Native "Weeds"
Many native "weeds" get an unfair bad rap—brushed off as unruly, undesirable, or just too ordinary. But what if we told you these overlooked plants are actually garden superheroes in disguise? It’s time to rethink what we dismiss and discover the hidden gems right under our noses!
A case for native “weeds”
There are a number of native “weeds” that folks will dismiss out of hand for being bad garden plants, seen as uncontrollable, or worse, ‘common’. But we're here to make a case for shifting our perspective around the plants our eyes skip past. There's a point in gardens where the rare collector gets all the appreciation- the harder to find a plant, the louder folks clamor over it. But just as keystone plants support 75%* of all native insect species because they are widespread and common, so too should we reconsider the average garden “weed”. There’s a time and a place for everything and we think we’ve found the time AND the place for our endemic “weeds”.
Most plants we call “weeds” are ruderal species. Ruderal comes from the Latin rudus meaning rubble and was first coined by Berlin ecologists when they observed life returning to the city after the destruction of WW2. In ecology, ruderals are the species that thrive in disturbance- also known as pioneer species. The toughest of the tough, they require no human intervention for their survival. What defines ruderal plant species is their high seed production, multiple pathways of reproduction, and the lack of specificity in nutrient requirements and soil types. They are on their own. Generally found in high disturbance sites, pioneer species exist in forgotten or overlooked areas along transportation lines, between building sites, or in abandoned lots. Ruderal plants act fast and colonize the open soil (sometimes not even soil - just a crack in the pavement). In ecology, these plant communities are called ‘urban spontaneous vegetation’. Research shows USV plant communities provide ecosystem services including erosion control, stream or river bank stabilization, excess nutrient absorption, temperature reduction, provide food and habitat for urban wildlife species, improved air and water quality, sound reduction, and even phytoremediation of contaminated soils. For all the benefits of urban spontaneous vegetation, what makes it extremely attractive as a landscape is the minimal input of maintenance resources. These plants don’t require traditional garden maintenance tasks like watering, fertilizing, deadheading, cutting back in winter, or dividing. They persist in the site for years, either in their perenniality or by self-seeding. However, the challenge lies in the human perception around these tough and resilient plant species. When present in the urban or suburban landscape, urban spontaneous vegetation is seen as a sign of derelict properties and neglect. No one would intentionally use such plants… would they?
Ah, but we are the dreamers. Where others see weeds, we see tough beauties who just need better PR and a good landscape framework providing context. Ruderal plants already exist in the harshest of human-modified environments. As the adage goes - don’t fight the site. Instead of thinking of these fast-growing species as common weeds that need to be managed or removed, why don’t we plant them on purpose instead? There are successful projects showcasing this path of leaning into what’s already present- two of the most famous being Landschaftspark Duisburg Nord in Germany and the High Line in New York City. Both weave in ruderal plants to their landscape designs but use strong framework and careful editing to cue to the public that this isn’t a neglected site but a reimagined, well-loved public space. In private gardens, look no further than Landcraft garden in New York in its creative use of mullein and joe pye weed in formal beds and ruin gardens. For the garden makers and the dreamers of dreams, maybe it’s time to bring some of these endemic ruderal species into rotation, give them context and place them in a site that needs their tough, colonizing characteristics. Every trait, even those sometimes regarded as negative, can be an asset when truly seen and understood.
Re-imagining our Native “weeds”
Andropogon virginicus | broomsedge
One of winter's joys is driving along the road and seeing open ground colonized by this upright, copper-gold tuft of grass. We’ve seen it opportunistically populate abandoned grocery store parking lots and be the first species when a hay field full of cool-season European grasses are left fallow. Sparrows strip the seedheads in winter and young turkeys hide amongst the clumps in spring. A short warm-season grass, typically growing 2-3’ tall and 1-2’ wide, broomsedge gets its name as the material to craft brooms in colonial times. Farmers grouse about broomsedge ability to self-sow but it’s a fine plant for erosion control, loves alkaline soils, handles soil compaction, and salt - all common pressures in urban planting situations. So, while a dairy farmer may not love Andropogon as a feed for cows in late summer, let’s not apply their use-case scenario and value judgement on a plant that has more than one application depending on site and situation. Andropogon virginicus has been maligned for too long - try it in mixed matrix planting style in a parking median and we bet folks will be whistling a different tune.
