Weeds of Boise: Railroad Tracks Between Kootenai Street and Overland Road

Walking along railroad tracks is a pretty cool feeling. It’s also a good place to look for weeds. Active railroad tracks are managed for optimum visibility and fire prevention, which means that trees and shrubs near the tracks are removed creating plenty of open space on either side. Open areas in full sun are ideal places for a wide variety of weed species to grow. Trains passing through can also be sources or dispersal agents of seeds, so there’s a chance that you may see things growing alongside railroad tracks that you don’t often see elsewhere. All this means that railroad tracks in urban areas are great locations to familiarize yourself with your city’s wild urban flora.

I visited a small section of railroad tracks between Kootenai Street and Overland Road in Boise. At one point, this was a pretty active railroad. Passenger trains once moved along these tracks, and the Boise Depot, which is less than a mile from this location, was one of several stops between Portland, OR and Salt Lake City, UT. Unfortunately, those services ended in 1997 and have yet to resume, despite continued support for bringing passenger rail back to the region. Still, freight trains pass by with some frequency.

Managing weeds along railroad tracks in urban areas can be tricky. There is little else in the way of vegetation to compete with the weeds. The tracks are also adjacent to parks, homes, schools, gardens, and other locations that make herbicide applications complicated. The species of weeds can also vary widely from one mile to the next, so management decisions must also vary. It’s especially important that the ballast directly beneath and on either side of the tracks is kept weed free in order to prevent fires and improve visibility. All of this and more makes weed control along railroad tracks one of the most challenging jobs around. Luckily, for someone that likes to look at weeds, it means there will always be interesting things to see near the tracks, including for example this colony of harvester ants that I came across while identifying weeds. I was happy to see that they were collecting the samaras of Siberian elm (Ulmus pumila), one of several weedy trees in the Treasure Valley.

What follows are a few images of some of the weeds I encountered along the railroad tracks between Kootenai Street and Overland Road, as well as a list of the weeds I was able to identify. The list will grow as I identify the mystery weeds and encounter others that I missed, as is the case with all posts in the Weeds of Boise series.

Virginia creeper (Parthenocissus quinquefolia)
blue mustard (Chorispora tenella)
cleavers (Galium aparine)
whitetop (Lepidium sp.)
Himalayan blackberry (Rubus bifrons)
bush honeysuckle (Lonicera sp.)
Siberian elm (Ulmus pumila)
English ivy (Hedera helix)
kochia seedlings (Bassia scoparia)
  • Arctium minus (common burdock)
  • Bassia scoparia (kochia)
  • Bromus diandrus (ripgut brome)
  • Bromus tectorum (cheatgrass)
  • Chorispora tenella (blue mustard)
  • Conium maculatum (poison hemlock)
  • Convolvulus arvensis (field bindweed)
  • Cirsium arvense (creeping thistle)
  • Dactylis glomerata (orchardgrass)
  • Descurainia sophia (flixweed)
  • Elaeagnus angustifolia (Russian olive)
  • Epilobium ciliatum (northern willowherb)
  • Equisetum sp. (horsetail)
  • Erodium cicutarium (redstem filaree)
  • Galium aparine (cleavers)
  • Hedera helix (English ivy)
  • Hordeum murinum (wild barley)
  • Lactuca serriola (prickly lettuce)
  • Lepidium sp. (whitetop)
  • Lonicera sp. (bush honeysuckle)
  • Parthenocissus quinquefolia (Virginia creeper)
  • Poa bulbosa (bulbous bluegrass)
  • Poa pratensis (Kentucky bluegrass)
  • Rubus bifrons (Himalayan blackberry)
  • Rumex crispus (curly dock)
  • Secale cereale (feral rye)
  • Taraxacum officinale (dandelion)
  • Ulmus pumila (Siberian elm)

Do you live near railroad tracks? What weeds are growing there, and do you feel as cool as I do when you walk the tracks?

Eating Weeds: Japanese Knotweed

When I first learned that Japanese knotweed was edible, I had my doubts. Sure, lots of plants may be edible, but are they really something you’d want to eat? I know Japanese knotweed as one of the most notorious weeds on the planet. Its destructive, relentless, and prolific nature has landed it on the world’s 100 worst invasive species list, right up there with black rats, Dutch elm disease, and killer algae. Having encountered a fair number of Japanese knotweed stands, the first thing to come to mind has never been, “that looks delicious.” Mature stalks stand as tall as 3 meters with broad, leathery leaves and hollow, bamboo-like stems. Their late summer flowers – a mess of tiny white florets on sprawling flower stalks – are a pollinator’s delight and favored by beekeepers for their abundant nectar. I don’t doubt that the honey produced from such an encounter is tasty, but the plant itself? I needed convincing.

