3 mm in length with wine-red bud scales that are glabrous (smooth) with slightly white, ciliate margins. Descriptions say there are actually two buds – one stalked and one sessile. If the second bud is there, it’s miniscule and obscured by the leaf scar. I haven’t actually been able to see one. Twigs lack a terminal bud or have a tiny subterminal bud that points off to one side. The pith of the twigs is rounded and pale pink. Use sharp pruners or a razor blade to cut the twig in half lengthwise to see it.

twig and buds of eastern redbud (Cercis canadensis)

Bark is helpful in identifying woody plants any time of year, but is especially worth looking at during the winter when branches have gone bare. The bark of young eastern redbud is grey with orange, furrowed streaks running lengthwise along the trunk. In mature trees, the bark is gray, scaly, and peels to reveal reddish-brown below.

bark of young eastern redbud (Cercis canadensis)

bark of mature eastern redbud (Cercis canadensis)

Eastern redbud is in the bean family (Fabaceae) and its flowers and fruits are characteristic of plants in this family. Fruits can persist on the tree throughout the winter and are another way to identify the tree during the off-season. Seed pods are flat, dark red- or orange-brown, and up to 2.5 inches long with four to ten seeds inside. The seeds are flat, round, about 5 millimeters long, and ranging in color from orange-brown to black.

persistent fruits of eastern redbud (Cercis canadensis)

seeds of eastern redbud (Cercis canadensis)

Eastern redbud flowers in early spring before it has leafed out. Clusters of bright pink flowers form on old branches rather than new stems and twigs. Sometimes flowers even burst right out of the main trunk. This unique trait is called cauliflory.

cauliflory on eastern redbud (Cercis canadensis)

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Photos of eastern redbud taken at Idaho Botanical Garden in Boise, Idaho.

All the Plant Shows, part one

Podcasts are among the most accessible and powerful mediums through which we can tell and hear the stories of plants. The popularity of podcasts is evidence that if we want to share our love of plants with the world and get others to love them too, we have to be using podcasts to do it. They are essential tools in the communication of plant science and, when used effectively, they may even help the plant-indifferent gain a lifelong appreciation for the botanical world.

As a longtime listener of podcasts and a lover of plants, I have been on a constant search for podcasts about plants. I’ve even included reviews of some of those podcasts here on this blog (see reviews for Gastropod, In Defense of Plants, Native Plant Podcast, The Field Guides, Botanical Mystery Tour, and Plants and Pipettes). I’m not sure if it’s just me, but it seems that in the past few years, plant podcasts have experienced a boom. There are definitely more plant-themed podcasts out there now than I recall seeing when I first went in search of them nearly a decade ago, and I imagine there are more out there than I’m even aware of. Seeing that, I figured it was time to collect all those podcasts into a single post (or series of posts). Each podcast is deserving of a post of its own, but in the meantime, a few sentences will have to do.

When I say plant podcasts, I realize that could include gardening podcasts. Why shouldn’t it? After all, what’s gardening without plants? However, this isn’t a gardening blog, and even as an avid gardener (and a professional one), I don’t really listen to many gardening podcasts. A few gardening or gardening-adjacent podcasts are included here either because I particularly enjoy them or because they tend to go beyond the act of gardening and are particularly known for giving plants the center stage.

In Defense of Plants – Long-running and consistent, this is the go-to podcast (and website) for learning about plants and plant science. It’s adamant about telling the stories of plants for plant’s sake. A typical episode features the host, Matt, interviewing experts and plant science professionals about their specific area of study or work.

Native Plant Podcast – Going strong for 5 years now, this podcast is exactly what it says it is – a podcast about native plants. There is a major focus on gardening and landscaping with native plants, which the main host, John, has been doing since before it was cool. Every episode ends with a pet story and a toast.

The Field Guides – Easily one of my favorite podcasts, largely because the hosts are so affable and are clearly having fun, but also because the format is so unique. Each episode, Steve and Bill pick a natural history topic and then walk around in a natural area talking about it – the sounds of footsteps and the wildlife around them included. Not specifically a plant podcast, but plants come up in every episode even if they aren’t the main topic of discussion.

Plants and Pipettes – A podcast focused mainly on what’s going on inside of plants – molecular plant biology, in other words. If that doesn’t sound like your thing, give it a shot anyway. The hosts are fun and funny, good at explaining things, and find lots of other plant and plant-adjacent things to talk about in addition to molecular biology. Plus, you are probably more interested in cellular-level interactions than you think you are.

Plant Crimes – True crime stories involving plants. Well-researched and well-crafted tales about things like missing water lilies, redwood poaching, and how lemons and the mob are related. Ellen interviews people involved in or knowledgeable about the incidents and weaves excerpts from those conversations into her storytelling. I’m anxiously awaiting the second season.

Plant Book Club – Ellen (of Plant Crimes) and Tegan and Joram (of Plants and Pipettes) read a plant-themed book and then talk about it. Everything you love about their individual podcasts combined into one. It’s a tour de force!

