Final report for FS22-343
Project Information
This project explored the viability of cultivating mushrooms on Albizia julibrissin (Mimosa), an invasive tree species prevalent in urban Birmingham, Alabama. The hypothesis was that mimosa, which grows abundantly on blighted lots, could serve as a low-cost substrate for growing gourmet mushrooms, potentially turning waste into wealth for small-scale urban farmers.
Logs of mimosa and paper mulberry (a control substrate previously rated as "suitable" by mushroom suppliers) were inoculated with four species: Golden Oyster, Blue Oyster, Chestnut, and Nameko. The project tracked yields over two years.
Our project will clear and clean up one of the overgrown lots in Fountain Heights (located at 1707 14th Ave N, Birmingham, AL 35204) currently owned by Fountain Heights Farms to complete our project testing. On the lot are Mimosa and paper Mulberry, both of which will be used to complete the 2-year trial.
We will be using the Birmingham GIS mapping system to calculate the number of empty lots in the Fountain Heights neighborhood and using the data gathered by Cawaco and the Birmingham Urban Forestry group to calculate the number of existing Mimosa trees in the area. Both data sources will help estimate the potential for other area urban farmers.
During the two year trial we will be answering the following questions:
- Given the abundance of the fast-growing, invasive tree species Mimosa (Albizia julibrissin) found on urban lots in Birmingham, AL, are Mimosa tree logs suitable for growing Chestnut, Nameko, Golden Oyster, and Blue Oyster varieties of mushrooms?
- What kinds of yields will they return during harvest compared to the tested and rated “suitable” Paper Mulberry (Broussonetia papyrifera)
- For how long will the logs continue to produce after the first flush on Mimosa wood?
- Is there a quality of life improvement to the surrounding neighbors as a result of clearing and cleaning the overgrown lot?
We plan on using Paper Mulberry (Broussonetia papyrifera) as the control since Mulberry has already been rated by North Spore, our nationally-recognized mushroom spore supplier, as "Suitable" for growing all of these varieties. We will be inoculating 25 of each type of tree, both being harvested from the farm lot and the surrounding areas. We will measure mushroom results via observation and physical measurements and record the data daily in a spreadsheet. We will measure community quality of life improvements by using four self-reported surveys.
With the help of the Fountain Heights Neighborhood Association, we have already acquired an overgrown lot requiring clean-up. We plan to clean up the lot with the help of community volunteers. We will then identify and harvest forty (40) Mimosa logs and forty (40) Paper Mulberry logs on which to grow each of the four varieties as listed in the table below.
|
Mushroom Variety |
Number of Mimosa wood logs |
Number of P. Mulberry logs |
|
Golden Oyster ('Saffron' Pleurotus citrinopileatus NSPC1) |
10 |
10 |
|
Chestnut (Speckled Chestnut' Pholiota adiposa NSPA1) |
10 |
10 |
|
Nameko ('Jelly Roll' Pholiota nameko NSPN1) |
10 |
10 |
|
Blue Oyster (Pleurotus ostreatus NSPO9) |
10 |
10 |
We will then identify mushroom log growing areas within the lot, host four mushroom inoculation workshops (two in spring and two in fall) for other urban farmers and interested community members to innoculate the mushroom logs and place the logs, and then consistently measure the actual yield of each mushroom variety on Mimosa wood logs versus the Paper Mulberry “control” logs. We will also be working closely with the Fountain Heights Neighborhood Association to survey neighbors in years one and two to help measure the quality of life changes related to the mushroom farm space.
Key Research Questions:
1. Can mimosa logs support mushroom cultivation?
2. How does yield compare to a known suitable substrate (Paper Mulberry)?
3. What is the duration and productivity of each log type?
4. Can the reclamation of blighted lots for mushroom cultivation benefit the surrounding community?
Cooperators
- (Educator)
Research
Materials and methods:
The project team sourced Mimosa logs from overgrown urban lots and inoculated them with mushroom spores. The logs were then stacked in a shaded area and monitored for moisture and temperature levels. The team harvested mushrooms as they grew, weighing and recording the yield of each variety.
In the first year, the project inoculated 40 logs Paper Mulberry (control logs) and 40 Mimosa logs (test logs) and grew a total of 31.2 lbs of mushrooms on the Paper Mulberry control logs and 0 pounds of mushrooms on the Mimosa wood logs, with the most successful variety being the Blue Oyster mushroom on the Paper Mulberry logs. We are concerned that there may have been some other factors in the lack of growth from the Mimosa logs so we will be inoculating a second set of 40 logs while continuing to monitor the progress of the existing logs.
The project successfully engaged with 24 neighbors and 19 farmers, and 2 agricultural professionals through educational and outreach activities, raising awareness about the use of invasive species for productive use while responsibly managing their growth.
Findings:
Year 1:
Paper Mulberry - Median Yield: 6.5 lbs/log; Total: 78 lbs ($936.00)
Mimosa - Median Yield: 0 lbs/log; Total: 0 lbs ($0.00)
Year 2:
Paper Mulberry - Median Yield: 7.25 lbs/log; Total: 87 lbs ($1,044.00)
Mimosa - Median Yield: 0 lbs/log; Total: 0 lbs ($0.00)
The data confirms that mimosa wood is not a viable substrate for these types of mushroom cultivation using the log inoculation method - inoculated peg method. Paper mulberry logs performed consistently and demonstrated suitability.