Finally, I looked into it. I came across recipes of Japanese knotweed pickles and learned that it was the young, early emerging shoots that were sought after. That changed my perspective. Certainly you wouldn’t want to gnaw on a woody, 4 foot tall Japanese knotweed stalk, but the tender stems as they’re just beginning to re-emerge from the ground in the spring? Now those might be worth trying.

emerging stems of Japanese knotweed (Reynoutria japonica)

Japanese knotweed (Reynoutria japonica) was introduced to Europe from Japan in the 1800’s, arriving at Royal Botanic Gardens Kew by 1850. At that point, it was a prized ornamental. Its thick stems spotted with reds and purples, its broad, shiny leaves, and its showy flower heads all gave it garden appeal. It was also found to be useful for stabilizing hillsides and reducing erosion, honey production, and as a rhubarb substitute (it’s in the same plant family as rhubarb after all). Not long after that, it made its way to North America. Certainly people must have been aware of its propagative prowess as they moved the plant around. It readily roots from root and stem fragments, plus it produces extensive rhizomes, working their way as deep as 3 meters into the soil and as far as 7 meters away from the parent plant. Perhaps that should have been cause for alarm, but how could anyone have predicted just how aggressive and widespread it would soon become?

Thanks to the plant’s rhizomes, Japanese knotweed grows in thick, many-stemmed stands, pushing out, shading out, and leaving very little room for other plants. The rhizomes are also tough and can push up through gravel, cement, and asphalt. They are notorious for damaging foundations, pipes, and even pushing their way through floorboards. If that’s not enough, Japanese knotweed is pretty much impossible to kill. Herbicides may set it back, but they generally don’t take it out. Cutting it down repeatedly can slow it down, but it may also encourage it to grow more thickly and spread out more widely. Smothering it can work, but you have to be prepared to keep it smothered for quite a while. The deep rhizomes are slow to die, and they may eventually find their way outside of the smothered area, popping up to destroy your efforts to contain it. You can try to dig it out, but the amount of dirt you’d have to dig to get every last root and rhizome really isn’t feasible in most circumstances.

But hey, you can eat it, and perhaps you should. A quick internet search reveals a number of ways the plant can be consumed – purees, chutneys, compotes, sorbets. I chose to go with pickled Japanese knotweed. It seemed simple and approachable enough and a good way to determine if I was going to like it or not. Room temperature brine fermentation is pretty easy. You basically put whatever you’re wanting to pickle in a jar, add whatever spices and things you’d like, fill the jar with salty water, then seal it shut and let it sit there for a few days. Before you know it, you’ve got pickles.

There are several recipes for pickled Japanese knotweed to choose from. I went with this one. The seasonings I used were a bit different, and the stalks I had weren’t as “chubby” as recommended, but otherwise my approach was the same. After a few days, I gave them a try. I was pleasantly surprised. I thought they tasted a little like nopales. Sierra reluctantly tried them and was also surprised by how good they were. They reminded her of pickled asparagus. Other sources describe them as lemony, crunchy, tart and suggest serving them with fish, ramen, or even adding them to a cocktail made with purslane. Many of the weeds I’ve tried have been a fun experience, but not necessarily something I need to repeat. Japanese knotweed pickles, on the other hand, could become a spring tradition for me, and since we’re pretty much stuck with this plant, I’m sure to have a steady supply.

More Eating Weeds Posts on Awkward Botany:

Weeds of Boise: Ahavath Beth Israel Synagogue Garden

Anyone who has maintained a garden or small farm knows that with all the work it takes to keep up on the garden itself, outlying areas can quickly become overtaken by weeds. Low on the list of priorities, areas outside of our garden borders are ideal locations for wild urban vegetation to thrive. Pulling all the weeds within the garden is a big enough task as it is; thus, weeds out of our reach are left to their own devices, occasionally getting mown down by a string trimmer or brush mower (if time allows), but otherwise living largely unscathed. And so, places such as these are excellent for familiarizing oneself with our wild urban flora.

I found an example of this scenario at the Ahavath Beth Israel Synagogue Garden in Boise, Idaho. This community garden is a partnership between Congregation Ahavath Beth Israel (CABI) and Global Gardens, providing refugees in the area an opportunity to grow food for their families and participate in community activities.

When I visited this site, it was clear that the weeds on the edge of the garden had been mowed down at some point. New plants had popped up after the fact while others were in the process of recovering from the “haircut” and putting on new, shrubbier growth. The mowing and the fact that it was late in the summer made identifying remnants of earlier weeds too difficult to bother. Most of the weeds that I did find were either summer annuals or perennials. A visit in the spring would reveal an entirely different cast of characters.

