gardening

Natural Pesticide Issues

pink roses in a natural garden in West Hartford
Roses in a garden in West Hartford. Photo: Max Pixel

As the gardening season gets underway, lots of homemade weed-killer “recipes” are cropping up on social media, usually containing some combination of vinegar, Epsom salts, and Dawn dishwashing soap. These are often accompanied by a comment such as “no need for pesticides or herbicides!” It may feel good to use familiar household items to control pests and weeds in your garden, but it’s important to understand the science behind such mixes – and the potential risks.

First and foremost, these mixtures ARE pesticides or herbicides. They are intended to kill a pest, in this case weeds.

Now, let’s look at the science:

Vinegar is an acid. At the right concentration, it damages by burning any part of a plant it comes in contact with. If the plant is in the ground, it does NOT get the root; many plants will grow back. It is non-selective, meaning it will damage any plant it touches, including desired ones. Household vinegar is 5% acetic acid; to be effective on anything other than tiny seedlings the concentration needs to be at least 10%. Horticultural-grade vinegar is 20% and can carry a “Danger – caustic” signal word, which is stronger than many other herbicides on the market.

Salts work by desiccating plants – again, all parts of the plant it touches. Salts, however, build up in the soil and can harm desired plants nearby. Since most homemade recipes need repeated application to be effective, the salts will build up. Epsom salts are touted because they contain magnesium instead of sodium, but too much magnesium will interfere with phosphorus uptake.

Dawn detergent is not a naturally-occurring substance. It, like any soap, is used as a sticker agent, helping the other materials stay on the plant longer. It contains methylisothiazolinone, which has acute aquatic toxicity and 1,4-dioxane, which is a known groundwater contaminant with carcinogenic properties.

These may be do-it-yourself recipes, but they definitely are not natural.

An additional issue with home recipes is the variability of the mix. Many don’t even have specific measurements. Also, because home remedies are often perceived as “safer”, a person may choose to increase the concentrations, changing the potential environmental risk.

Many of these recipes do indeed kill – or at least reduce – weeds and unwanted vegetation. But they also have collateral impacts, some of which may be significant.

The garden center shelves have changed in the last several years. There are now many naturally-derived pesticides on the market, which have been tested for effectiveness, are labelled as to their environmental impact and deliver a consistent product every time. They generally are safer to use and pose less environmental risk than many of the older synthetic materials – the same goal of homemade mixes. Look for products that are OMRI certified. The Organic Materials Review Institute is a nonprofit organization that provides an independent review of products, such as fertilizers and pest controls that are intended for use in organic production.

For more information, please contact the UConn Extension Master Gardener Program. Find the location nearest you at https://mastergardener.uconn.edu/ or email Sarah.Bailey@uconn.edu.

Article by Sarah Bailey, State Coordinator, UConn Extension Master Gardener Program

Join us for a Garden Party

Garden party invite graphic with logo

Please join the UConn Extension Master Gardener Program for an exclusive Garden Party, hosted by Master Gardener Susan Saint James.

Saturday, June 15, 2019
11:00 a.m. – 1:30 p.m.

Susan Saint James Home*
Litchfield, CT

Speaking program includes:

Susan Saint James
Dean Indrajeet Chaubey of UConn CAHNR
Amy Chesmer, CAHNR ‘94

Tickets:
Individual – $100 
($60 tax-deductible)

Table of 10 – $1,000 
($600 tax-deductible)

Register now: http://bit.ly/UConnGardenParty

Plant Sales on May 18th

Fairfield Plant Sale flyer Windham Plant Sale flyer

Gardeners: Join us for a plant sale on Saturday, May 18th. We have one on each side of the state: Bethel and Brooklyn. We’ll be at the Windham County Extension Center in Brooklyn on Saturday, May 18th from 9 AM until 2 PM. The plant sale at the Fairfield County Extension Center in Bethel is from 9 AM until 1 PM. We’ll have perennials, annuals, tomatoes, vegetables, herbs, and house plants. You can bring garden problems to be diagnosed, and purchase soil test kits. Email windham@uconn.edu or fairfield@uconn.edu for more information.

Job: New Haven County Master Gardener Coordinator

Position Description
Master Gardener County Coordinator New Haven County

Master Gardener logoThe UConn Extension Master Gardener Program is seeking applications for the position of Master Gardener New Haven County Program Coordinator. This is a 16‐hour‐per‐week position and is a temporary, six‐month appointment. Renewal is optional pending coordinator review and availability of program funding.

Responsibilities include but are not limited to: provide leadership for the base county Master Gardener program. Successful candidate will coordinate staffing of program mentors, volunteers and interns; coordinate and assist with annual classroom portion of the program; work with UConn Extension center/ county‐based faculty and staff, as well as university‐based faculty and staff as needed. Will also need to work with allied community groups and Extension partners such as the CT Master Gardener Association and Extension Councils; train and supervise interns in the Extension center when classroom teaching is completed; arrange and conduct Advanced Master Gardener classes each year; create, develop and coordinate outreach programs and projects in the county. They will prepare annual reports on program activities, impacts, incomes, outcomes (number of clientele contacts); and communicate effectively with the state coordinator, other county coordinators, center coordinators and support staff.

Preference will be given to candidates who are Certified Master Gardeners, or with a degree in horticulture, botany, biology or equivalent experience. Interested applicants should possess strong organizational, communication and interpersonal skills and be able to show initiative. They should be able to demonstrate experience in working collaboratively as well as independently, and be willing to work flexible hours including some evenings and weekends. Must be familiar with Microsoft Office. Volunteer experience is desired. Monthly reports shall be communicated to the state coordinator and topical information may be shared with others as requested.