Panicum virgatum | switchgrass
The longest lived and most stable of the seven plants on this list, Panicum virgatum slowly fills in creating large clumps, but it can also sow around. It’s an anchor in the landscape, with a heft and gravity that holds the eye, while being airy and full of movement. Switchgrass is a plant of contradictions. We’ve seen it growing at the edge of a river, regularly flooded for weeks during king’s tide. We’ve seen it colonizing an abandoned chemical plant processing area, dry, barren soil that receives no additional irrigation. So yeah, we definitely think this plant can handle whatever you throw at it. In garden settings, we’ve seen Panicum virgatum used in a formal border at Olbrich Gardens, in a naturalistic planting in the High Line, as a foundation planting in Lewes Beach in Delaware, and part of a prairie mix in Illinois. Try it to hold soil in a landscape with hard rains, as a lush visual barrier in areas with drought periods - shoot, the only thing switchgrass can’t do is watch your kids.
Carex amphibola | creek sedge
Forget the mulch - try a sedge. Strappy leaves, robust semi-evergreen foliage, and a clumping habit are the key markers to this adaptable, overlooked native creek sedge. Frequently spotted along steep embankments along creeks and streams, it’s just as common along shady ditches catching agricultural runoff seeps. A hardworking substitute for ubiquitous Liriope, this plant isn’t flashy - it’s stable and tough. Go formal by using it to make formal edging in shade, plant as a green mulch under shrubs, or naturalistic as a base layer in a deciduous forest matrix. Carex amphibola is a low-growing, clumping sedge that works well as a shady lawn substitute that can be mowed once or twice a year. If allowed to go to seed, it will gently self-sow, filling the space.
Asclepias syriaca | common milkweed
Yeah, yeah, we know, common milkweed supports our endangered Monarch butterfly, recently listed on the Endangered Species list. It's more than that though. In fields infested with Johnson grass and bull thistle, common milkweed holds its own with rich heady scent and delicately mauve flowers. In areas where you need enduring plant material that will slither to find a place, common milkweed is a fighter. Tolerant of compacted clay soils, it grows in the wasted space in abandoned lots, neglected strips of agriculture fields, and along roadside all over North America. The rhizomes snake out, looking for an opportune spot, usually poking up in bare middle patches or along the edge. Common milkweed can be cut back mid-season to encourage a new flush of growth, good for the gardener and good for Monarchs that favor fresh season growth to lay their eggs on. (Read more about milkweed summer cutbacks here.)
Rudbeckia triloba | brown-eyed susan
Depending on the situation, this Rudbeckia species can be considered annual-ish, biennial, or a short-lived perennial. Its primary method of survival is its adept self-sowing in bare patches of earth. Brown-eyed susan is a wonderful mid to late season bloomer and works well for filling in planting voids as slower growing perennials like Baptisia or Andropogon are getting established. Native song birds adore the small seeds, sustaining them through long winters. For instant color, self-sowing spontaneity, and wildlife support, consider Rudbeckia triloba in your next planting project.
Achillea millefolium | yarrow
Considered a “cosmopolitan” weed, yarrow is found throughout the northern temperate hemisphere. With its widespread distribution, Achillea lets you know that it’s tough and can meet any challenge. For the best performance, grow Achillea in lean soils that dry out between waterings - whether it be sandy, rocky, or clay. We’ve seen it grown in gravel gardens to great effect, the infertile soil bringing about a stockier, stronger stem and the soft, silver-grey feathery foliage a striking contrast against the loose stone. For those not terribly interested in the soft cream flowers, the creeping foliage can be regularly mowed and used as a substitute for lawn when the lawn area has poor soil, full sun, and isn’t on irrigation. The more you mow, the more it encourages the plant to spread by short rhizomes and form a mat.
Eupatorium perfoliatum | common boneset
We once received an email from a customer about our boneset description on the website. The customer found that while we had a useful accounting of the plant, there was definitely a lack of stress placed on the floral aroma of this oft-overlooked perennial. To that customer, mea culpa, we beg your grace. For those who don’t know what we’re talking about, let us paint you a picture. Imagine a field of creamy-white flowering Eupatorium perfoliatum in late summer as the sunlight fades, the heat and humidity are high, the chirping of the crickets as your background orchestra, the musky, sweet floral scent filling the air. Once you experience it, the scent can trigger core memories for the rest of your life. With the strongest aroma at dusk, this plant demands to be planted en masse for full effect. A perfect companion to clumping warm-season grasses and other drought-tolerant, full-sun perennials, common boneset sows itself gently. The 3-4’ tall fine, olive-green foliage fades to upright, skeletal seed heads in winter.