Botanize! – An audio series produced by Encyclopædia Britannica. Each episode is a brief exploration of a plant, group of plants, or some other plant-centric topic. It’s way more entertaining than reading an encyclopedia entry. Melissa is a charismatic host who is clearly excited about plants and nature. Her and her occasional guests add personal experiences to the science of plants.

Cultivating Place – This is a perfect example of a more-than-just-gardening gardening podcast. In Jennifer’s words, “gardens encourage a direct relationship with the dynamic processes of the plants, animals, soils, seasons, and climatic factors that come to bear on a garden, providing a unique, and uniquely beautiful, bridge connecting us to our larger environments — culturally and botanically.” Each episode features a conversation with a grower, gardener, naturalist, scientist, artist, or otherwise and, while many of the episodes are garden-focused, others go beyond the garden to discuss other plant-y things like seed banking (see this recent episode with Dr. Naomi Fraga).

A Way to Garden – This is perhaps a more typical gardening podcast, but easily one of the best ones out there. My belief is that gardens ought have a purpose that goes beyond their aesthetic qualities. They should be ecologically functional, acting as habitat rather than destroying it. Margaret seems to think so too. Plus, she loves birds and is a great conversationalist, and who can resist her regular check-ins with Ken Druse?


This is part one of (at least) two. There are many more podcasts to highlight here. In the meantime, is there a particular plant-themed podcast (or podcast episode) that you enjoy and would like to recommend? If so, share it with us in the comment section below.

Seed Shattering Lost – The Story of Foxtail Millet

For a plant to disperse its seeds, it must first let go of them. Sounds obvious, but it is a key step in the dispersal process and an act that is actually coded in a plant’s DNA. As fruits ripen and seeds mature, an abscission layer is formed that separates the seed-bearing fruits from the plant. No longer attached to their parents, seeds are left to their own devices. If all goes well, they will find themselves in a suitable location where they can germinate and grow into a whole new plant, fully equipped to make seed babies of their own.

The releasing of mature seeds is known as shattering, a term most commonly used in reference to grasses and plants with dehiscent seed pods (i.e. fruits that split open when ripe, such as those in the bean and mustard families). In grasses, seeds form along a central stem called a rachis. As the seeds ripen, they separate from the rachis and drop from the plant. In some cases, the rachis is brittle and a section of it breaks off with each seed that falls.

Seed shattering is not a desirable trait when it comes to food crops. It’s easy to see how yields can be poor if seeds disperse before they are harvested. Thus, an essential step in domesticating certain agricultural crops was selecting plants that lacked this particular trait. Instead of dropping mature seeds, such plants hold on to them, making them easy to collect. A simple and naturally occurring mutation in the genes of these plants allowed early farmers to select varieties that were more ideal for agriculture than their wild progenitors.

Genetic studies of agricultural crops have located genes in a number of species that code for seed shattering, confirming that domestication in many cases involved selecting plants with this gene turned off. A recent study, published in Nature Biotechnology (October 2020), took a different route in locating this gene, looking instead at a weedy, wild relative of a crop that was domesticated at least 8000 years ago. Green foxtail (Setaria viridis) is the wild antecedent of foxtail millet (Setaria italica), a crop that, while still commonly grown for food in parts of Asia, is mostly grown for hay, silage, and bird seed in North America. Recently, interest in foxtail millet and other millets (a term used to refer to the grains of several different species of grasses) is on the rise due to the ability of these crops to tolerate drought and heat.

Illustration of three Setaria species from Selected Weeds of the United States (Agriculture Handbook No. 366) published in 1970

Setaria viridis is an abundant, widespread weed adapted to human disturbance. It’s of Eurasian origin but has been present in North America since the early 1800’s and was likely introduced both intentionally and accidentally. It’s an annual grass with prominent, bristly flowerheads that are easily recognizable and the reason for its common name, green foxtail. A handful of other closely related, similar-looking species are also common weeds in North America. Due to useful traits including its short life cycle, small genome, and self-fertility, S. viridis has been used frequently as a model species to carry out a variety of scientific studies. The study referred to above aimed to further enhance the use of green foxtail, particularly when it comes to crop science.

Researchers traveled across the United States collecting nearly 600 samples of green foxtail in order to better understand its genome. They found that the North American population of green foxtail is composed of multiple introductions and that, as the species has followed humans around, it has quickly adapted to diverse climates found across the continent. In examining the genome, they were able to identify the genetic underpinnings for three traits that have importance to agriculture: response to climate, leaf angle (which is used as a predictor of yield in grain crops), and seed shattering.

foxtail millet (Setaria italica) via wikimedia commons

The seed shattering gene – which the researchers named Less Shattering 1 (SvLes1) – was an especially interesting discovery. When compared to the orthologous gene found in foxtail millet, they found that a frameshift mutation had caused a disruption in the gene, turning it off. Using CRISPR (a gene editing tool) they were able to recreate a similar interruption in green foxtail, which resulted in a loss of seed shattering similar to that of foxtail millet. It became clear that selecting plants with this mutation was an essential step in the domestication of this ancient grain.

