Sarah and Dan Barron
No matter your garden, or gardening experience, planting native species can be aesthetically pleasing while contributing to local biodiversity. To some, the “native” gardening journey may seem daunting. We’re writing to provide you with valuable resources that we hope will turn hesitation or fear into enjoyment and excitement.
Between the two of us, we have experience working in the native nursery trade, as well as seed collection and bare root propagation. We’ve also had our own experiences with urban plantings, such as converting a fence-to-fence lawn into an urban lot with over 80 native species.
We’ll walk you through five key areas to get you started on your journey; why you should consider planting natives over non-natives, what to expect through the process, options for preparing your site, choosing species, and finally, methods of planting.
Let’s start with the most overarching question:
why plant native species?
In truth, this article would be never-ending if we addressed this question solely, but here are a few solid reasons to begin with.
Biodiversity: No matter how much land you’re working with, planting native species is an assured way to bring biodiversity to your area, which, in turn, helps the greater environment. When you put a native plant in the soil, even if it’s just one, you’re bringing more than just plant diversity.
Even our small yard in the middle of La Crosse, Wisconsin, has attracted foxes, opossums, warblers and on occasion a Wood Thrush. We’ve also witnessed steady increases in the diversity of solitary bees, beetles and butterflies. There are countless insect species reliant on native plants and many more bird species dependent on those insects, especially when raising their young.
Whether it be goldfinches dining on the seeds of a mature Silphium perfoliatum (Cup Plant), monarch butterflies on milkweed (Asclepias spp.) or bumblebees on Monarda fistulosa (Wild Bergamot), a minor inclusion of native plants can have a monumental impact on the local environment. Encouraging biodiversity also contributes to your own satisfaction; the ability to look out your window or stroll around the yard, always with a possibility of seeing something new.
Inputs (or the lack of): We’re struck by the supplemental efforts that many conventional ornamental varieties require, which may include the application of concentrated fertilizers. Generally native plants require no input of nutrients – aside from the occasional inclusion of compost or mulch (don’t rake those leaves to the curb!). The application of highly concentrated fertilizers will often only benefit fast-growing annual weeds.
Many non-native ornamental varieties are prone to insect damage and pathogens. This is primarily due to the fact that these (non-native) ornamental species evolved in a different part of the world, with a different array of insect herbivores. When growing species native to your region, you can be assured that most of those plants have had thousands of years to “work out” many of the insect and fungal issues that cause some gardeners to turn to pesticides and fungicides. While natives are not exempt from insect predation and the adverse affects of pathogens, you will find that occurrences are less problematic. In fact, predation from native insects might be part of your goal all along (host species!).
Resiliency: Being a resident of the midwest, you can understand how variable and harsh seasonal weather can be. Plant species that have endured the extremes of summer and winter for thousands of generations are best able to thrive in, or at least endure increasingly adverse growing conditions. For example, many shortgrass prairie species have evolved to conserve water. You’ll see this most often in plants with a dense covering of hairs and/or deep tap roots.
Carbon Sequestration: Complex or deeply rooted native perennials sequester massive amounts of carbon from our atmosphere. The resulting richness in soil is one reason why nearly all of our tallgrass prairies were plowed under and converted into farmland.
Education: Lastly, we’ll note that whether you’re a beginner at observing the natural world, or a seasoned naturalist, you’ll find that having native plants so close to home provides endless educational opportunities. Having natives plants a few steps from our front door helped us learn identifying factors through various plant life stages, not to mention the ever-interesting insect species that frequent those native plants.
Now that you’re familiar with some of the benefits of planting natives, let’s discuss what to expect.
As gardeners of native plants, you’re creating small habitats. And with that, comes the unpredictability of nature. We’ve planted, dare we say, hundreds of roots and seeds that never sprang up. Or, they did, only years after expected to do so, which then had to compete with hastily chosen (back-up) species over the same area. If your plan is to maintain order of the natural world, you may achieve that goal partially, but never fully. The natural world is not a well ordered English garden. Having said that, planting natives doesn’t have to mean you’ll have a “wild” looking yard. As with all gardening, the visual aesthetic is ultimately dependent on the work of the gardener.
Being seed collectors and growers of 1,000’s of plants per year, we are frequently faced with an abundance of “seed cleanings” and roots that are too small to sell. In our case, the result was a series of “experimental” beds that have been affectionately referred to as our “urban chaos prairie”. In reality, the “chaos” is diverse and ever-changing, more resembling a reconstructed prairie than an intentional planting. Species that worked well in this situation were typically similar in habit, or at least complimentary in regarding to growing season – Dalea purpurea (Purple Prairie Clover), Sisyrinchium campestre (Prairie Blue-eyed Grass), Asclepias verticillata (Whorled Milkweed) and annual Chamaecrista fasciculata (Partridge Pea) provided full season interest and forage for insects in a dry, sunny corner of the yard.
Conversely, we’ve had wonderful success with native plants in areas that needed to appear “landscaped”, such as the front of our house. In these situations it’s really important to understand the habits of the plants you choose. These habits can be exploited to support a particular aesthetic or need.