The appeal of utilizing native ruderal species is their reduced maintenance inputs - you don’t need to water or feed them after the initial establishment phase. With the right plant selection, you don’t need to expend the finances and effort to amend the soil. What’s the trick, then? Well, it means to use ruderal species effectively, new forms of landscape maintenance will need to be employed, and more traditional procedures can be utilized for other areas. For best use of your ruderal species, aka “weeds”, here is what we suggest:
- Right plant, right place: choose the plant for the soil and light conditions, don’t modify the environment to meet your plant. Lean into what is already there and select a plant that tolerates the location’s amount of sun, rain, soil pH, drainage, and soil texture.
- Give it room: these plants like to run or self-sow. To embrace their rough-and-tumble nature, site ruderals in a place where their spread is an asset. Some situations naturally corral root or seed spread, i.e. planted in a cement enclosed parking median. Other ways one spread can be managed is by ensuring soil conditions are lean by not amending the soil with organic matter or by employing gravel gardens. Yet another way is to use ruderals as a pioneer plant in a large space where their spontaneous self-sowing creates a naturalistic massing effect, bringing seasonal drama.
- Plant care only when necessary: all of these plants can be left standing from year to year in more natural landscapes or can be cut back in late winter in more formal situations. They perform best when left up through the winter so give these plants their time to shine and hold back on the weed whacker for the season. You won’t need to worry about sprays or treatments - these plants will get along fine just on their own. While spray programs and mowing programs are a traditional part of landscape care, when one utilizes ruderal species, those tasks are no longer necessary.
- Know your ratios and when to edit—for applications with a light touch of ruderal species, approximate your ideal amount of self-sowing ruderal species when planning for your planting. As you plant your sweeps, dots, and drifts of plant material, know that the plants will move. For the longevity of the site, educate maintenance personnel about the approximate ratio of self-sowing ruderals that is anticipated for the maturity of the site and edit seedlings and their placement. Sometimes, that may mean weeding out plants if they are too great in number. Other times, which may mean transplanting seedlings that have migrated towards the edge of the landscape and redistributing them more evenly. For less intense maintenance, one can sprinkle seed collected in fall to areas where the plants have wandered away to encourage them to re-establish
Biggest tip? Give ruderals context or else they’re just “weeds”
What’s the difference between a horticultural gem and a weed? Where and how they’re planted. Taking things people think they know what they’re seeing and turning it on its head, subverting the traditional dogma is what ruderals in gardens are all about. Ground the plants in a context, part of a larger story, with intention and consideration. We love seeing the creativity out of Bondsville Mill Park and Garden or The Rail Park in Philadelphia. In Germany, this ruin garden created from a decrepit shipyard is an inspiration as is the Knepp Walled Garden in Britain. What do these places all have in common? Well, ok, yes, they’re all defunct places turned into gardens. But also, they’re places where pioneer species have already taken hold. Creative people envisioned, honed, and edited what already wanted to be there and enhanced it into a place that is beautiful. They kept the spirit of the place and gave it context as it transitioned from one part of its story into the next. Just as ruderals are a period of time in the ecological succession of a site, utilizing these plants can help subconsciously cue people into seeing the change and transition of an area, reimagining its purpose. If we can imagine a place can change, we can reimagine how we value and utilize commonly overlooked plants. So, yes, consider this our impassioned plea to please reconsider the “weeds”.
Sources:
Guo, P., Yu, F., Ren, Y., Liu, D., Li, J., Ouyang, Z., & Wang, X. (2018). Response of Ruderal Species Diversity to an Urban Environment: Implications for Conservation and Management. International Journal of Environmental Research and Public Health, 15(12), 2832. https://doi.org/10.3390/ijerph15122832
Turner, K., Lefler, L., & Freedman, B. (2005). Plant communities of selected urbanized areas of Halifax, Nova Scotia, Canada. Landscape and Urban Planning, 71(2-4), 191-206. https://doi.org/10.1016/j.landurbplan.2004.03.003
Wania, A., Kühn, I., & Klotz, S. (2006). Plant richness patterns in agricultural and urban landscapes in Central Germany—Spatial gradients of species richness. Landscape and Urban Planning, 75(1-2), 97-110. https://doi.org/10.1016/j.landurbplan.2004.12.006
Boanca, P., Dumitras, A., Singureanu, V., Doina, C. (2011) Ecological and Aesthetic Role of Spontaneous Flora in Urban Sustainable Landscapes Development. Plant Development, 18, 169-177. https://www.testing-grounds.com.au/wp-content/uploads/2023/08/Boanca-Ecological-and-Aesthetic-Role-of-Spontaneous-Flora-in-Urban-Sustainable-Landscape-Development.pdf
