Weeds of Boise: Ridenbaugh Canal between Vista Avenue and Federal Way

Like so many urban areas that had their start as agricultural communities, Boise is home to a vast network of canals. Major canals, such as the New York Canal, stretch across the valley and divert water through an extensive series of laterals. This water once irrigated numerous farms and orchards found within Boise and beyond. While large farms still exist outside of Boise – as well as a few small farms within city limits – much of this water now goes to irrigating lawns and gardens of city residents who are lucky enough to have access to it.

Because of the way these canals weave their way throughout Boise and into the surrounding area, there is interest in transforming them into transportation corridors for bicyclists and pedestrians. This would be in addition to the Boise River Greenbelt, a 30 mile trail system that already exists along the Boise River, and would vastly increase access to alternative and sustainable transportation for people living in the area.

Accessibility to these canals is limited, but where trails are available, they are a great place to observe wild urban flora and urban wildlife. This month, I explored a section of the Ridenbaugh Canal that extends about a thousand feet between Vista Avenue and Federal Way. There is a wide, dirt trail on the north side of the canal, easily accessible from Vista Avenue, that ends at the railroad tracks which run alongside Federal Way. The bank of the canal is steep, but there is one spot at the end of the trail that leads down to the water’s edge. Weeds are abundant along both sides of the trail, so it’s a great place to become familiar with common members of our wild urban flora.

blue mustard (Chorispora tenella)

henbit (Lamium amplexicaule)

flixweed (Descurainia sophia)

A long strip of white top (Lepidium sp.) flanks a fence alongside the trail.

A pair of Canada geese and four goslings have made this stretch of the canal their home.

redstem filaree (Erodium cicutarium)

bulbous bluegrass (Poa bulbosa)

Japanese knotweed (Reynoutria japonica)

Weeds found at Ridenbaugh Canal between Vista Avenue and Federal Way:

  • Bromus tectorum (cheatgrass)
  • Ceratocephala testiculata (bur buttercup)
  • Chondrilla juncea (rush skeletonweed)
  • Chorispora tenella (blue mustard)
  • Descurainia sophia (flixweed)
  • Draba verna (spring draba)
  • Epilobium sp. (willowherb)
  • Erodium cicutarium (redstem filaree)
  • Gallium aparineĀ (cleavers)
  • Hordeum murinum ssp. glaucum (smooth barley)
  • Lactuca serriola (prickly lettuce)
  • Lamium amplexicaule (henbit)
  • Lepidium sp. (white top)
  • Malva neglecta (common mallow)
  • Medicago lupulina (black medic)
  • Medicago sativa (alfalfa)
  • Poa bulbosa (bulbous bluegrass)
  • Reynoutria japonica (Japanese knowtweed)
  • Rumex crispus (curly dock)
  • Secale cereale (cereal rye)
  • Taeniatherum caput-medusae (medusahead)
  • Taraxacum officinale (dandelion)
  • Tragopogon dubius (salsify)

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. If there is a canal near you, get outside and take a look at what’s growing along the banks. Let me know what you find in the comment section below.

Weeds of Boise: Abandoned Pizza Hut on Ann Morrison Park Drive

There is an old Pizza Hut on the corner of Ann Morrison Park Drive and Lusk Street. I’m not sure how long it’s been closed (if someone knows for sure, please let me know), but it has to be well over a year – probably several years. It’s clear that the landscaping has not been maintained for a while. The turf grass in the hellstrips is now mostly weeds, the Callery pears and crabapples are in need of some serious pruning, and the mugo pines and horizontal junipers are slowly dying off. On the other hand, the Oregon grapes and barberries look just fine. They never really needed our help anyway.

I like checking out lots with recently abandoned buildings because you can see in real time just how quickly weeds take over once humans stop their meddling. As the months and years pass, and as the plants that humans intentionally placed there decline, it becomes increasingly obvious that weeds truly are the wild flora of our cities.

My first few visits to this site were on March 21st, 25th and 28th of 2020. During those visits, I made a list of all the weeds that I could easily identify and noted a few individuals that I will need to come back to. What follows are photos of a few of the weeds I came across, along with a list of the weeds I was able to identify.

Every lot needs a dandelion (Taraxacum officinale).

Common mallow (Malva neglecta) in mulch.

The turf grass in the hellstrips has been replaced by several different weeds including tiny, early spring favorites like bur buttercup (Ceratocephala testiculata) pictured here and spring draba (Draba verna).

Common groundsel (Senecio vulgaris) is prolific in a bed on the north side of the building. On the east side, this plant had already flowered and gone to seed by mid-March.

The tough taproot of alfalfa (Medicago sativa) easily works its way into cracks in pavement and concrete.

A bull thistle rosette (Cirsium vulgaris) perhaps?

Cheatgrass (Bromus tectorum) was common on the site, including (perhaps not surprisingly) in this parking block.

horseweed seedling (Conyza canadensis)

Weeds found at the abandoned Pizza Hut on Ann Morrison Park Drive:

  • Bromus tectorum (cheatgrass)
  • Ceratocephala testiculata (bur buttercup)
  • Cirsium vulgare (bull thistle)
  • Conyza canadensis (horseweed)
  • Draba verna (spring draba)
  • Hordeum murinum ssp. glaucum (smooth barley)
  • Lactuca serriola (prickly lettuce)
  • Malva neglecta (common mallow)
  • Medicago sativa (alfalfa)
  • Poa bulbosa (bulbous bluegrass)
  • Rumex crispus (curly dock)
  • Senecio vulgaris (common groundsel)
  • Taraxacum officinale (dandelion)
  • Ulmus pumila (Siberian elm)

This post will be updated as I identify more of the weeds and capture more photos. I also anticipate that this lot will not be abandoned for that much longer. It’s located near Boise State University in an area that has seen a lot of development in the past few years. I can’t imagine prime real estate like this will stay feral indefinitely. Until something is done with it, I’ll keep checking in.

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.