I stayed on the border of the garden, not wanting to invade anyone’s plot or snoop around too much. The point of the visit was to highlight weeds found outside of the borders of a garden anyway. I would imagine that, since the garden is used to grow annual fruits and vegetables, most of the weeds in the beds would be annuals as well. Longer-lived weeds don’t generally tolerate regular disturbance and instead find refuge in unkept areas outside of cultivation.

Below are a few photos from the site along with a preliminary list of the weeds that I found.

salsify (Tragopogon dubius)

puncture vine (Tribulus terrestris)

field bindweed (Convolvulus arvensis)

Siberian elm (Ulmus pumila)

common mallow (Malva neglecta)

black medic (Medicago lupulina)

Weeds found at the Ahavath Beth Israel Synagogue Garden:

  • Amaranthus spp. (pigweed)
  • Bassia scoparia (kochia)
  • Chenopodium album (lamb’s quarters)
  • Chondrilla juncea (rush skeletonweed)
  • Convolvulus arvensis (field bindweed)
  • Conyza canadensis (horseweed)
  • Digitaria sanguinalis (crabgrass)
  • Epilobium brachycarpum (tall annual willowherb)
  • Euphorbia maculata (spotted spurge)
  • Hordeum jubatum (foxtail barley)
  • Lactuca serriola (prickly lettuce)
  • Malva neglecta (common mallow)
  • Medicago lupulina (black medic)
  • Oenothera biennis (common evening-primrose)
  • Plantago lanceolata (narrowleaf plantain)
  • Polygonum aviculare (prostrate knotweed)
  • Rumex crispus (curly dock)
  • Setaria sp. (foxtail)
  • Sonchus sp. (sow thistle)
  • Taraxacum officinale (dandelion)
  • Tragopogon dubius (salsify)
  • Trifolium pratense (red clover)
  • Ulmus pumila (Siberian elm)
  • Verbena bracteata (prostrate vervain)

Like all posts in the Weeds of Boise series, this will be updated as I identify and photograph more of the weeds found in this location.

Introducing Weeds of Boise

Weeds are the wild flora of our cities. Their occurrence and continued existence is not directly reliant on humans in the same way that the plants in our yards, parks, gardens, and other green spaces are. They may take advantage of the disturbance that we cause when we stir up the soil or cease maintenance in a particular spot, and they certainly appreciate the runoff from our sprinklers and the free rides their seeds get on our pets and ourselves, but they don’t need us looking after them to survive. They get by on their own whether we approve of them or not. Most may not be native to the area, but their presence is natural – undirected and involuntary – and for this reason I consider them to be a valid component of our urban flora.

If you visit a natural area outside of our cities, you are likely to find a field guide associated with that region that will help you identify many of the plants found there. However, such a field guide is not likely to exist for the plants found in a vacant lot or an urban roadside near you. Sure, there are plenty of general weed identification guides, some of which may be specific to where you live, but they are often focused on agricultural/horticultural weeds or weeds found in natural areas outside of the built environment. Few show weeds in an unmaintained urban setting the way that Peter Del Tredici’s book or Maggie Herskovits’ zine do. Clearly we need more resources that identify and document our urban floras.

Weeds of Boise is an attempt to begin that process for my corner of the world. After coming across websites like The Weedalouge (cataloging the wild plants of Philadelphia), Weeds of Melbourne (“a visual glossary of the weedy heritage of Melbourne, Australia”), and Spontaneous Urban Plants (an attempt to map weeds in urban areas around globe), I decided to start the process here in Boise, Idaho. My goal is to select locations across the city and inventory the weeds found there at different times of the year. I will keep a running list of what I find and photograph as many plants as I can. I will make a separate blog post for each location and maintain a link for each post in the Weeds of Boise page. The blog posts will be updated as I collect more data for each site. Over time I hope to have a more clear picture of what weeds are found here and how they are distributed.

Because many of these plants are cosmopolitan, the weeds found in my area are likely similar to the ones found in yours, but there may be some unique differences. If more projects like this are undertaken, we will have a better idea of the similarities and differences among our urban floras. Upon closer observation, we are likely to make some interesting discoveries. Who knows what we might find once we really start looking at these obnoxiously ubiquitous but otherwise completely ignored plants?

Weeds of Boise is also a reminder that you can botanize anytime anywhere. You don’t have to jet off to some remote location to see plants. It’s likely that there are wild plants growing right outside your front door – each one with a unique name and story and just as worth getting to know as any other.