For instance, clump-forming grasses, such as Andropogon gerardii (Big Bluestem) and Sporobolus heterolepis (Prairie Dropseed), and sedges, such as Carex radiata (Eastern Star Sedge) and Carex sprengelii (Sprengel’s Sedge), make excellent borders – with shorter species in the front and taller bringing up the back. Taprooted species like Silphium laciniatum (Compass Plant) will tend to stay in place, while its rhizomatous cousin Silphium perfoliatum (Cup Plant) is eager to form colonies (it also makes a great seasonal privacy fence). Baptisias such as Baptisia lactea (White Wild Indigo) make excellent specimen plants. A combination of mulching around smaller areas with “well behaved” species, like Echinacea pallida (Pale Purple Coneflower), while promoting more aggressive species like Monarda punctata (Spotted Horsemint) in larger areas can provide different textures, while minimizing long-term cost and labor.
It’s also important to recognize that natives have aesthetic interest often before and after bloom times. So, when choosing species, cast a wider net than just how the flower looks. A few shining examples include Geum triflorum (Prairie Smoke) with its billowing pink seed head and seemingly evergreen basal leaves, or the lush foliage of Polemonium reptans (Spreading Jacob’s Ladder). Sometimes dormant foliage is the showiest, such as Schizachyrium scoparium (Little Bluestem) and Lespedeza capitata (Round-headed Bush Clover), both providing long-lasting winter interest.
Now we’ll cover a few options for preparing your site. We should note that we’ve decided to abstain from the use of herbicide, so all of these options are “mechanical”.
In well established lawn, where annual weeds have been mostly controlled via mowing, the physical act of “de-sodding” can be very effective. While mainly practical for smaller areas, de-sodding removes short-rooted sod below the root (generally around 2”) along with many weed seeds that rest dormant in the top layer of soil. There are a variety of de-sodding methods available, including manual and gas powered sod cutters that can be rented from many hardware stores. The most simple (and cheap) way is to vertically “slice” a contour of your future bed with a sharp spade. The contour line will permit sliding the spade horizontally beneath the root layer, severing the roots and resulting in “mats” of sod that can be rolled up and moved off of your garden site. This method is low-cost, but labor heavy. In our case, we ran out of uses for the de-sodded layer (there are only so many low spots in a yard to fill), so we piled it up in a long row (upside down) and covered it with repurposed permeable landscape cloth. This eventually became a nice “mound” for gardening cucumbers, squash and watermelon.
Smothering is an excellent solution for reducing competition on small and medium-sized areas. It can also be the least labor intensive method, but that will mean waiting a full season or more to ensure that smothering has done the trick in reducing or eliminating the pressure of existing vegetation. There are different takes on this method, but almost any large object that blocks light can be used to smother an area (plywood, large tarps, cardboard). For large areas (frequently used by commercial growers), rolls of water permeable but light-blocking landscape cloth can be rolled out and secured with 6” sod staples. This method is highly effective and the plastic is re-usable for many years. Still, the plastic can be expensive – and will eventually contribute to the waste stream.
Solarizing has been promoted by some organizations, such as the Xerces Society. This method is similar to smothering, as the method covers an area with a plastic substrate, but in this case the plastic is clear, allowing light to permeate. The goal is to encourage heating of the top soil layer – which in theory kills vegetative growth and existing weed seeds within that stratum. This method is more expensive than smothering because a high-grade (UV stable) transparent plastic, such as greenhouse covering is needed (though recycled options may be available for free). Also, all of the edges must be buried in soil to form a tight seal that “captures” heat.
Mulching can be an excellent method to control existing vegetation. Mulching is essentially “smothering” with organic, biodegradable materials. We’ve found that raking our fall leaves into simple enclosures of chicken wire (which prevent the leaves from blowing away) provide an ideal area for planting seed or plugs. By spring the leaves (even 20”+) will compress into a thin layer, often resembling rich compost. We’ve had success with covering this “leaf layer” with growing medium and directly sowing seeds. Some have also experimented with piling sand or wood chips on top of cardboard “mulch”. The resulting barrier between existing vegetation provides at least a season of coverage and may promote direct sowing of seed mixes. This has been proven effective when layers of sand are coupled with the planting of seed mixes containing shortgrass prairie species.
If planting into a larger areas, say 1,000 square/feet or more, you may want to look at the process a bit differently. While not the scope of this article, we will note that many large areas have been successfully over-seeded with native plants without the use of herbicides. This method, which mostly pertains to prairie reconstructions, relies on periodical mowing to suppress fast-growing weedy competition. As the characteristics of a garden or planting are variable, so too are the methods required to propagate and manage native plantings.
Now let’s dive deeper into the fun part – choosing species!
We’ve covered some potential options throughout this article, but there is a lot to consider when starting out. How do you ensure the plant is actually native? Or maybe the plant is native to the North America, but not to your region – or perhaps there are species that are “native” but may not work well for your site? One obvious method is to visit a local native remnant that mirrors your site, to see what is growing. Still, seasonal variability and experience may prove daunting. Also, many state and federal natural areas provide species lists, which can be used to guide your site plan. Finally, most reputable native plant nurseries may provide this information online, or via consultation. The important factor is to ask questions (is this species a cultivar, is it native to my areas, etc).
