Support the Future of St. Louis Community Gardens on St. Louis Gives Day 2018
The Power of Growing Food
About Give STL Day
Give STL Day is a 24-hour day of online giving happening this year on May 2. It is an opportunity for Gateway Greening to invite the community of St. Louis to help us further the work that we do.
Gateway Greening supports more than 200 community and school gardens in the St. Louis area, that do more than provide a beautifying space in communities. They connect residents of all ages and backgrounds to their food and to each other. Gardens provide joyful spaces where people can interact and share their lives and the fresh food that they grow.
Written by Mary Anne Pikrone, Tower Grove East Community Garden Leader.
Three and a half years ago, as my husband and I were taking a get-acquainted drive through the neighborhood we chose to live in, we came upon folks working in the Tower Grove East Community Garden. I’d given up backyard gardens in Richmond, VA., and Toledo, Ohio, and was prepared to do with just a postage stamp yard behind our new location on Louisiana Ave. So I walked into the garden, asked about available beds, and within a couple weeks, I was happily planting tomato seedlings in my new plot a half block from where we moved. It made me feel at home again.
Meanwhile, I kept hearing about Gateway Greening but didn’t really understand what the organization was. I did note our sign said the garden was established by GG in 1999– long before I moved here.
I got more involved in the Tower Grove East Community Garden, and that’s when I came to appreciate what a wonderful resource Gateway Greening is. I visited their headquarters and took the required course for garden officers. I attended their early spring conferences, where I learned community gardening techniques and met others who are just as passionate about urban gardening as I am. And, best of all, I discovered Gateway Greening’s volunteer services.
Frankly, we wouldn’t be where we are today–nor would we look as good–if it were not for the volunteers Gateway Greening has sent us. We’ve had folks from Minnesota who mightily struggled, and prevailed, in 90-degree weather under brutal sunlight; they weren’t used to such heat.
We’ve had seminarians and families who’ve helped us. We’ve had up to several dozen people–I call them worker bees–who have descended on our grounds, worked furiously in often very hot weather and left the place neat and clean. I must say the most impressive were the high school track team girls (can’t remember from where), who conquered deep roots that our gardeners hadn’t been able to budge. Yes, I have to say they definitely out-weeded the guys.
Then, late last year, Gateway Greening arrived with much-needed tools to refurbish our tool shed. What a gift! Now, of course, I hope to apply for a new arbor/trellis from them. When I have friends visit, I always give them a tour of the garden and explain about Gateway Greening, a wonderful umbrella organization of more than 200 urban community gardens.
Meanwhile, we’re determined to keep improving the garden. Thanks to Alderwoman Christine Ingrassia, the city installed new sidewalks and replaced ancient steps leading up to the garden this fall. We paid to have our 100-year-old plus retaining wall tuckpointed; it had been cracking and chipping.
Though the 2017 growing season may be over, winter is no time to sleep on preparing for your garden. One of the most important aspects of planning for spring is deciding which plants to grow. Below we provide recommendations from knowledgeable Gateway Greening staff so that your garden can thrive!
If you have not heard about the many benefits of perennial plants, consider this your wake up call. Perennials can reduce the amount of time spent planting in the spring and are often quite hardy.
Some great choices for St. Louis, according to our Garden Program Manager, Dean Gunderson, are:
Sorrel –A tangy green that kids love, sorrel is a perennial that thrives in the St. Louis region. It can be used as either an herb or green and is ready to harvest in earlyspring, making it a great way to start the growing season.
Asparagus –Though asparagus can take a year or two to establish, once it does it will produce delicious food for years to come.
Read more about edible perennials that grow well in St. Louis here.
Varieties That Thrive in St. Louis
Jackson Hambrick, Garden Project Manager at Gateway Greening, has a lot of experience finding varieties of common vegetables that thrive in St. Louis. Through trial and error, he has found that the examples below embrace the extreme temperatures and unreliable precipitation of the region.
Malabar Spinach –Though the name suggests otherwise, this plant is not actually a spinach. Unlike classic spinach, malabar spinach does quite well with the humidity and heat of summer in St. Louis.
Lettuce ‘Muir’ –“This is the most heat tolerant lettuce I have come across. It can easily handle the large temperature swings of St. Louis springs and can be grown under cover during the early summer,” Jackson said.
Missouri Pink Love Apple Tomato –If you are looking for a gorgeous tomato to add color to your garden, this variety is a great choice. It is a Missouri heirloom and when taken care of, it will thrive in the St. Louis region.