An excerpt about seed shattering from Fruit from the Sands by Robert N. Spengler III: 

In many of the world’s domesticated grains, especially those from the founder crops of southwest Asia (i.e. wheat and barley), the earliest phenotypical trait of domestication that archaeobotanists look for is a tough rachis, the small stem by which an individual grain or small cluster of grains is attached to the ear. In their wild form, most grains are programmed to detach easily after the grain ripens; however, in domesticated cereals, the grains remain attached to the ear throughout the harvesting process. This change is an inadvertent result of human harvesting with sickles: as people reap their harvest, the grains with a brittle rachis are dropped and those with a tough rachis are collected, stored, and replanted for successive harvests.

Further Reading:

Tea Time: Lemon Balm Tea

Cooler weather has me thinking about hot tea again. This time around I decided to go with something I’ve already tried and know that I like. Despite the fact that lemon balm can be quite abundant and readily available, I don’t really drink it that often. Yet, considering claims made regarding its calming nature, this is definitely the year to have it.

lemon balm (Melissa officinalis)

Melissa officinalis is an herbaceous perennial native to the Mediterranean Basin and beyond. It has been widely planted outside of its native range and has become naturalized – some might say weedy – in many parts of the world. It self-sows easily and also spreads readily via stolons and/or rhizomes. It isn’t picky about soil type and grows well in both sun and part shade. Lemon balm is in the mint family and acts in a similarly aggresive way to some of its relatives, but luckily isn’t nearly as tenacious as mint in its tendency to dominate a garden bed.

The leaves of lemon balm have a wrinkled appearance, are triangular or wedge-shaped with toothed margins, and are arranged oppositely on square stems up to three feet tall. Small, white or pale yellow (sometimes pale pink) flowers are inconspicuous and produced in the axils of leaves. They are often sparse enough to be hardly noticeable. This plant’s aesthetic appeal is all about its pleasant and prolific green foliage. Yet, despite the simplicity of its flowers, lemon balm is known for being attractive to bees and is often propagated specifically to feed honeybees. In fact, the genus name Melissa apparently means honeybee in Ancient Greek.

lemon balm flower

The leaves of lemon balm can be consumed fresh or dried and have a number of other uses besides tea. They have a sweet, lemon-like scent and, like so many other herbs with a long history of human use, have a wide array of medicinal claims associated with them. Many sources agree on lemon balm’s ability to calm the nerves, reduce stress and anxiety, and fight off insomnia. According to The Herb Society of America’s Essential Guide to Growing and Cooking with Herbs, lemon balm “has been used as a relaxing agent and as an aid to restful, nightmare-free sleep.” Sounds like I could use more lemon balm in my life.

dried lemon balm leaves

Lemon balm tea can be made with either fresh or dried leaves, but fresh leaves seem to make a more flavorful tea. I had only tried tea made from dried leaves until recently and have decided that I prefer fresh leaves. Simply harvest a few leaves, cut or tear them apart to release the lemony flavor, place them in a cup, and cover them in hot water. Some recipes (like this one) suggest adding honey, while others mix lemon balm with additional herbs known for their lemon-like flavor or relaxing nature (lemon thyme and lemon verbena, for example). Sierra was immediately taken by lemon balm tea when she tried it – in contrast to her experience with violet leaf tea – and even said it was right up there with her preferred black teas. I’m not surprised, as it is one of my favorite teas as well.

lemon balm tea made with freshly harvested leaves

More Tea Time Posts on Awkward Botany:

A Few More Snags Near Ketchum

Nearly a year has passed since Sierra and I took a trip to Ketchum, Idaho and I reported on some of the snags we encountered there. After months without a break, we finally had the chance to get away for a few days, and since we were desperate for some time off and a change of scenery, we couldn’t turn it down. Plus, we were heading back to Ketchum, so I knew I’d get to check out a few more snags. I was stoked.

I’m obsessed with trees, and my preference is for live ones (generally speaking), but dead trees are certainly gaining in popularity. After all, a dead tree isn’t truly dead. As its corpse slowly rots, it continues to harbor and support life inside and out in a substantial way. Forests need dead trees just as much as they need live trees. Plus, ecology aside, dead trees are no less photogenic than any other tree.

Death isn’t all bad. New life springs from decay. Given our current state of affairs, we need this reminder, and snags offer it in spades. As Sierra and I pulled up to the Apollo Creek trailhead, we looked out onto a section of forest that had clearly been ravaged by fire in the not too distant past. Acres of standing and fallen burned out trees bore witness to this fact. Yet among the dead, life flourished, as dozens of songbirds actively foraged on and around the charred trees. They were there for the insects that were feeding on the dead wood, fueling themselves for fall migration. In the spring, when the birds return, some of them may even nest in the cavities of the dead trees. They will feed again on the insects and raise up a new generation of songbirds that will do the same. In and among snags there are myriad examples just like this, showing us the countless ways in which death supports new life.

What follows is a small sampling of the snags we encountered this time around on our trip to Ketchum.

post-fire snag among many other snags

a series of cavities in a post-fire snag

snag surrounded by live trees

three new snags

fallen snag

broken snag

new tree emerging from a nurse stump

not a snag, but one of many lupines we saw flowering along Apollo Creek Trail