Winter Interest in the Lower Boise Foothills

The Boise Foothills, a hilly landscape largely dominated by shrubs and grasses, are a picturesque setting any time of the year. They are particularly beautiful in the spring when a wide array of spring flowering plants are in bloom, and then again in late summer and early fall when a smaller selection of plants flower. But even when there aren’t flowers to see, plants and other features in the Foothills continue to offer interest. Their beauty may be more subtle and not as immediately striking as certain flowers can be, but they catch the eye nonetheless. Appeal can be found in things like gnarled, dead sagebrush branches, lichen covered rocks, and fading seed heads. Because the lower Boise Foothills in particular have endured a long history of plant introductions, an abundance of weeds and invasive plants residing among the natives also provide interest.

This winter has been another mild one. I was hoping for more snow, less rain, and deeper freezes. Mild, wet conditions make exploring the Foothills difficult and ill-advised. Rather than frozen and/or snow covered, the trails are thick with mud. Walking on them in this state is too destructive. Avoiding trails and walking instead on trail side vegetation is even more destructive, and so Foothills hiking is put on hold until the ground freezes or the trails dry out. This means I haven’t gotten into the Foothills as much as I would like. Still, I managed to get a few photos of some of the interesting things the lower Boise Foothills have to offer during the winter. What follows is a selection of those photos.

snow melting on the fruit of an introduced rose (Rosa sp.)

fading seed heads of hoary tansyaster (Machaeranthera canescens)

samaras of box elder (Acer negundo)

snow on seed heads of yarrow (Achillea millefolium)

gall on introduced rose (Rosa sp.)

sunflower seed heads (Helianthus annuus)

sunflower seed head in the snow (Helianthus annuus)

snow falling in the lower Boise Foothills

fading seed heads of salsify (Tragopogon dubius)

lichen on dead box elder log

seed head of curlycup gumweed (Grindelia squarrosa)

lichen and moss on rock in the snow

fruits of poison ivy (Toxicodendron radicans)

See Also: Weeds and Wildflowers of the Boise Foothills (June 2015)

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The first issue of our new zine, Dispersal Stories, is available now. It’s an ode to traveling plants. You can find it in our Etsy Shop

Zine Review: An Urban Field Guide to the Plants in Your Path

Depending on where you live in the world, it’s probably not too difficult to find a field guide to the plants native to your region. In fact, there may be several of them. They may not cover all the plants you’ll encounter in natural areas near you, but they’ll be a good starting point. Yet, considering that most of us live in cities these days, field guides to the wild plants of urban areas are sorely lacking. Perhaps that’s no surprise, as plants growing wild in urban areas are generally considered weeds and are often the same species that frustrate us in our yards and gardens. Few (if any) of these maligned plants are considered native, so that doesn’t help their case any. Why would we need to know or pay attention to these nuisance plants anyway?

I argue that we should know them, and not just so that we know our enemy. Weeds are the wild flora of our cities – they grow on their own without direct human intervention. In doing so, they green up derelict and neglected sites, creating habitat for all kinds of other organisms and providing a number of ecosystem services along the way. Regardless of how we feel about them for invading our cultivated spaces and interfering with our picture-perfect vision of how we feel our cities should look, they deserve a bit more respect for the work they do. If we’re not willing to go that far, we at least ought to hand it to them for how crafty and tenacious they can be. These plants are amazing whether we want to admit it or not.

Luckily I’m not the only who feels this way. Enter An Urban Field Guide to the Plants in Your Path, a zine written and illustrated by Maggie Herskovits and published by Microcosm Publishing. This zine is just one example of the resources we need to better familiarize ourselves with our urban floras. While there are many weed identification books out there, a field guide like this differs because it doesn’t demonize the plants or suggest ways that they can be brought under control or eliminated. Instead, it treats them more like welcome guests and celebrates some of their finer qualities. That being said, this is probably not a zine for everyone, particularly those that despise these plants, but take a look anyway. If you keep an open mind, perhaps you can be swayed.

Illustration of Pennsylvania smartweed (Polygonum pensylvanicum) from An Urban Field Guide to the Plants in Your Path

After a brief introduction, Herskovits profiles fifteen common urban weeds. Each entry includes an illustration of the plant, a short list of its “Urban Survival Techniques,” a small drawing of the plant in its urban habitat, and a few other details. The text is all handwritten, and the illustrations are simple but accurate enough to be helpful when identifying plants in the wild. The descriptions of each plant include interesting facts and background information, and even if you are already familiar with all the plants in the guide, you may learn something new. For example, I wasn’t aware that spotted spurge (Euphorbia maculata) was native to North America.

some urban survival techniques of common mullein (Verbascum thapsus)

Capsella bursa-pastoris in its urban habitat

Urban weeds often go ignored. They may not be as attractive as some of the plants found in gardens and parks around the city, and since they are often seen growing right alongside garbage, they end up getting treated that way. But if you’re convinced that they may actually have value and you want to learn a bit more about them, this guide is a great place to start. Perhaps you’ll come to feel, as Herskovits does, that “there is hope in these city plants.”