Try Something New
Roselle –Roselle is a species of hibiscus that is native to West Africa. It is used to make hibiscus beverages and preserves. While a perennial in warmer climates, in the St. Louis area it is
Storage Tomatoes –If you ever wish for home grown tomatoes long after the growing season, storage tomatoes are a perfect choice. When they are picked green, they will ripen over the course of weeks and can stay delicious for weeks beyond that, depending on the specific variety.
Okra –Though okra is a widely recognized vegetable, it is not always common in community gardens. It is a great choice for St. Louis because it loves our hot summers! It also produces beautiful flowers that can be used in arrangements.
Ground Cherries –If you are looking for a slightly sweet and low maintenance choice for your garden, ground cherries will fit the bill. They are in the same genus as tomatillos and could be mistaken for them because of the papery husks that they are covered in. They are great to mix in salsas and pies and also make a delicious jam.
Do you have a favorite plant that does not get enough love in the St. Louis region? Or have you been meaning to try something new but have not been able to plant it yet? Share with us on Facebook, Twitter or email! We would love to hear about your garden experiments and plans.
After reading several gardening blogs which enthusiastically endorsed potato towers in spring but never followed up to share how the towers had performed post-harvest time, the staff of Gateway Greening decided to put this technique to the test. Our goal was to see if potato towers are an effective method of vertically growing sweet potatoes as a way to maximize growing space in the home or community garden.
Limited Resources, Limited Testing
Although our staff originally planned to test this method using three towers of various heights and widths, we scaled the experiment back to create just one tower due to soil availability. (At the end of the day, expanding school and community gardens comes first. Experiments in theDemonstration Garden come second.)
The potato tower we constructed is close to six feet tall. Built around an irrigation tube (PVC pipe with holes drilled into it) and lined with burlap, Demonstration Garden intern Clara and volunteer Theresa filled the tower with thin, alternating layers of topsoil and compost. Next, small holes were cut into the sides of the tower at regular intervals for sweet potato slips to be tucked in.
Over the course of the summer, volunteers and staff carefully watered the tower by spraying down the burlap sides and also by using a hose to run water through the irrigation tube. Little by little, the slips began to flush out into vines and flourish.
Did it Work?
Although several sweet potatoes were harvested from the tower this fall, Garden Program Manager Dean Gunderson has decided to repeat this experiment again next summer. Technically the experiment was a success – but there was definite room for improvement.
When we constructed our potato towers, we made a fundamental mistake: we planted the tower with sweet potato slips shortly after it was constructed. Throughout the summer the layers of soil and compost settled significantly, damaging the delicate sweet potato slips and their root structures.
As a result, we harvested few sweet potatoes and they seemed to be quite small, as though stunted early on. Our volunteers also observed that all of slips planted in the lower half of the tower died, and suggested that the sheer weight of the soil above prevented the potatoes from establishing below.
Potato Tower Experiment Planning for 2018
In 2018, Demonstration Garden staff and volunteers will be repeating the potato tower experiment with the original (now settled) tower and a second tower that will be shorter in size for comparison. Keep an eye out for photos and updates next spring!
One of the challenges of growing food in an urban environment is not only finding a space to start a garden, but also clean soil to grow food in. As a result, Gateway Greening is always looking for new ways to make the most of our available space.
Last summer, Garden Program Manager Dean Gunderson decided to tackle the 45-degree angle trellis. The concept is fairly simple. Instead of using a shade cloth to cover and protect vulnerable cool season crops, he would build a trellis and grow a vining plant across it. If it worked, the cool season crops would be protected by the leaves of the vine above, and would result in twice the harvest amount from the one growing space.
To start, Dean and long-time volunteer John Newman teamed up to design and build the trellis using spare lumber and cattle panel.
“The hardest part [of building the trellis] was figuring out how to stabilize the flexible cattle panel and how to attach the legs to it since it was narrower than our wide [garden] beds.” – Dean Gunderson, Garden Program Manager.
In the end, Dean and John built a wooden frame to support a single length of cattle panel and attached wooden legs to the sides for support. By varying the lengths of the wooden legs, they were able to create the desired 45-degree angle.
Planting for Harvest & Feedback
In the spring cabbage, broccoli, and other cool season crops were planted in the raised bed below the trellis. These are crops that often die off as summer arrives, and would be effective indicators of how well the experiment worked. A few weeks later, volunteers planted four tromboncino squash plants at the low end of the trellis to be the “shade vine.”
