Book Review: Good Weed Bad Weed

Distinguishing weeds from desirable plants is a skill that takes years of experience. If you’re not an avid gardener or a practiced naturalist, the distinction between the two groups may be blurry. There are weed identification guides aplenty, but even those aren’t always the most user-friendly and can often leave a person with more questions than answers. One of those questions may be, “Why is this plant considered a weed and not that one?” Through her book, Good Weed Bad Weed, Nancy Gift attempts to answer that question, offering much needed nuance to a regularly vilified group of plants.

In the introduction, Gift acknowledges that the term “good weed” sounds like an oxymoron. A weed, by definition, is an unwanted plant, an interloper and a troublemaker, without value or merit. What could be good about that? Gift, on the other hand, asserts that “it is a weakness of the English language that weeds are universally unwanted.” We need a word that describes plants that may have weedy characteristics but some redeeming qualities as well. For now, Gift uses “volunteer” – “a plant that comes up without being planted or encouraged” – suspending judgement until its performance can be fairly assessed.

Good Weed Bad Weed is a weed identification guide designed for beginners, for those wondering if their yard is “infested or blessed.” It is specifically concerned with weeds commonly found in lawns and garden beds, and “not meant to apply to farm fields or any other landscape.” It sets itself apart from other identification guides by organizing weeds into three categories: Bad Weeds, Not-So-Bad Weeds, and Good Weeds. Each plant profile includes a description, notes about benefits as well as problems, and some recommendations for control. Assigning good/bad designations to these plants is bound to cause some heated debate and outright disagreement, and Gift acknowledges that; however, we all have our “unique judgement” about the plants we encounter in our landscapes, so as “weed-lovers-in-training,” Gift hopes that we can “make a few new friends in the plant kingdom” and, perhaps, a few less enemies.

For the ten plants that make the Bad Weeds list, the reasoning is pretty clear. They are highly competitive and difficult to control [foxtail (Setaria spp.), garlic mustard (Alliaria petiolata), and Canada thistle (Cirsium arvense)], they are poisonous to humans despite being beneficial to wildlife [poison ivy (Toxicodendron radicans ) and poison hemlock (Conium maculatum)], they are known allergens and otherwise unattractive [common ragweed (Ambrosia artemisiifolia)], or, like Japanese knotweed (Fallopia japonica), they are on the list of top 100 worst invasive species.

The other two categories are where more personal judgement comes into play. The twelve plants considered Not-So-Bad Weeds are said to have “admirable qualities despite some negatives.” Prostrate knotweed (Polygonum aviculare) provides excellent erosion control. Orange hawkweed (Hieracium aurantiacum), bull thistle (Cirsium vulgare), and musk thistle (Carduus nutans) are quite beautiful and highly beneficial to pollinators and other wildlife. Nutsedge (Cyperus spp.) is edible and easy to keep in check if you stay on top of it. Bindweeds (Convolvulus arvensis and Calystegia sepium) avoid the Bad Weeds list because their flowers are so appealing. Aesthetics really matter to Gift, which is made clear with the entry for common fleabane (Erigeron philadelphicus), which could have made the Good Weeds list were it not for its disappointing and forgettable floral display.

field bindweed (Convolvulus arvensis)

As for the Goods Weeds list, more plant species find themselves in this category than the other two categories combined. That being said, those who have strong, negative opinions about weeds should probably avoid this section of the book, lest they experience an unsafe rise in blood pressure upon reading it. But be advised that making the Good Weeds list doesn’t mean that there are no negatives associated with having these plants in your yard; it’s just that the positive qualities tend to overshadow the negatives.

Positive qualities include edible, medicinal, low growing, slow growing, easy to control, beneficial to wildlife, not a bully, hardly noticeable, uncommon, and soil building. Certain weeds are desirable in lawns because they are soft to walk on, like ground ivy (Glechoma hederacea), yarrow (Achillea millefolium), and moss. Other weeds, like self-heal (Prunella vulgaris), stay green year-round and don’t leave ugly, brown patches when they die or go dormant. Still others, like bird’s-foot trefoil (Lotus corniculatus), black medic (Medicago lupulina), and clovers (Trifolium spp.) fix nitrogen, providing free fertilizer. Gift notes that, for those who keep chickens, weeds like common sorrel (Rumex acetosa) and cuckooflower (Cardamine pratensis) are great chicken feed.