See Also: 

Eating Weeds: Chicory

Over the course of human history, plant species once esteemed or considered useful have been recategorized into something less desirable. For one reason or another, plants fall out of favor or wear out their welcome, and, in come cases, are found to be downright obnoxious, ultimately losing their place in our yards and gardens. The particularly troublesome ones are branded as weeds, and put on our “do not plant” lists. These plants are not only unfavored, they’re despised. But being distinguished as a weed doesn’t necessary negate a plant’s usefulness. It’s likely that the plant still has some redeeming characteristics. We’ve just chosen instead to pay more attention its less redeeming ones.

Chicory is a good example of a plant like this. At one point in time, Cichorium intybus had a more prominent place in our gardens, right alongside dandelions in fact. European colonizers first introduced chicory to North America in the late 1700’s. Its leaves were harvested for use as a salad green and its roots were used to make a coffee additive or substitute. Before that, cultivation of chicory for these and other purposes had been going on across Europe for thousands of years, and it still goes on today to a certain extent. Along with other chicory varieties, a red-leafed form known as radicchio and a close cousin known as endive (Chicorium endivia) are grown as specialty crops, occassionally finding their way into our fanciest of salads.

Radicchio di Chioggia (Cichorium intybus var. foliosum) is a cultivated variety of chicory. (via wikimedia commons)

Chicory’s tough, adaptable nature and proclivity to escape cultivation have helped it become widespread, making itself at home in natural areas as well as urban and rural settings. Its perennial life history helps make it a fixture in the landscape. It sends down a long, sturdy taproot and settles in for the long haul. It tolerates dry, compacted soils with poor fertility and doesn’t shy away from roadside soils frequently scoured with salts. It’s as though it was designed to be a city weed.

Unlike many other perennial weeds, chicory doesn’t spread vegetatively. It starts its life as a seed, blown in from a nearby plant. After sprouting, it forms a dandelion-esque rosette of leaves during its first year. Wiry, branched stems rise up from the rosette in following years, reaching heights of anywhere from about a foot to 5 or 6 feet. When broken, leaves, stems, and roots ooze a milky sap. Abundant flowers form along the gangly stems. Like other plants in the aster family, each flower head is composed of multiple flowers. Chicory flower heads are all ray flowers, lacking the disc flowers found in the center of other plants in this family. The petals are a brilliant blue – sometimes pink or white. Individual flowers last less than a day and are largely pollinated by bees. The fruits lack the large pappus found on dandelions and other close relatives, but the seeds are still dispersed readily with the help of wind, animals, and human activity.

chicory (Cichorium intybus) via wikimedia commons

The most commonly consumed portions of chicory are its leaves and roots. Its flowers and flower buds are also edible. Young leaves and blanched leaves are favored because they are the least bitter. Excluding the leaves from light by burying or covering them up keeps them pale and reduces their bitter flavor. This is standard practice in the commercial production of certain chicory varieties. The taproots of chicory are dried, roasted, and ground for use as a coffee substitute. They are also harvested commercially for use as a natural sweetener due to their high concentration of inulin.

my puny chicory root

I harvested a single puny chicory root in order to make tea. On my bike ride to work there is a small, sad patch of chicory growing in the shade of large trees along the bike path. I was only able to pull one plant up by the roots. The others snapped off at the base. So, I took my tiny root, dried and roasted it in the oven, and ground it up in a coffee grinder. I followed instructions for roasting found on this website, but there are many other sources out there. I had just enough to make one small cup of tea, which reminded me of dandelion root teas I have had. Sierra found it to be very bitter, and I agreed but still enjoyed it. I figure that wild plants, especially those growing in stressful conditions like mine was, are likely to be more bitter and strong tasting compared to coddled, cultivated ones found in a garden.

roasted chicory root

roasted and ground chicory root

When I find a larger patch of feral chicory, I hope to try one of several recipes included in Luigi Ballerini’s book, A Feast of Weeds, as well as other recipes out there. I’ll be sure to let you know how it goes.

Are you curious to know how chicory became such a successful weed in North America? Check out this report in Ecology and Evolution to learn about the genetic explanation behind chicory’s success.