This experiment was particularly fun to watch. Unfortunately, the squash’s growth did not take off until summer heat hit, meaning it was not able to provide significant protection for the spring cool season crops. However, once the heat hit the tromboncino squash plants grew at staggering speeds, creating a shady nook in no time. More than one Saturday volunteer and staff member observed that it was a perfect place for a yoga mat and a nap!
Although it did not provide adequate cover in spring, the squash was more than able to provide cover for fall cool season crops. As a result, volunteers were able to plant carrots, cabbage, and a few other fall crops earlier than we typically would. The harvest from these crops was smaller than anticipated, but we suspect that was due to a lack of sunlight – the tromboncino squash vines really took off!
Using vining plants in place of shade cloths can be an effective method of maximizing space while still protecting cool season crops, however, it does require extra management. Choose vining plants that will grow and provide shade at the time you need it most. For some of the more aggressive growers, make time to prune away excess vines to permit adequate sunlight to reach crops below.
Fun fact: Saturday volunteers harvested 263.45 pounds of tromboncino squash from the trellis experiment this summer. That’s 263.45 pounds harvest in just three months!
One of the most common phrases I hear from volunteers helping in the Demonstration Garden on Saturdays is: “I wish I could garden at home, but I live in an apartment.” On the other hand, we have several older individuals who tell us they “miss gardening but I just can’t bend over to pull weeds anymore.”
At Gateway Greening, we believe that gardening should be accessible to everyone so when an opportunity to test a new container gardening product came up, we took it!
Beginning the Garden Soxx Experiment
Thanks to a donation byEco Constructors, a local business that specializes in sustainable, low-impact erosion control products, Gateway Greening received several Garden Soxxto test. These short tubes are made using a special mesh filled with organic growing medium fromSt. Louis Composting,and weigh about 30 pounds each when dry. Our goal was to see if Garden Soxx could be an effective method for container gardening in urban spaces.
For our Garden Soxx experiment, we placed several tubes along the edge of a brick patio in the Demonstration Garden. By doing so, we hoped to create conditions similar to an apartment balcony or concrete patio. One placed, staff and volunteers planted a small variety of crops commonly found in both home and community gardens: chives, purple basil, three different varieties of hot peppers, pole beans, and radishes.
Planting was a breeze. Using a small pocket knife, we made holes in the mesh fabric that were just big enough for our seeds and seedlings to fit inside. For the seedlings, we scooped out a small amount of growing medium to make space for the root systems. The extra medium was gently packed around and over the seedling’s roots to stabilize and protect the plant while it got established.
Throughout the summer volunteers and staff vigilantly watered the plants several times a week using a garden hose or watering can. Thanks to the mesh tube, we saw very little soil run-off and overwatering was impossible. Excess water simply ran out!
Before long, we started harvesting a small amount of produce from the chives, basil, and each of the hot pepper plants. Unfortunately, the resident rabbits made a feast of our pole beans shortly after germination, and our fall crop of radishes did not germinate – likely due to dry conditions.
Did it Work?
Overall, the Garden Soxx were an effective method for container gardening in an urban space, but they did present a few challenges as the season wore on.
Firstly, that the Garden Soxx needed almost constant watering during dry spells and the height of summer heat. With their sunny location and lack of wind protection on the edge of the patio, the Garden Soxx were prone to drying out quickly which stressed the plants. The second challenge was that the Garden Soxx needed a few applications of organic fertilizer throughout the summer to support ongoing food production.
Garden Soxx would be ideal for someone looking to grow annual vegetables or flowers with shallow root systems on a balcony or raised patio. Gardeners using Garden Soxx should be prepared to water regularly, and add small amounts of fertilizer as needed. Want to check out Garden Soxx first hand? Stop by the Carriage House during the growing season in 2018!
This is the third in a series of articles about the challenges gardeners and farmers have faced while working in an urban area, as well as the solutions they have come up with in the face of these issues. Read the previous posts from the series here and here.
A Skeptical Gardener
Allison Reed was skeptical about joining a community garden. Mostly because she hates bugs. Especially mosquitoes.
But when Florida Cargill, garden leader of House of Living Stone community garden, asked her if she wanted a garden bed two years ago, Allison decided to give it a try.
She still hates bugs, but has found an enjoyable hobby in community gardening. She even calls it one of the most relaxing hobbies that one can have. Planting citronella plants in her garden beds has also helped keep the bugs off of her when she comes to tend to her plants during summer evenings.