Lessons Learned
Mimosa logs yielded no mushrooms across two full growing seasons, indicating unsuitability for cultivation.
In contrast, paper mulberry logs showed strong performance, validating the inoculation methods used.
Possible reasons for mimosa’s failure include anti-fungal compounds or structural qualities inhibiting fungal colonization.
The results saved other farmers from investing labor and resources into mimosa logs and provided valuable data for urban agriculture systems.
Outreach Objectives & Achievements
- On-Farm Workshops - Completed: Trained 120+ participants.
2. National Presentation - Completed.
3. Conference Presentations - Completed: 2024 BUGS Conference & 2025 SOWTH Conference.
4. Educational Report - Completed: Bilingual report (English/Spanish).
5. Social Media Campaign - Completed: 52 posts shared educational content.
Community & Equity Impact
Though mimosa logs didn’t produce mushrooms, the project led to meaningful community gains:
- Cleared blight and improved safety and aesthetics of urban lots.
- Provided hands-on mushroom training to Black and BIPOC urban farmers.
- Created transparent, replicable research shared through accessible platforms.
- Reinforced trust and knowledge-sharing within Fountain Heights and beyond.
Educational & Outreach Activities
Participation Summary:
The project team conducted several educational and outreach activities, including on-farm demonstrations, tours, and workshops. The team engaged with 24 neighbors, 19 farmers and 2 agricultural professionals, raising awareness about the use of invasive species for productive use while responsibly managing their growth.
Learning Outcomes
Farmers who participated in the project gained knowledge about the use of invasive species for productive use, including the potential viability of growing mushrooms on Mimosa logs. Participants also gained awareness about responsible management practices for invasive species and some farmers shared indigenous knowledge of traditional medicinal uses for mimosa flowers.
Project Outcomes
Economic Impact:
While the project disproved the viability of Albizia julibrissin (mimosa) logs for these varieties of mushroom cultivation, it confirmed that Paper Mulberry is a productive, low-cost substrate. Over two years, Paper Mulberry yielded a total of 165 lbs of mushrooms, valued at approximately $1,980, with consistent production across both years. This yield, achieved using freely sourced urban wood, demonstrates a replicable, scalable income stream for small urban farmers, especially in densely populated areas with limited arable land. The low space requirements of log inoculation allow for successive batches, making this technique ideal for micro-enterprises and side-income generation in BIPOC neighborhoods.
Environmental Impact:
The project supported urban land reclamation by transforming blighted lots in Birmingham into active mushroom-growing spaces. Although mimosa was found unsuitable, the study tested the hypothesis of using invasive tree species as productive substrates. The logs were harvested from overgrown areas, directly contributing to lot cleanup and invasive species management. Through this, the project advanced the concept of “productive conservation” — using invasive or underutilized resources for regenerative food systems.
Social Impact:
The project directly engaged over 120 community members through on-farm mushroom inoculation workshops and presented findings at national and regional conferences (BUGS 2024, SOWTH 2025). Social media campaigns and bilingual educational materials increased public accessibility. According to community surveys, participants reported improved perceptions of safety, pride, and increased interest in mushroom cultivation. The presence of the urban mushroom farm boosted community well-being, strengthened intergenerational connections, and empowered urban growers with practical agroecological knowledge. As noted in the SOWTH presentation, elders reported feeling more connected and purposeful, and neighbors collaborated to clear lots and maintain growing spaces.
In short, the project advanced agricultural sustainability by:
-
Identifying scalable, low-cost substrates for mushroom cultivation,
-
Demonstrating regenerative uses for urban tree species,
-
Enhancing food access and agro-literacy in urban communities,
-
Contributing replicable models for small-farm diversification.
Recommendations for Future Study:
-
Expand Substrate Trials:
Since mimosa logs proved unsuitable, future studies should test other fast-growing urban trees like Tree of Heaven (Ailanthus altissima), Bradford Pear, and Japanese Zelkova. These species also proliferate on urban lots and may offer similar environmental benefits with better fungal compatibility. -
Investigate Mimosa’s Anti-Fungal Properties:
The complete absence of fruiting suggests mimosa may contain compounds that actively inhibit fungal colonization. Chemical analysis or controlled laboratory trials could validate this hypothesis and inform substrate use in mushroom agriculture. -
Model Micro-Enterprise Structures:
The project demonstrated community interest in mushroom farming. Future projects could pilot cooperative mushroom micro-enterprises, including collective inoculation, harvest, marketing, and profit-sharing, especially among seniors and youth. -
Urban Lot Transformation Metrics:
While community response was positive, systematic tracking of metrics like air quality, heat island reduction, or neighborhood walkability after lot reclamation would strengthen the case for urban ag as a climate resilience tool.
Final Comments:
This project would not have been possible without SARE’s support and belief in farmer-led inquiry. The flexibility and encouragement to pursue community-based participatory research allowed Fountain Heights Farms to blend scientific rigor with cultural relevance. We believe this model — led by small urban farmers, grounded in justice, and centered in community — is not only effective, but essential to achieving truly sustainable agriculture in the South.