Investigating the Soil Seed Bank

Near the top of the world, deep inside a snow-covered mountain located on a Norwegian island, a vault houses nearly a million packets of seeds sent in from around the world. The purpose of the Svalbard Global Seed Vault is to maintain collections of crop seeds to ensure that these important species and varieties are not lost to neglect or catastrophe. In this way, our food supply is made more secure, buffered against the unpredictability of the future. Seed banks like this can be found around the world and are essential resources for plant conservation. While some, like Svalbard, are in the business of preserving crop species, others, like the Millennium Seed Bank, are focused on preserving seeds of plants found in the wild.

Svalbard Global Seed Vault via wikimedida commons

Outside of human-built seed banks, many plants maintain their own seed banks in the soil where they grow. This is the soil seed bank, a term that refers to either a collection of seeds from numerous plant species or, simply, the seeds of a single species. All seed bearing plants pass through a period as a seed waiting for the chance to germinate. Some do this quickly, as soon as the opportunity arises, while others wait, sometimes for many years, before germinating. Plants whose seeds germinate quickly, generally do not maintain a seed bank. However, seeds that don’t germinate right away and become incorporated in the soil make up what is known as a persistent soil seed bank.

A seed is a tiny plant encased in a protective layer. Germination is not the birth of a plant; rather, the plant was born when the seed was formed. The dispersal of seeds is both a spatial and temporal phenomenon. First the seed gets to where it’s going via wind, water, gravity, animal assistance, or some other means. Then it waits for a good opportunity to sprout. A seed lying in wait in the soil seed bank is an example of dispersal through time. Years can pass before the seed germinates, and when it does, the plant joins the above ground plant community.

Because seeds are living plants, seeds found in the soil seed bank are members of a plant community, even though they are virtually invisible and hard to account for. Often, the above ground plant community does not represent the population of seeds found in the soil below. Conversely, seeds in a seed bank may not be representative of the plants growing above them. This is because, as mentioned earlier, not all plant species maintain soil seed banks, and those that do have differences in how long their seeds remain viable. Depending on which stage of ecological succession the plant community is in, the collection of seeds below and the plants growing above can look quite different.

Soil seed banks are difficult to study. The only way to know what is truly there is to dig up the soil and either extract all the seeds or encourage them to germinate. Thanks to ecologists like Ken Thompson, who have studied seed banks extensively for many years, there is still a lot we can say about them. First, for the seeds of a plant to persist in the soil, they must become incorporated. Few seeds can bury themselves, so those with traits that make it easy for them to slip down through the soil will have a greater chance of being buried. Thompson’s studies have shown that “persistent seeds tend to be small and compact, while short-lived seeds are normally larger and either flattened or elongate.” Persistent seeds generally weigh less than 3 milligrams and tend to lack appendages like awns that can prevent them from working their way into the soil.

The seeds of moth mullein (Verbascum blattaria) are tiny and compact and known to persist in the soil for decades as revealed in Dr. Beal’s seed viability experiment. (photo credit: wikimedia commons)

Slipping into cracks in the soil is a major way seeds move through the soil profile, but it isn’t the only way. In a study published in New Phytologist, Thompson suggests that “the association between small seeds and possession of a seed bank owes much to the activities of earthworms,” who ingest seeds at the surface and deposit them underground. Later, they may even bring them back up the same way. Ants also play a role in seed burial, as well as humans and their various activities. Some seeds, like those of Avena fatua and Erodium spp., have specialized appendages that actually help work the seeds into the soil.

Not remaining on the soil surface keeps seeds from either germinating, being eaten, or being transported away to another site. Avoiding these things, they become part of the soil seed bank. But burial is only part of the story. In an article published in Functional Ecology, Thompson et al. state that burial is “an essential prelude to persistence,” but other factors like “germination requirements, dormancy mechanisms, and resistance to pathogens also contribute to persistence.” If a buried seed rots away or germinates too early, its days as a member of the soil seed bank are cut short.

The seeds of redstem filare (Erodium circutarium) have long awns that start out straight, then coil up, straighten out, and coil up again with changes in humidity. This action helps drill the seeds into the soil. (photo credit: wikimedia commons)

Soil seed banks can be found wherever plants are found – from natural areas to agricultural fields, and even in our own backyards. Thompson and others carried out a study of the soil seed banks of backyard gardens in Sheffield, UK. They collected 6 soil cores each (down to 10 centimeters deep) from 56 different gardens, and grew out the seeds found in each core to identify them. Most of the seeds recovered were from species known to have persistent seed banks, and to no surprise, the seed banks were dominated by short-lived, weedy species. The seeds were also found to be fairly evenly distributed throughout the soil cores. On this note, Thompson et al. remarked that due to “the highly disturbed nature of most gardens, regular cultivation probably ensures that seeds rapidly become distributed throughout the top 10 centimeters of soil.”