House of Living Stone
House of Living Stone community garden was founded in 2011 and is part of the First Baptist Church of Webster Groves. The name, which often draws interest, is based on the bible verse 1 Peter 2:5. According to Florida, the verse is about Christ talking to Peter about how believers are the living stones of a church.
The garden’s relationship with the First Baptist Church of Webster Groves means that it is used quite often for bible studies and events. It functions as a community space where members of the church can meet while enjoying the striking beauty of the garden.
And striking it is. When I first visited the garden on a September evening, the sun was just beginning to cast light through the trees. The garden, which is set atop a steep hill, features a variety of flowers and a small orchard and seems to welcome visitors in with its many benches and picnic tables.
Children in the Garden
One of the unique components of the House of Living Stone community garden is the emphasis on making the space a welcoming place for children.
At one edge of the garden, there is a patio area made of many painted concrete pavestones. The pavestones were painted by children of First Baptist Church of Webster Groves and feature bright designs, names, and references to biblical stories. The paintings were designed to celebrate the church’s 150th anniversary and several of the pavestones have images of large birthday cakes as a result.
The garden also has a bed for children to plant various vegetables and flowers. This past summer, it held sweet potatoes and marigolds.
Florida and other garden members work hard to ensure that the garden is a place where children can come to play and enjoy its many wonders.
Problems and Solutions
The garden is undoubtedly a haven, which is made obvious as soon as you climb to the top of the hill where it sits and take in the view around it. But, like many community gardens, it experiences both environmental and involvement challenges.
This past summer, the garden’s biggest problem has been moles and groundhogs. The gardeners tried building fences made of chicken wire around their garden beds. The makeshift fences worked at first but half-chewed sweet potato leaves made it obvious that the problem required more action. Some of the gardeners eventually built a cage made of chicken wire around their garden bed. This prevented any critters from climbing in and making a meal out of growing vegetables.
House of Living Stone Community Garden, like many others, has also experienced periods of low membership and engagement.
Florida said that she keeps an eye on the garden beds and reaches out to members to ask them if they need anything if it seems like they are having trouble making it to the garden.
She also credits continued membership to the enthusiasm of the pastor of First Baptist Church of Webster Groves.
“He always tells people about the garden and how to get involved and makes sure to announce events there at church meetings,” Florida said.
The garden’s strong connection to the church has meant that excess produce has a convenient place to be donated. The church has a food outreach ministry that provides supplemental meals to those in need.
The garden is a unique entity. A place of calm in a city that teems with life. It provides both respite and a place to challenge oneself.
“Planting something new every year is fun. I just like to see if I can grow something different,” Allison said.
I entered the garden stressed from traffic and honking horns. But as I walk down the hill the garden sits on, the light slanting low, I feel a sense of calm that was not there before.
Written by Mallory Brown, Communications & Fundraising AmeriCorps VISTA
If you stopped by the Demonstration Garden this spring, you may have met Myra Rosenthal, a long time Gateway Greening volunteer and Garden Leader of the Garden of Eden at the JCC. Recently, we caught up with Myra to learn more about the Garden of Eden’s unique mission: providing her local food pantry with fresh garden produce.
“You know, it wasn’t difficult [to start a garden] and it evolved organically (pardon the pun). Many people have gardens in their homes and bring excess produce to the pantry. For years my husband has always taken his extra tomatoes, peppers, and cucumbers there. Jewish congregations in the St. Louis area have donation bins solely for the purpose of collecting food for the pantry.” – Myra Rosenthal, Garden Leader at the Garden of Eden
Founded in 2011 with the goal of providing fresh produce to the local Harvey Kornblum Jewish Food Pantry, the Garden of Eden has grown considerably from its humble beginnings.
Open four days a week, the Garden of Eden is located on a corner of the St. Louis Jewish Community Center property and currently has more than 4,000 square feet of growing space in the form of raised planting berms and beds. A portion of the garden is reserved for the use of nearby Covenant Place residents, many of whom are immigrants or refugees.
With the combined effort of long-time gardeners, individual and group volunteers, and even a few cheery day camp participants, the Garden of Eden was able to grow and donate more than 3,700 pounds of food to the Harvey Kornblum Jewish Food Pantry in 2016 alone.
Harvey Kornblum Jewish Food Pantry
Started in 1991, the Harvey Kornblum Jewish Food Pantry, a program of Jewish Family & Children’s Service, originally operated out of a single room on a shoestring budget, serving no more than 40 families. Since then the food pantry has grown considerably. Today it is a designated USDA food pantry affiliated with the St. Louis Area Foodbank and Operation Food Search, and serves more than 6,500 people each month, making it one of the largest food pantries in the region.
