How Hydroponics is Revitalizing Rosewood's Wetlands
Hydroponics - from the Greek roots hydro (water) and ponos (work)₁ - is a method of growing plants without any soil. In other words, when water is doing all of the work. While it might sound futuristic or complicated, hydroponics has actually been used by people to grow plants for thousands of years₁. It can be a great way of growing many plants quickly with limited space and resources. The Truckee Meadows Parks Foundation has started its own hydroponics project in order to grow native plants to plant at the Rosewood Nature Study Area.
The wetland restoration team that works at Rosewood is dedicated to restoring the nature study area to a healthy wetland ecosystem (see the Project Overview for more information about the Rosewood project). Planting native vegetation is one of the major conservation actions the restoration technicians undertake to restore Rosewood’s wetlands. Native vegetation is important because it provides habitat and food for local wildlife, stabilizes streambanks, helps maintain healthy soils, provides shade, and helps fight against the encroachment of weeds and invasive species.
Truckee Meadows Parks Foundation hosts two planting events a year at Rosewood, where community volunteers come to plant hundreds of plants on the wetland (our spring event, Plantapalooza, happened in May - you can read Jenny's blog to learn more about it). A majority of the plants that are planted at these events are sourced from the Washoe State Tree Nursery.
The Washoe State Tree Nursery provides an amazing resource for Rosewood’s restoration, but relying entirely on a third party for sourcing plants puts restrictions on our restoration efforts. The wetland restoration team is trying to become less reliant on purchasing plants by growing our own. Our hydroponics project is a major step towards this goal. Our hydroponics system allows us to grow our own plants from cuttings taken from already growing plants.
As stated above, hydroponics is a method of growing plants without any soil, using only water and nutrients. While it sounds like it might be a complicated process, our setup is actually very simple. We have a tote bin that is filled with water (which has nutrients dissolved in it). Inside the bin, we have a small pump connected to a sprinkler system, made of PVC piping with spray nozzles attached.
The lid of the tote bin has holes cut out, where we place all of the plants. The plant is placed so the stems and leaves are above the lid, and the roots are below it inside the bin. The water level is low enough that the roots are entirely suspended in the air. The pump then takes water from the bin, and continuously sprays it up and onto the plant roots, providing them with a constant supply of moisture and nutrients. Finally, we have grow lights set to mimic sunlight, so the plants can grow while indoors.
We grow a few different species of plants in the hydroponics system, but the main species at this point has been Fremont Cottonwood (Populus fremontii). We chose Fremont Cottonwoods because they are a native riparian tree species, they grow quickly, they help with streambank stabilization, and they provide shade for both wildlife and guests on the trail.
To grow them, we take cuttings from local, living trees. We find trees that are well established and healthy, and that have newly grown branches. New stem growth is flexible, it has not turned woody yet. It is ideal for propagation because the tissues in that branch are still growing.
We cut a few of these young branches that still have growing tissue and bring them back to Rosewood. We then place these cuttings in the hydroponics system, with the buds facing the lights and the cut edge on the bottom, exposed to the spraying water.
In as little as one to two weeks, leaves begin growing from the buds, and new roots start growing from the cut edge! These roots are called adventitious roots, which means that they have grown from a part of the plant that was not originally root tissue₂. In the case of cuttings, they are caused by wounding on the stem where we cut it off of the tree. The plant responds to the wound by sending hormones and acids to the wound site that promote root tissue growth₂.
While the cuttings are growing, we monitor them twice a week to track their growth and any diseases they might have. We take pictures each time we monitor them, to have a record of how they grew.
After a few weeks, when the roots are big enough, we transfer them to pots with soil. The cutting in Figures 4 and 5 was ready to be transferred to soil after only two weeks! We move them to pots first, rather than directly planting them in the ground, because these new roots have never experienced soil and are used to very high levels of moisture. By planting them in pots, we can add fertilizers to the soil and water them regularly to support them. Giving them time to grow more roots in the soil prepares them to be able to survive being planted outdoors, where they will be watered less and have less nutrient-rich soil.
With the help of many volunteers, we planted almost 50 of these potted trees at Rosewood during the Plantapalooza! Since this is the first year of planting our own cuttings, we will continue to monitor their survival to see how well they handle the transition. To support them, we are watering them regularly. However, hopefully once they’ve grown more and become more established, we will wean them off of water until they are entirely self sufficient.
The restoration team is hard at work finding innovative ways to improve our restoration efforts. I am excited about the prospects of our hydroponics system, and I hope it allows for an easy and sustainable source of new plants for Rosewood. Hopefully in the coming years, there will be plenty of established, native trees growing at the Rosewood Nature Study Area! If you’re interested in becoming involved, keep an eye out for future TMPF planting events.
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About the Author
Originally from Reno, Chloe grew up camping and hiking in the area. This fostered a desire to protect the environment, leading her to receive her Bachelor’s degree in Natural Resources Conservation from the University of British Columbia. However, her love for the Great Basin desert brought her back to Reno where she is now excited to be working as a Wetland Restoration Technician. When not at work, you can find Chloe playing board games, roller skating, or reading.
Interesting and well presented article. Looking forward to seeing the trees. Thank you
Super interesting and informative, thanks Chloe!
What a great project! Growing your own plants will be a huge help in revitalizing the wetland!