Like the seed banks we build to preserve plant species for the future, soil seed banks are an essential long-term survival strategy for many plant species. They are also an important consideration when it comes to managing weeds, which is something we will get into in a future post.

Introducing Herbology Hunt

This is a guest post by Jane Wilson.

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Many people are “plant blind”. They walk through areas of fantastic wildlife or just down their street without noticing what grows there. Even plants growing in the gutter have an interesting backstory.

The term “Plant Blindness” was first put forth by Wandersee and Schlusser in 1998. Without an appreciation of plants in the ecosystem, people will be less likely to support plant research and conservation.

Herbology Hunt was born out of a love of plants and wild places and a determination to get kids outdoors and really looking at their environment. One of the founders started Wildflower Hour on Twitter – a place for people to share photos of wildflowers found in Britain and Ireland – and from this was stemmed a children’s version, which became Herbology Hunt. The Herbology Hunt team put together spotter sheets for each month of the year. Each sheet includes five plants that can be found throughout the month. They were made available as a free download, so schools and individuals can print them for use on a plant hunt.

By the end of 2018, we had created a year’s worth of spotter sheets. We are now looking to promote their use throughout Great Britain. Eventually we want to reward children who find 50 of the plants with a free T-shirt, and we will be looking for sponsors to support this. We have been supported by the Botanical Society of Britain and Ireland and the Wild Flower Society who have made the monthly spotter sheets available. They can be downloaded here or here.

Herbology Hunt Spotter Sheet for January

The Wild Flower Society has a great offer for Juniors interested in plants – it costs £3 to join and you get a diary to record your finds.

Going outdoors and noticing wildlife has been shown in some scientific studies to improve cardio-vascular health and mental health. A herbology hunt must surely be a good thing to do with children to help them get into a better lifestyle that will benefit their future health. We hope that many families and schools will use our spotter sheets as a way to help children become more passionate about the environment and enjoy the benefits of being outdoors.

Check out the Wildflower Hour website for more information about Herbology Hunt, along with instructions on how to get involved in #wildflowerhour, plus links to social media accounts and the Wild Flower (Half) Hour podcast.

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Also: Check out Jane Wilson’s website – Practical Science Teaching – for more botany-themed educational activities.

Moving Your Ecosystem Forward – An Arborist’s Application of Ecological Principles in the Urban Landscape

This is a guest post by Jeremiah Sandler.

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Ecosystems are everywhere – interconnected and interdependent systems of biology, climate, ecology, and geography. The inside of your house is an ecosystem with its own micro-climate, life (including but not limited to you), and topography. Everywhere you go, you’re in some kind of ecosystem.

The same is more obviously true about your landscape. In my area of the U.S. (southeast Michigan), forests and wetlands are often removed to build suburbs. Both the appropriate soil and ecologically relevant plants are removed from the site. After construction, these areas are re-planted with genetically inadequate plants in poor soil. The ecosystem is modified at a rate faster than most organisms can adapt. Landscape designs common in the suburbs are inadequate in maintaining biodiversity and healthy, natural ecosystems.

In some lucky areas, there are communities doing their best to maintain a strong and natural forest canopy. Leaving secondary forests relatively untouched during construction should be the standard when developing areas for humans.

Ecosystems evolve and change, and one can argue that human-caused mass deforestation is simply another driver of ecosystem evolution. While this may be true, it is a driver that influences the ecosystem at a much greater magnitude than other factors. It just so happens to be mitigable or avoidable altogether.

What can cause an ecosystem to change?

Let’s use the trees in a natural forest ecosystem as an example. Disturbances in any ecosystem drive biological adaptation and behavioral changes in the organisms within it. Disturbances such as fire, wind events, floods, drought, and pathogens alter the forest canopy. Fire may kill smaller trees and wind events can blow trees over. Such disturbances open the canopy and allow dormant seeds to germinate in the new sunlight, which gives additional genetic material a shot in the world.

Ecological disturbance is vital to plants, animals, and microbes because it keeps their genetic material up-to-date with evolving pathogens and changing environments. Up-to-date trees need less work. They are more prepared for their environment and its diseases, as evidenced by their parents successfully reproducing.

We can’t control all ecological disturbances, but in the urban environment we do our best to avoid major ones. Understandably, right? We aren’t fond of wildfire, nor do we want flooding anywhere near our homes.