During a recent visit to the food pantry to learn more about how community gardeners can support their local pantries, Gateway Greening staff Erin Wood and Mallory Brown were deeply impressed by the Harvey Kornblum Jewish Food Pantry’s commitment to alleviating hunger among people of all faiths and backgrounds. The staff and volunteers of the pantry make every effort to accommodate special dietary needs, providing kosher, halal, gluten-free, and diabetic friendly options for their guests as much as possible.
When asked how the Garden of Eden decides what to grow in the garden each year, Myra’s response was candid: “Well, we got smart. Eventually. When we first started, that is, in our first year, we went to a local gardening store and we thought, ‘Oh, this plant looks good. We’ll buy it.’ ‘Oh, look, this is interesting. Let’s get it.’ ‘Oh, this herb is soooo cute. We’ll grow this.’ Then somewhere in the middle of the summer, I remember thinking, ‘Is that what the clients of the food pantry want?’ So the next time I went to the pantry I asked. I was stunned when I was told the clients in the pantry had no use for herbs. They wanted simple, sustainable food. They didn’t want anything fancy. That’s when I learned we don’t grow what WE want. We grow what THEY, the clients of the food pantry, want.”
Visiting the Harvey Kornblum Jewish Food Pantry is much like visiting a corner grocery store, as the pantry has moved to a “Client Choice” model. Using this model, guests are encouraged to explore the items and select foods which their families will use at home, up to a certain amount based on the number of people in their household. Judy Berkowitz, Director of the food pantry, explains that this model is more flexible than the traditional ‘bagged’ method, allowing individuals to meet their dietary needs while still embracing differences in food culture among their diverse guest base.
Myra shared that it is sometimes challenging to grow for such a diverse community, but most of the time – it isn’t. Despite not being familiar with crops like okra and collard greens, Myra chose to grow them because they went over well with the clients. “We are a multicultural country anyway and we should try other’s foods. Come to think of it, the clients at the food pantry are multinational. Some are from Asia, Russia, the Ukraine, and the Middle East. What’s odd or unusual to us may not be to them and they gladly take.”
Community Garden Challenges
When asked about challenges faced by gardening, Myra states: “Gardens are gardens. I’ve never met a productive vegetable garden that looks like a set for a magazine or a tv show. Even the vegetable garden in Orange Is the New Black looks a zillion times better than ours. And there’s a dead body buried in it! I have had to deal with dismissive comments of people who think we should look weed free, lush and beautiful. I think we spend an inordinate amount of time on weeding and other tasks so that the garden looks at least decent to ordinary passersby. But, then, to be fair, we chose not to have a fence. That was deliberate. In the Bible, farmers are commanded to leave part of their fields for the poor to glean. We do the same.”
Beyond the weeds, the Garden of Eden faces other challenges that many St. Louis community gardens can relate to: the struggle to find continuous funding, engaged volunteers and new garden members, as well as materials being stolen or vandalized. And perhaps the most devastating of all – the occasional crop failure.
Guide to Growing for Food Pantries
Interested in sharing the bounty from your personal or community garden with a local food pantry? Myra shares a few insights:
Food pantries are as varied and unique as the communities they serve. Some will have refrigerators and freezers available for storing excess food, and some will not. Although most will take fresh foods that will last for at least a few days, some pantries will only accept boxed and canned goods.
Open Hours: Learn when the food pantry is open, and call ahead to see when they accept donations. Many rely on volunteers and may only have the capacity to accept and process your gift on certain days.
Visit your food pantry! Knowing how a pantry operates, and what its specific needs are, will empower you to make informed decisions about what will and will not be helpful to the food pantry.
Always respect the privacy of the guests of the food pantry. Ask the food pantry staff if there are any guidelines you should be following when making a donation.
People who are food insufficient are reluctant to try new items, and many do not have measuring cups, baking equipment, or easy access to the internet to search for recipes. When possible, keep your food donations simple and basic. When growing for a pantry, always ask what foods will be most helpful.
Always clean the food before making a donation! Food pantries have a lot of work to accomplish and often have limited manpower to do it all. Food safety is paramount when providing food for others, and providing clean food ensures it ends up on the shelves quicker.
Call ahead and let the food pantry know that you are harvesting for them or plan to make a donation on a certain day. This simple courtesy is anything but, as it allows the pantry to make changes as needed to meet the needs of its guests.