If ordering from a nursery, double check the botanical name on the species. Word of warning – never buy plants or seed that don’t list the botanical name. Some species, like Monarda fistulosa (Wild Bergamot), are often found in catalogues, but may actually be cultivars of a native species (nativars). Be wary of “nativars” which are typically plants bred for human appeal, while ignoring ecological impacts. These commercial hybrids usually have names like “Rudbeckia Cherry Brandy” or “Sombrero® Salsa Red Echinacea” (notice the “®”). As with all plants, you’ll also want to pay attention to necessary growing conditions, like sun exposure and soil moisture.
When planning small garden areas, some sources suggest avoiding native plants deemed as “aggressive”. We’d like to present a case for planting those exact species. Our small gardens had several “aggressive” species, and they were some of our favorite garden areas. Aggressive (rhizomatous) species are particularly handy for gardeners who have tight budgets, or have difficult growing conditions. Sure, our Anemone canadensis (Canada anemone) found its way between our brick pathways. But, so did the quack grass and annual weeds. Our view is that if an area requires the removal (management) of “weedy” plants, it would be better to cull native species, instead of non-native varieties. A bonus of culling native weedy species, is that they can be transplanted somewhere else or given away! If in doubt, do a little homework Many gardeners chose aggressive non-native plants that we deem much more of a nuisance. Invasive species such as Japanese barberry, European buckthorn and multifora rose should be avoided at all cost. Of course, every gardeners circumstances are different, but we hope to provide some support should you feel convicted to choose an “aggressive” native.
Finally, we’ll quickly cover a few methods of planting.
First, if you need “landscaped” results, then transplanting “dormant bare roots” or live “plugs” will be the way to go. Bare root plants, which are already 1-2 years old, will frequently flower within the same season of transplanting, though results will vary by species and growing condition. Commercial bare root plants are usually grown in beds, without inputs. If purchasing bare roots, be careful to ensure that they were propagated for sale and never wild dug.
Plugs are typically grown quickly in a greenhouse and pushed to a sellable size with heat and inputs. Most plants sold as plugs are in their first growing season, making them less likely to bloom that year. Still, plugs are a good way to get plants in the ground, especially given their small uniform size and lower cost.
If purchasing live plants, you should note that many native plant nurseries start marketing their spring offerings as early as January. So, if you’re hoping to purchase live plants, you’ll want to finalize those orders by mid-February.
Alternatively, you might consider growing “plugs” or “roots” yourself. Really, this is the most rewarding and cost-effective method of gardening with natives. Seed packets can be purchased for a few dollars, or if done carefully, common species can be collected from roadsides. If you’re hoping to maintain local genetics, roadside collection is probably going to be your best option. Do your research before wild collecting seed. Never collect from managed wildlife areas or preserves, and limit your collection to less than 20% of a population.
Generally speaking, most native plant seeds will require some period of pre-treatment before germination can occur. The most common treatment is “cold moist stratification” which breaks a seeds dormancy by mimicking the effects of winter conditions on a particular seed. A few common examples include Amorpha canescens (Lead Plant), which requires 10 days of cold moist stratification, Asclepias incarnata (Swamp Milkweed) which requires 30 days of cold moist stratification (most Asclepias species require 30 days), or Echinacea pallida (Pale Purple Coneflower) which requires 90 days of cold moist stratification. Conversely, some species don’t require any pretreatment at all, such as Pycnanthemum virginianum (Virginia Mountain Mint), though these can be slow to germinate. Plants started from seed can usually be dug after 1-2 seasons. You’ll want to dig roots while the plant is dormant, early-fall or early-spring, before transplanting them to the preferred location.
If you have a large area and a few years, then a seed mix (or mixes) may be the way to go. To successfully introduce a native seed mix, you’ll do best with 1-2 years of “site prep” (suppression of existing vegetation). If you have no expectations and a fairly stable area, like a frequently mowed hay field of smooth brome, simply overseeding for several years and following-up with occasional mowing (and burning) will probably result in the eventual growth and success of some native plants – although this method will likely take many years.
Finally, combining all of the above methods might be an excellent and appropriate path forward as well. For example, using plugs or bare roots selectively around high visibility areas, such as walkways or building entrances, will ensure a more intentional aesthetic with blooming very likely in the first year or two. Meanwhile, you can utilize seed mixes for larger areas with less foot traffic and less pressure to achieve fast results.
It’s impossible to include everything there is to know about native plant gardening – and we certainly don’t know everything! – but we hope this has left you with an ambition to integrate more nature in your life. And, when you’re challenged, connect with others who are also engaged with this endeavor. We, and other native plant gardeners, are usually happy to share in joys, concerns, or to help pass the time until the first buds open. •
Feel free to contact us with any questions, including species suggestions, propagation methods and trusted native plant nurseries.