Speaking of eating weeds, Gift concludes her book with four pages of recipes. The “Weedy Foxtail Tabouli” is particularly intriguing to me. Reading this book definitely requires an open mind, and some people simply won’t agree that any weed should ever be called “good.” Gift seems okay with that. She calls herself a “heretical weed scientist,” insisting that “a weed is in the eye of the beholder.” As “beholders,” I hope we can all be a little more like Nancy Gift.

A weedy lawn (photo credit: wikimedia commons)

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When Urban Pollinator Gardens Meet Native Plant Communities

Public concern about the state of bees and other pollinating insects has led to increased interest in pollinator gardens. Planting a pollinator garden is often promoted as an excellent way for the average person to help protect pollinators. And it is! However, as with anything in life, there can be downsides.

In many urban areas, populations of native plants remain on undeveloped or abandoned land, in parks or reserves, or simply as part of the developed landscape. Urban areas may also share borders with natural areas, the edges of which are particularly prone to invasions by non-native plants. Due to human activity and habitat fragmentation, many native plant populations are now threatened. Urban areas are home to the last remaining populations of some of these plants.

Concern for native plant populations in and around urban areas prompted researchers at University of Pittsburgh to review some of the impacts that urban pollinator gardens may have and to develop a “roadmap for research” going forward. Their report was published earlier this year in New Phytologist.

Planting a wildflower seed mix is a simple way to establish a pollinator garden, and such mixes are sold commercially for this purpose. Governmental and non-governmental organizations also issue recommendations for wildflower, pollinator, or meadow seed mixes. With this in mind, the researchers selected 30 seed mixes “targeted for urban settings in the northeastern or mid-Atlantic USA” to determine what species are being recommended for or commonly planted in pollinator gardens in this region. They also developed a “species impact index” to assess “the likelihood a species would impact remnant wild urban plant populations.”

A total of 230 species were represented in the 30 seed mixes. The researchers selected the 45 most common species for evaluation. Most of these species (75%) have generalized pollination systems, suggesting that there is potential for sharing pollinators with remnant native plants. Two-thirds of the species had native ranges that overlapped with the targeted region; however, the remaining one-third originated from Europe or western North America. The native species all had “generalized pollination systems, strong dispersal and colonization ability, and broad environmental tolerances,” all traits that could have “high impacts” either directly or indirectly on remnant native plants. Other species were found to have either high dispersal ability but low chance of survival or low dispersal ability but high chance of survival.

This led the researchers to conclude that “the majority of planted wildflower species have a high potential to interact with native species via pollinators but also have the ability to disperse and survive outside of the garden.” Sharing pollinators is especially likely due to super-generalists like the honeybee, which “utilizes flowers from many habitat types.” Considering this, the researchers outlined “four pollinator-mediated interactions that can affect remnant native plants and their communities,” including how these interactions can be exacerbated when wildflower species escape gardens and invade remnant plant communities.

photo credit: wikimedia commons

The first interaction involves the quantity of pollinator visits. The concern is that native plants may be “outcompeted for pollinators” due to the “dense, high-resource displays” of pollinator gardens. Whether pollinator visits will increase or decrease depends on many things, including the location of the gardens and their proximity to native plant communities. Pollinator sharing between the two has been observed; however, “the consequences of this for effective pollination of natives are not yet understood.”

The second interaction involves the quality of pollinator visits. Because pollinators are shared between native plant communities and pollinator gardens, there is a risk that the pollen from one species will be transferred to another species. High quantities of this “heterospecific pollen” can result in reduced seed production. “Low-quality pollination in terms of heterospecific pollen from wildflower plantings may be especially detrimental for wild remnant species.”