Matt Even, Outreach Coordinator of Gateway Greening, loves trying to grow new and exciting plants at the Demonstration Garden. He wants to use the space and lack of pressure to produce food that growing plants at the Demonstration Garden gives to try innovative things that might flourish or fail. During Spring 2017, he planted uncommon herbs to test what is possible to grow in the St. Louis region.
Tulsi (Holy Basil)
Tulsi is an herb that is native to India and grows best in tropic and subtropic climates. In its native habitat it is a perennial, but it can be grown as an annual in Northern regions, such as St. Louis. Tulsi is largely grown for its medicinal properties, culinary attributes, and uses in Hindu religious ceremonies. Many people drink it in a tea, which is high in antioxidants and said to support the immune system. Matt said that the Tulsi is the Demonstration Garden is doing quite well and that he will probably plant it next year. It’s definitely a good choice for St. Louis gardens.
For more information on how to grow Tulsi, click here.
Sweetgrass is also an herb used in ceremonial and religious contexts. It is native to North America and Europe and is especially significant for many Native American tribes as a result of its use as incense. Sweetgrass is a perennial herb that can produce extraordinary yields when cared for correctly. It is traditionally harvested, dried, and then braided, which is the form it is usually found in stores. The plant has a vanilla-like aroma that is especially strong when burned. Like Tulsi, the sweetgrass that was planted in the Demonstration Garden has grown very well and would be very appropriate for St. Louis gardens.
For more information on how to grow sweetgrass, click here.
Angelica has been commonly used as a flavoring agent in many types of liquors, such as gin and vermouth. It is native to Europe and prefers cool climates as it is a heat-sensitive plant. The angelica in the Gateway Greening Demonstration Garden has not done as well as it could have because of the hot summers that St. Louis typically experiences. Unlike many herbs, Angelica actually prefers moist soil, which is something to keep in mind if the plant makes its way to your garden. It is definitely a plant that requires extra attention in the St. Louis region. Unless you have the time to devote to caring for Angelica, it should not be your top choice for planting.
For more information on how to grow angelica, click here.
A perennial edible that has a flavor between celery and parsley, Lovage is a tried and true choice for St. Louis region gardens. It also has the unique benefit of needing little attention and being one of the first plants to come up in the spring. In its native Europe, it has long been used to flavor food and beverages. Lovage was historically grown for its medicinal properties as it was said to help with stomach pains and fevers.
For more information on how to grow lovage, click here.
Though the growing season is not yet over, Matt Even is already excited to see what he can grow next year. He said that next year he wants to try to grow plants such as lemongrass, Spanish tarragon, epazote, and lemon verbena. Matt said that he thinks the best thing about growing less common plants is the excitement of trying something new and seeing whether it works or not.
From the herbs he planted this year, he would recommend that St. Louis gardeners try growing lovage or sweetgrass, as both have thrived in the Demonstration Garden this spring and summer.
Interested in seeing these plants in person? Come to the Gateway Greening Demonstration Garden on Saturday mornings to check them out!
Over the years, many people have expressed their concern over Gateway Greening’s decision to use treated lumber for gardening purposes. Today, we would like to take a moment to address those concerns and to provide information on the different types of treated lumber available in general and the materials Gateway Greening uses in particular.
What is Treated Lumber?
Treated lumber is wood that has had compounds added to it in order to prevent wood-decaying organisms (bacteria, fungus, and insects) from decomposing the wood (1). Treated lumber is typically “pressure treated,” meaning high pressures are used to force preservative compounds into the wood. This provides more protection long term than a simple surface coat would.
Unlike untreated lumber, which will quickly start to break down when left exposed to the elements and wood-decaying organisms, treated wood remains usable for many years (1).
The History – CCA Lumber Treatment
Throughout much of the 20th century, lumber companies relied on a lumber treatment that utilized Chromium, Copper, and Arsenic (CCA). Studies found that arsenic could be leaching into soils that came into contact with the CCA treated lumber. However, arsenic is a compound found naturally in soils and the leaching was considered to be within safe limits.
Although CCA treatments were not found to pose an “unreasonable risk to the public” (2), the EPA decided to reduce Arsenic exposure, (3) (2) leading companies to cease manufacturing CCA lumber for residential use (4) in December of 2003.
After the 2003 EPA decision1, horticulturally focused authors and agriculture enthusiasts began to warn gardeners of the risk of using CCA treated lumber for gardening purposes.Similarly, Gateway Greening does not use CCA treated lumber for its gardens, urban farm, or other civic greening projects.