Applied ecosystem principles on the job

Oftentimes in large, human constructed landscapes, only upper and middle canopies exist; sub-canopy layers are missing. This is surprisingly common in forest ecosystems, especially in suburban areas. Forests like this are considered to have a closed canopy.

Closed-canopy forests are naturally occurring and are not necessarily bad. The thick shade cast by the upper canopy is very dense and prevents most understory growth. Over time closed-canopy forests will evolve and change – large trees or limbs come down in the wind, flooding occurs, lightning strikes, or diseases are introduced. Whatever the disturbance, the newly opened canopy once again helps move the ecosystem forward.

Disturbance by pruning

A client of ours lives on a beautiful property in a dry-mesic southern forest (a closed-canopy forest). Due to all the trees on the property, this client sought advice from arborists. The client’s smart choice lead us to an important solution.

Various large species of both white and red oaks dominate the overstory and upper emergent layers of the canopy. The trunks of these towering trees are far apart. Below these titan trees are some slightly shorter oaks, an american beech, and a few hickory species residing in the midstory. About 40 feet below are various types of moss, some stunted sedges, violets, forest grasses – a sparse herbaceous understory. Beyond that there were several patient serviceberries here and there, and a single red maple, about 1.5 inches in diameter and 15 feet tall at most.

Allegheny serviceberry (Amelanchier laevis) – via wikimedia commons

The area has been undisturbed for a long time (it doesn’t even get mowed), and with the presence of oak wilt in southeast Michigan, we steered away from planting anywhere in the root zone, as it poses a risk for oak wilt infection. Sure, we could plant an over-designed landscape to be manicured, but we had other ideas in mind.

Direct application with two solutions

We asked the client how long ago the red maple and serviceberries volunteered themselves into their landscape. Together we traced the germination back to a wind event that knocked a large limb down years ago. The red maple and serviceberries popped up as a result of new sunlight, yet according to the client, these plants hadn’t grown much in height during the last decade or so. Why might this be? A mature plant can close holes in the canopy faster than lower story plants can, so they no longer receive as much light as they once had.

The next time a limb falls, the maple and serviceberries will have another explosive growth spurt. There are also other dormant seeds to germinate every time a disturbance like that occurs. This is an example of another natural phenomenon called forest succession. It is another way forest ecosystems change.

Planting foreign species in place of the native ones takes away important food sources and habitat for surrounding wildlife. So rather than planting cultivar clones and ecologically useless plants – plants that don’t support other lifeforms – into the existing ecosystem, we proposed we could either do strategic crown thinning or just wait for mother nature to do it for them.

Course of action

My associates and I operate on a “less is more” approach. Not touching this ecosystem is our alternative to modifying the canopy. Like a human patient undergoing surgery, cutting open any organism exposes it to infection. In time, either a natural disturbance will come through to modify the canopy, or the trees will naturally shed lower limbs on their own – a process called cladoptosis.

Strategic branch removal will open up the canopy, allowing more sunlight to the ground below, while keeping the trees looking true to their natural form. The climbing team would be using a type of pruning called refracturing. The openings will simulate a wind event disturbance. As a result, the plants that germinate will be the most competitive, hardy, resistant, and genetically up-to-date plants. This truly is “right plant, right place,” provided no invasive buckthorns pop up.

If the customer does want to go forward with disturbance-by-pruning, the proposal is to open the canopy during winter, as most of the canopy are oak trees. The risk of infecting these trees is reduced significantly by pruning in the winter when the vectors for oak wilt are dormant.

The canopy holes would be placed where the homeowner wants more trees. One benefit of pruning the trees is that disturbance is controlled, rather than a wind disturbance causing a chaotic breakage into the house, for example.

Observation would begin early the following spring. We will watch for germination; it’s expected that the plants that do germinate won’t survive the competition.

What’s important about any of this?

The arborist-homeowner relationship highlighted above is an exemplar of proper arboriculture. We offered expertise along with our services. The exchange saved the homeowner hundreds of upfront costs from the installation of a landscape, as well as future maintenance costs.

Assuming it isn’t under human-induced stress, no forest needs human intervention. In this project, we would want to see natural phenomena form the landscape in this client’s yard. It is our preference to leave the current closed-canopy forest alone.

The benefits of using naturally occurring trees are plentiful. In general, up-to-date trees are more prepared for your ecosystem and support the wildlife that co-evolved with them. An ever-increasingly displaced wildlife population will happily occupy new habitat; they’re here too, after all.

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Jeremiah Sandler lives in southeast Michigan, has a degree in horticultural sciences, and is an ISA certified arborist. Follow him on Instagram: @jeremiahsandler