The third interaction involves gene flow between pollinator gardens and native plant communities. Pollen that is transferred from closely related species (or even individuals of the same species but from a different location) can have undesired consequences. In some cases, it can increase genetic variation and help address problems associated with inbreeding depression. In other cases, it can introduce traits that are detrimental to native plant populations, particularly traits that disrupt adaptations that are beneficial to surviving in urban environments, like seed dispersal and flowering time. Whether gene flow between the two groups will be positive or negative is difficult to predict, and “the likelihood of genetic extinction versus genetic rescue will depend on remnant population size, genetic diversity, and degree of urban adaptation relative to the planted wildflowers.”

The fourth interaction involves pathogen transmission via shared pollinators. “Both bacterial and viral pathogens can be transmitted via pollen, and bacterial pathogens can be passed from one pollinator to another.” In this way, pollinators can act as “hubs for pathogen exchange,” which is especially concerning when the diseases being transmitted are ones for which the native plants have not adapted defenses.

photo credit: wikimedia commons

All of these interactions become more direct once wildflowers escape gardens and establish themselves among the native plants. And because the species in wildflower seed mixes are selected for their tolerance of urban conditions, “they may be particularly strong competitors with wild remnant populations,” outcompeting them for space and resources. On the other hand, the authors note that, depending on the species, they may also “provide biotic resistance to more noxious invaders.”

All of these interactions require further investigation. In their conclusion, the authors affirm, “While there is a clear potential for positive effects of urban wildflower plantings on remnant plant biodiversity, there is also a strong likelihood for unintended consequences.” They then suggest future research topics that will help us answer many of these questions. In the meantime, pollinator gardens should not be discouraged, but the plants (and their origins) should be carefully considered. One place to start is with wildflower seed mixes, which can be ‘fine-tuned’ so that they benefit our urban pollinators as well as our remnant native plants. Read more about plant selection for pollinators here.

Drought Tolerant Plants: Water Conservation Landscape at Idaho Botanical Garden

Demonstration gardens are one of the best places to learn about drought tolerant plants that are appropriate for your region. Such gardens not only help you decide which species you should plant, but also show you what the plants look like at maturity, what they are doing at any given time of year, and how to organize them (or how not to organize them, depending on the quality of the garden) in an aesthetically pleasing way. A couple of years ago, I explored the Water Efficient Garden at the Idaho State Capitol Building. This year I visited the Water Conservation Landscape at Idaho Botanical Garden in Boise, Idaho.

The Water Conservation Landscape is planted on a large L-shaped berm on the edge of Idaho Botanical Garden’s property. It is the first thing that visitors to the garden see, before they reach the parking area and the front gate. It is nearly a decade old, so the majority of the plants are well established and in their prime. Because the garden is so visible, year-round interest is important. This imperative has been achieved thanks to thoughtful plant selection and design.

This demonstration garden came about thanks to a partnership between Idaho Botanical Garden and several other organizations, including the water company, sprinkler supply companies, and a landscape designer. An interpretive sign is installed at one end of the garden describing the benefits of using regionally appropriate plants to create beautiful drought tolerant landscapes. If you ever find yourself in the Boise area, this is a garden well worth your visit. In the meantime, here are a few photos as it appeared in 2017.

February 2017

bluebeard (Caryopteris incana ‘Jason’) – February 2017

Sedum spurium ‘Dragon’s Blood – March 2017

winter heath (Erica x darleyensis ‘Kramer’s Red’) – March 2017

May 2017

avens (Geum x hybrida ‘Totally Tangerine’) – May 2017

July 2017

American cranberrybush (Viburnum opulus var. americanum ‘Wentworth’) – July 2017

Fremont’s evening primrose (Oenothera macrocarpa ssp. fremontii ‘Shimmer’) – July 2017

Fremont’s evening primrose (Oenothera macrocarpa ssp. fremontii ‘Shimmer’) – July 2017