Lumber after CCA
In the aftermath of the 2003 EPA decision1, the lumber industry developed several alternative treatments which provided the same level of decay resistance as CCA treated lumber, without using arsenic or chromium.
Gateway Greening uses the Lifewood brand of lumber which is treated with micronized copper azole. According to the Missouri Department of Agriculture and the USDA’s Forest Products Laboratory, Lifewood’s copper azole treatment “is comprised of 96-percent copper and 4- percent tebuconazole,” a fungicide (5) (6).
The Lifewood brand was the first lumber treatment brand to be certified by the Scientific Certification System (SCS) as an “Environmentally Preferable Product,” meaning that it meets qualifications for this environmental certification based on an independent life cycle assessment (7). (The qualifications to receive this certification can be explored on the SCS’s website (8)). Products that receive Environmentally Preferable Product certification have been independently assessed to verify that the product is better for the environment than the prevailing, similar products (8)). Products that receive Environmentally Preferable Product certification have been independently assessed to verify that the product is better for the environment than the prevailing, similar products.
The copper azole lumber treatment is considered to be a safe choice for raised vegetable beds. University of Missouri Extension states that copper azole is as safe for raised beds as a similar type of wood treatment, known as ACQ, and confirms, “exposure to copper from contact with ACQ-treated wood is not expected to have adverse effects on the health of adults or children” (9).
While it is a known fact that some amount of copper and the fungicide tebuconazole will leach from the lumber into the soil over time, this happens at such low levels it is not considered dangerous. In fact, copper azole treated wood is actually suggested by Iowa State University Extension for use in raised vegetable beds (10).
The use of Copper in Lumber Treatments
Copper is a common component of treated lumber because of copper’s antifungal properties (2)(9). Copper’s antifungal nature helps to prevent fungus from colonizing and decomposing wood, allowing treated lumber to last longer than untreated lumber.
Although there is a fair amount of copper in Lifewood brand lumber, the life cycle assessment of the product states,
Wood products treated with the Osmose MicroPro process result in the release of 90% to 99% less copper into aquatic and terrestrial environments when compared to standard treated wood products. The very small amount released bonds readily to organic matter in the soil and becomes biologically inactive, thus effectively eliminating eco-toxic impacts (11).
In short, although there is more copper in the copper azole lumber it actually leaches less copper into soil than the CCA treated lumber over time. The small amounts of copper that do leach are soon trapped in the soil, meaning it cannot be taken up by vegetable plants.
Researchers at Pennsylvania State University have also studied copper leaching while studying CCA treated lumber for use in gardening, and discuss some of their findings in a publication. When discussing potential leaching of arsenic (As), chromium, (Cr) and copper (Cu) from the old CCA lumber, the researchers found that:
When trace elements such as these three are added to soil, most of what is added is not available for plant uptake. Chromium and copper are bound very strongly by soil particles, especially by soil clays and organic matter. They are most strongly bound in near-neutral soils (pH 6–8) and become more soluble in acidic soils (pH less than 5). As a result, Cr and Cu tend not to move in soil, and only a small fraction of what is added to the soil can be taken up by plants (2).
The publication later emphasizes this by stating that gardeners can avoid potential plant uptake of these nutrients by “Maintain(ing) soil pH in the near-neutral range (pH 6–7). Solubility of Cr and Cu is greatly reduced in neutral soils,” and, “Maintain high soil organic matter levels by adding compost or manure. Organic matter strongly binds As, Cr, and Cu and thus reduces their availability to plants,” two things that gardeners typically do as part of their regular gardening efforts (2). Even if some copper is absorbed by plants, Pennsylvania State University states that:
…the human body can tolerate relatively large intakes of Cr and Cu and is also able to excrete excess amounts of these metals. Furthermore, plants are less tolerant of Cr and Cu than humans are. This means that Cr and Cu would kill plants before plant tissue concentrations could get high enough to cause a chronic toxic effect in humans from eating the plants (2).
In summary, research shows that although the copper azole treatment is 96% copper and is known to leach into the surrounding soil:
Leached copper is quickly bound up in clay and organic matter so that it is highly unlikely that garden plants would absorb it.
Copper is far more toxic to plants than humans, meaning that garden plants would die before carrying harmful levels of copper to the dinner table.
Copper is actually an essential nutrient for humans, and our bodies are able to absorb the needed amount, then safely pass any excess.