August 2017

cheddar pink (Dianthus gratianopolitanus ‘Firewitch’) – August 2017

smoketree (Cotinus coggyria ‘Royal Purple’) – August 2017

gray lavender cotton (Santolina chamaecyparissus) – September 2017

showy stonecrop (Hylotelephium telephium ‘Matrona’) – September 2017

showy stonecrop (Hylotelephium telephium ‘Matrona’) – September 2017

Adam’s needle (Yucca filamentosa ‘Color Guard’) – October 2017

fragrant sumac (Rhus aromatica ‘Gro-Low’) – October 2017

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Book Review: Grow Curious

In the early 2000’s when I was really getting excited about learning how to garden, one of the first resources I turned to was a website called You Grow Girl by Gayla Trail. I probably saw it mentioned in a zine about gardening. Something about it felt very punk rock. Trail’s site was different than other resources, and it spoke to the anti-authoritarian, non-conformist in me. Reading through the About page today, Trail’s punk rock spirit hasn’t waned, and I can see why her site appealed to me.

Now with well over two decades of gardening experience to draw from, Trail continues to run her site, has written five books (including one called You Grow Girl), and her “contemporary, laid-back approach” to gardening remains essentially the same. In her words, she “places equal importance on environmentalism, style, affordability, art, and humour.” Her “aim has always been to promote exploration, excitement, and a d.i.y approach to growing plants without the restrictions of traditional ideas about gardening.” We share these sentiments, which is why when I learned of her most recent book, Grow Curious, I knew I needed to read it.

Grow Curious by Gayla Trail accompanied by a pressed leaf from Trail’s garden.

Grow Curious is an activity book for gardeners of all ages, backgrounds, and skill levels. It diverges from most books about gardening in that it is not a how-to or a what-to-plant-where guide. It is instructional, but only in ways that are less about getting our chores done and more about helping us explore our gardens in order to see them in a new light and open our eyes to the remarkable world that is right outside our door – a world often overlooked because we have work to do. Trail’s book is also meant to reinvigorate any of us that may be a bit disillusioned by the act of gardening – having misplaced our spark along the way, lost in the drudgery of it all. It’s about stopping for a minute, looking around, and seeing things we maybe haven’t noticed before but that have been there all along.

Because Grow Curious is a compilation of garden activities (“an invitation to play”) interspersed with prose, there is no need to consume it chronologically. Activities can be done in order or chosen at random. They can be skipped altogether or done at different times of the year. The book, however, is organized by season, starting in spring and ending in winter. In this way, the story of the birth and death of the garden is told, a polarity that Trail reflects on throughout the book. In the introduction to “Fall,” she writes of the growing season coming to a close and the garden becoming “a scene of decay.” The garden’s death can help us come to terms with other deaths, including our own. On a brighter side, the return of spring can bring a newfound sense of “hope, transformation, and optimism;” along with “the energy of renewal.”

Botanical rubbings – one of dozens of creative, garden activities found in Grow Curious by Gayla Trail

The bulk of this book is a series of activities that are meant to, as the subtitle proclaims, “cultivate joy, wonder, and discovery in your garden.” In general, the instructions are minimal – a short paragraph or two; a single sentence followed by a list of things to observe or do. In this way, you have the freedom to explore and make things up as you go, without worrying about rules or whether or not you are doing it right. Activities include touching an insect, observing the shapes of leaves and stems, smelling soil, taking pictures from new and unusual angles, visiting your garden in the dead of night, et cetera. Some activities are more involved, like raising a caterpillar or researching something to death. Other activities require little effort, like pulling up some plants to see what color their roots are or tasting an edible plant part that you have never tasted before. To facilitate advanced exploration, many of the activities include ideas or ways to “Go Further.”

Among the pages of activities are Trail’s musings on gardening and life (as it relates to gardening), and I found these to be equally intriguing.  Like her thoughts on fear and insecurity: “I was inexperienced and uncertain, full of my own fears and excuses.” And her “balanced” view on pests in the garden: “Since our insect partners often depend on the so-called bad guys, it turns out that a balanced garden needs both.” Her encouragement to observe the differences between wild plants and weeds that grow within and beyond the borders of our gardens, and her plea for us to “invite wildness” in, noting the “knotty labyrinth” that exists between “wild” and “cultivated” – “social constructs that we place in opposition to each other.”

Orange roots of California poppy (Eschscholzia californica). “As you’re digging up, moving around, and planting out new crops, trees, bushes, and perennials this fall, take note of plants that have colourful roots.” — Gayla Trail

If you have been following Awkward Botany for a while, you can probably see why this book is right up my alley. If you enjoy reading Awkward Botany, this book should be right up your alley, too.

When Sunflowers Follow the Sun

Tropisms are widely studied biological phenomena that involve the growth of an organism in response to environmental stimuli. Phototropism is the growth and development of plants in response to light. Heliotropism, a specific form of phototropism, describes growth in response to the sun. Discussions of heliotropism frequently include sunflowers and their ability to “track the sun.” This conjures up images of a field of sunflowers in full bloom following the sun across the sky. However cool this might sound, it simply doesn’t happen. Young sunflowers, before they bloom, track the sun. At maturity and in bloom, the plants hold still.

What is happening in these plants is still pretty cool though, and a report published in an August 2016 issue of Science sheds some light on the heliotropic movements of young sunflowers. They begin the morning facing east. As the sun progresses across the sky, the plants follow, ending the evening facing west. Over night, they reorient themselves to face east again. As they reach maturity, this movement slows, and most of the flowers bloom facing east. Over a series of experiments, researchers were able to determine the cellular and genetic mechanisms involved in this spectacular instance of solar tracking.

Helianthus annuus (common sunflower) is a native of North America, sharing this distinction with dozens of other members of this recognizable genus. It is commonly cultivated for its edible seeds (and the oil produced from them) as well as for its ornamental value. It is a highly variable species and hybridizes readily. Wild populations often cross with cultivated ones, and in many instances the common sunflower is considered a pesky weed. Whether crop, wildflower, or weed, its phototropic movements are easy to detect, making it an excellent subject of study.

Researchers began by tying plants to stakes so that they couldn’t move. Other plants were grown in pots and turned to face west in the morning. The growth of these plants was significantly stunted compared to plants that were not manipulated in these ways, suggesting that solar tracking promotes growth.

The researchers wondered if a circadian system was involved in the movements, and so they took sunflowers that had been growing in pots in a field and placed them indoors beneath a fixed overhead light source. For several days, the plants continued their east to west and back again movements. Over time, the movements became less detectable. This and other experiments led the researchers to conclude that a “circadian clock guides solar tracking in sunflowers.”

Another series of experiments helped the researchers determine what was happening at a cellular level that was causing the eastern side of the stem to grow during the day and the western side to grow during the night. Gene expression and growth hormone levels differed on either side of the stem depending on what time of day it was. In an online article published by University of California Berkeley, Andy Fell summarizes the findings: “[T]here appear to be two growth mechanisms at work in the sunflower stem. The first sets a basic rate of growth for the plant, based on available light. The second, controlled by the circadian clock and influenced by the direction of light, causes the stem to grow more on one side than another, and therefore sway east to west during the day.”

The researchers observed that as the plants reach maturity, they move towards the west less and less. This results in most of the flowers opening in an eastward facing direction. This led them to ask if this behavior offers any sort of ecological advantage. Because flowers are warmer when they are facing the sun, they wondered if they might see an increase in pollinator visits during morning hours on flowers facing east versus those facing west. Indeed, they did: “pollinators visited east-facing heads fivefold more often than west-facing heads.” When west-facing flowers where warmed with a heater in the morning, they received more pollinator visits than west-facing flowers that were not artificially warmed, “albeit [still] fewer than east-facing flowers.” However, increased pollinator visits may be only part of the story, so further investigations are necessary.

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I’m writing a book about weeds, and you can help. For more information, check out my Weeds Poll.