The use of Fungicide in Lumber Treatments
Like copper, the fungicide tebuconazole is added to copper azole treated lumber in order to prevent fungus from rotting away lumber. More specifically, the fungicide is needed to control certain wood-rotting fungus that copper cannot kill (12).
According to a study done for the European Union, “An accumulation of tebuconazole in soil is not anticipated when tebuconazole is used as a wood preservative” (13). It further states that, “Tebuconazole has a low mobility potential” (13) meaning that the fungicide is unlikely to leach from the treated lumber and into the surrounding garden soil to any significant degree.
Two different studies where tebuconazole was sprayed on the soil surface found that it was readily locked up by the soil during experiments, with most of it staying within 2” of the surface (14). Further research revealed that tebuconazole’s mobility in an agricultural field (as opposed to a controlled laboratory setting) is similarly immobile, though when organic matter is added it becomes more mobile in the soil with most of it remaining within 1-4 inches of the soil surface (15). However, the organic matter also speeds up tebuconazole’s decomposition in the soil so that it has a half-life of only 8-12 days when soil has added organic matter (15).
Although these results are not a perfect analogy because the studies relied on applying tebuconazole directly to the surface of the soil rather than being bound to wood, they do provide a fairly accurate idea of the movement and leaching capabilities of the tebuconazole fungicide used in treated lumber.
Lumber used by Gateway Greening
The treated lumber Gateway Greening uses to build raised beds is only treated with copper and a fungicide tebuconazole. This type of treated lumber results in far less leaching than alternative lumber treatments. The components that do leach are mostly locked up by clay and organic matter in soil meaning it is harder for the plant to absorb it.
Copper becomes even harder for plants to absorb when the soil is a neutral pH, a goal most St. Louis gardeners strive for in order to grow the best possible vegetables.
It is also harder for plants to absorb copper if organic matter (compost) is added, which gardeners in the St. Louis region typically do in order to promote healthy vegetable production.
If a plant does absorb copper, the plant would die before it could absorb enough to be dangerous for human consumption. Even if someone were to eat a plant that has absorbed copper, and the copper had moved into the edible parts of the plant, the human body is adapted to get rid of excess copper – an essential element in the human diet.
Lumber treated with tebuconazole is not expected to release worrisome amounts of the fungicide into the soil given that it is found in the wood and in the soil immediately next to it only. Even when the fungicide was sprayed on the soil surface during testing trials, most of the fungicide only moved 1-4” down when soil was properly amended. However, amendments sped up the breakdown of the fungicide.
Why not use Untreated Wood or Cedar?
Many ask about “natural” alternatives to treated wood, or ask why we do not just use untreated wood or naturally rot-resistant wood like cedar. While we technically could use “natural” alternatives, there are several key reasons why Gateway Greening recommends the treated option instead.
The main reason we do not use untreated lumber is because the most readily available untreated lumber is pine, which is a softwood and rots very quickly. Researchers at the University of Georgia report that, “pine has almost no resistance to rot or insects and has a very short life when used in direct contact with soil” (16).
Untreated hardwoods like oak are more rot-resistant but have their own drawbacks. Firstly, only the heartwood of lumber is resistant to rot, with the sapwood of even rot-resistant species being just as susceptible to rot as the sapwood of the more rot-prone softwoods (1). So for woods like oak to be longer lasting than pine you need to make sure you are buying lumber that doesn’t contain sapwood. It is also generally difficult to find those harder woods in sizes good for raised beds and they are significantly more expensive than treated pine, and “based on most research, provide only slightly more rot and insect resistance than pine” (16).
By far the favorite wood material for those trying to avoid all treatment processes is western red cedar. Although cedar is a great wood if you are trying to avoid all treatment it is still not ideal for Gateway Greening’s school and community garden programs. The biggest reason is cost. Cedar boards usually cost four to five times more than treated pine. This much greater cost would reduce the number of gardens Gateway Greening currently serves by 75%.
In addition to the upfront cost, despite cedar’s rot-resistant nature, it still has a shorter lifespan than treated lumber when in contact with soil (17). Researchers at the University of Georgia report that fence posts made of treated pine can last up to twice as long as western cedar. Even comparing the best case for cedar to the worst case for treated lumber, the treated lumber still lasts longer (17). Although a fence post isn’t exactly the same as a raised bed it does give a good idea of how the different woods will respond to being in constant contact with soil and regional weather conditions.
We hope that we have been able to address and alleviate many of the concerns gardeners often voice at the use of treated lumber in local community garden projects. If not, please do not hesitate to reach out to our staff to ask questions!