Summer of Weeds: Eating Purslane

If it wasn’t so prolific and persistent, purslane would probably be a welcome guest in our vegetable gardens and edible landscapes. Easily among the most nutritious and versatile of the edible weeds, Portulaca oleracea is an annoyingly abundant annual that has inserted itself into garden beds and croplands in temperate climates across the globe. Thought to have originated in India or somewhere in Eurasia, purslane invaded North America long before Europeans did and has been naturalized across much of the continent for hundreds of years.

common purslane (Portulaca oleracea)

There are over 100 known species in the genus Portulaca, the only genus in the family Portulacaceae (otherwise known as the purslane family). Common purslane is a succulent plant with paddle- or teardrop-shaped leaves that generally grows low to the ground, forming a thick mat. It reaches for the sky when grown in shade or when competing with other plants for space. It produces little, yellow flowers that only open in bright sun and are typically self-pollinated. A small capsule containing dozens of tiny, black seeds quickly follows each flower. Each plant can produce tens of thousands of seeds, which remain viable for around 40 years.

Attempts to remove purslane by cultivation may only aid its survival. Broken pieces of the plant can take root in the soil, and uprooted plants can re-root if they are in contact with soil. Stirring up the ground brings to the surface seeds from purslane’s extensive seed bank. These freshly exposed seeds can then germinate, taking advantage of disturbance and open space. For all these reasons and more, John Eastman writes in The Book of Field and Roadside: “Purslane knows how to live and linger.”

The ever-urban and ever-common purslane.

The seeds of purslane germinate in late spring and throughout the summer when the soil has reached at least 75 – 80° Fahrenheit. It is adapted to high heat and dry soils. In order to conserve water, it switches to CAM photosynthesis when conditions are particularly hot and dry. In this photosynthetic pathway, carbon dioxide is stored as malic acid during the night and then converted back during the day. This means that, when it comes to eating purslane, the flavor changes depending on when the plant is harvested. In The Wild Wisdom of Weeds, Katrina Blair discusses this phenomenon: “In the morning purslane leaves contain as much as ten times more malic acid, making them very sour tasting. If you prefer a milder tasting purslane, harvest your greens in late afternoon and if you want more zing to your recipes, gather the leaves at dawn.”

Speaking of eating purslane, if all the claims are to be trusted, there may not be a more nutritious weed. In A Feast of Weeds, Luigi Ballerina calls it “a health bomb” because “it contains more omega-3 fatty acids than almost any other green, not to mention vitamins A, B, and C and beta carotene.” Blair calls it “one of the most nutritious plants on Earth,” and goes on to sing praises about its richness in dietary fiber, vitamins, minerals, protein, etc. Funnily enough, in describing the health benefits of purslane, Ballerina also quotes ancient sources claiming that “purslane calms sexual excitement.” Apparently it not only “eliminate[s] sensual dreams, but if used too much, it often extinguishes all ardor and even the capacity to procreate.”

With that caveat in mind, I tried it anyway. I had eaten it before, but nothing more than a leaf here and there and once in a green salad. I picked two recipes to try: Walnut Purslane Coleslaw from The Wild Wisdom of Weeds and Potatoes and Purslane from A Feast of Weeds. I’m generally a big fan of coleslaw, but for whatever reason I found this recipe to be a little bland. It was missing something, but I couldn’t put my finger on it. The purslane seemed to add a vague slimy-ness to it, which it will do on account of its mucilaginous nature.

Walnut Purslane Coleslaw

The Potatoes and Purslane recipe involved cooking the purslane. I enjoyed the finished product both hot and cold. The purslane added a sort of lemon-y spinach flavor. Those who tried it with me also liked it. The potato recipe was made with purslane that had been harvested in the morning, which may explain the strong lemon-y flavor. The coleslaw was made with purslane harvested in late afternoon, which may explain its blandness. I will have to try it the other way around for comparison. Purslane recipes abound in books and on the internet; browsing through them, I am intrigued enough to consider trying others. I think I’ll start with pickled purslane, purslane pesto, and perhaps, purslane sauerkraut.

Potatoes and Purslane

More Resources:

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Do you have a favorite purslane recipe? Share it in the comment section below.

Introducing the Summer of Weeds

I spent the first five months of this year posting almost exclusively about invasive species. There is still plenty more to say on the topic, and I’m sure I will get back to that. However, it is time now to dive into the topic that I really want to explore. Weeds.

There is definitely crossover between the two topics – many weeds are invasive species – but there are clear distinctions, too. Oftentimes, weeds as a category of plants are unfairly and unjustly lumped under the title “invasive,” but any plant can be a weed at any moment in time if a human says so. That’s the difference. A plant does not have to prove that it is causing any sort of ecological or economic damage to be called a “weed;” it just has to be growing where a human doesn’t want it to. Yet, too quickly a plant “out of place” is cursed at using words like “invasive” or “noxious” regardless of its origin or behavior. I know I’m being overly semantic about this, but it seems unfair (and incorrect) to lump any and all plants that are bothering us for whatever reason into categories that have legal definitions.

If you can’t already tell, I am obsessed with weeds. It’s a topic I have been thinking about fairly consistently for much of my adult life. For one thing, as part of my career I spend a huge portion of my time killing and controlling weeds. I comprehend fully the visceral reaction of seeing a garden overcome by weeds – the vile thoughts one can have towards a group of plants that are soiling what could otherwise be a beautiful landscape – and I know very well the backbreaking work and countless hours that go into removing uninvited plants (cursing the intruders along the way). I get why weeds are a problem, and I understand why they are a subject of so much vitriol. Yet, over the years I have developed a respect – even a love – for weeds (despite the fact that I still must remove them and that removing them continues to be an overwhelming task).

Unwanted plants have been following us around and getting in our way for millenia. Essentially, we are partners in crime. We intentionally and unintentionally bring plants from various parts of the world on our travels, and through disturbance we create conditions where introduced plants can settle in and thrive. Over time, some once beloved plants grow out of favor and transition from desirable to weedy. As our cycles of disturbance continue, we give early successional, opportunistic plant species a chance to perpetuate themselves, guaranteeing that we will keep such “weeds” with us forever. We reap what we sow; even though we generally don’t plant weeds on purpose, other actions ensure that they will be our constant companions.

The importance of weed control goes beyond the aesthetic. In horticulture and agriculture, weeds compete with crops for light, space, water, and nutrients. They also harbor pests and diseases, and their seeds can contaminate crops. In pastures and rangelands, some weeds poison livestock. Certain weeds are harmful to people, too. Other weeds are simply disruptive – getting tangled up in machinery, damaging infrastructure, blocking our vision along roadways, and even giving cyclists flat tires. Apart from all that, even if all weeds did was make our gardens look unsightly, I imagine we would still be pretty angry with them.

I am interested in weeds wherever they are, but the weeds that fascinate me the most are those that thrive in urban environments. Not necessarily the weeds in our yards, but the weeds that have escaped our fences and property lines; the ones in the margins. We see them in abandoned lots, along roadways, near irrigation channels, and in other neglected spaces. They pop up in the cracks of sidewalks, on rooftops, in the middle of decaying buildings, and anywhere else that people haven’t paid attention to in a while. Urban areas have, for the most part, been scraped of their native flora. Introduced species move in to fill that void. As Richard Mabey writes in his book about weeds, these plants “insinuate the idea of wild nature into places otherwise quite shorn of it;” they are “the very essence of wildness.” Novel ecosystems, like those created by urbanization and human development, are with us whether we like it or not. There is a “wildness” to them that is unlike other cultivated and manicured areas maintained by humans. These urban wild places are worth a closer look.

So, what is the Summer of Weeds?

Put simply, it’s an exploration of weeds. Throughout the summer I will be profiling some of the weeds I come across in my daily life. I will include photos, a brief description, and some interesting facts about each species. I will also include quotes about weeds from various sources, as well as videos, links, resources, and whatever else I come across that seems worth sharing. I hope you enjoy it. If you have anything to add along the way – specifically any personal thoughts or stories to share about weeds – please do. You can contact me via the usual ways: in the comment section below, through the Contact page, or on Twitter, Tumblr, Facebook, or Instagram. Happy Summer!