Submit letter of application, resume and names of three references to:

Sarah Bailey, State Extension Master Gardener Coordinator at sarah.bailey@uconn.edu Please put Master Gardener Coordinator Position in the subject line.

If you are unable to use email, you may send it to:

Sarah Bailey
State Extension Master Gardener Coordinator University of Connecticut Extension
270 Farmington Ave, Suite 262
Farmington, CT 06032

Screening will begin immediately.

Celebrate 40 Years of the UConn Extension Master Gardener Program

Master Gardener banner photo
UConn Extension’s Master Gardener Program is celebrating 40 years of transforming academic research into practical gardening skills and techniques that everyone can use. The program sprouted in 1978 from the roots of the founding program at Washington State University. The program instructs participants in science-based horticulture practices and garden management, after which students apply their knowledge by engaging in community education, including lectures, educational displays, demonstrations and plant clinics, and various outreach projects throughout Connecticut.

Nancy Ballek Mackinnon of Ballek’s Nursery and Nancy DuBrule-Clemente of Natureworks are both presenting at a 40thAnniversary Celebrationof the UConn Extension Master Gardener Program on Monday, November 12thfrom 5:30-7:30 PM at the Pond House Café in West Hartford. Tickets are $75 per person and includes the presentations, small bites, door prizes, and a $50 donation to the UConn Extension Master Gardener program. The goal is to raise $40,000 to celebrate 40 years of wonderful work through several initiatives.

“We are marking the occasion in a few ways, but we’re really using the moment to look ahead to the next forty years,” says Sarah Bailey, state coordinator and Hartford County coordinator for the Master Gardener Program. “We love what we do and want to continue helping people of all ages learn and discover the joys of gardening and the natural world.”

Master Gardener’s outreach efforts are unique to each county and help meet local needs, often providing food to soup kitchens, food banks and residents living in food

students in garden
Nathan Hale students care for a garden bed.

deserts. UConn Extension Master Gardeners predominately work in community and school gardens and on farms and wildlife management areas, teaching crop selection and management practices to children and adults. In Pomfret, Windham County Master Gardeners care for People’s Harvest, a 15,000 square foot community garden that produces vegetables for area soup kitchens. People’s Harvest is popular with youth groups in the region, who learn about sustainable agricultural methods and food security from the volunteers. At Camp Harkness in Waterford, Master Gardener interns and volunteers practice horticulture therapy with adults with disabilities. Master Gardeners frequently attend farmers’ markets, fairs and other local events, eager to share their knowledge with the public.

Along with the certification process, the program offers Garden Master Classes, which allow further educational training. These classes are also open to the public,

providing instruction on gardening and a variety of related topics. The impact of their work has increased over time. In 2017, 574 Master Gardeners completed a total of 33,609 hours of service to communities and residents, compared to 23,500 hours in 2013. The restructured certification class debuting in January aims to create an even more robust and diverse group of Master Gardeners.

“The Master Gardener Program was founded to meet public need and encouraged individuals to participate. We’re continuing those traditions by growing as our audience changes,” says Bailey.

Tickets for the 40thAnniversary Celebration are available at http://s.uconn.edu/4hcor by contacting Amber Guilllemette at Amber.Guillemette@uconn.eduor 860-486-7178. To learn more about the UConn Extension Master Gardener program visit MasterGardener.UConn.edu.

Text by Jason Sheldon for UConn Extension

Open House with Fairfield County Master Gardeners in Bethel

Craft Fair and Open House Celebrates the 40th Anniversary of the UConn Extension Master Gardener Program

 

Date: Saturday, October 6, 2018

(rain date Saturday, October 13)

Time:9:00 a.m. to 3:00 p.m.

Where: Fairfield County Extension Office and Grounds

67 Stony Hill Road (Route 6), Bethel, Connecticut

 

vegetable gardenThe UConn Extension Master Gardener Program is celebrating 40 years as the premier example of a Master Gardener Program in the United States with a craft fair and open house. This outdoor event is free and open to the public. Expert Master Gardeners will give tours and demonstrations, and answer gardening questions. Vendors, many showcasing the creative endeavors of our Master Gardeners, will be offering a variety of gardening and nongardening crafts and goods for sale to benefit the UConn Extension Master Gardener Program.

The day will feature:

Tours and demonstrations

Walking tour and talk at the Extension Demonstration Vegetable Garden.

An 80-ft. by 100 ft. Demonstration Vegetable Garden on the Fairfield County Agricultural Extension Center site, built and maintained by Master Gardener mentors and interns, is used to teach the importance of current best practices in gardening and horticulture, and also donates its weekly harvest to local food pantries.

Composting Demonstration

Learn how you can make and maintain your own backyard compost with easy to build bins and a few simple steps.

Invasive Plant Guided Walk

Learn to spot the invasive plants trying to take over Connecticut’s gardens and natural areas. Find out which plants are considered invasive and why, and how they got here. Learn design alternatives for these aggressive invaders.

Information booths

Master Gardeners

Meet our Master Gardeners! Get answers to your questions about your gardens, lawns, trees, plants and insects. Learn how you too can become a Master Gardener.

All About Composting

Master Composters answer questions about backyard and worm composting, explain why it is important to reduce the waste sent to landfills, and how individuals and communities benefit from making compost.

Connecticut Agricultural Experiment Station/UConn Forest Pest Education

Learn about the Asian Long-horned Beetle, Emerald Ash Borer, and how Connecticut is battling these and other threats to our trees and forests.

Craft fair

As of this writing vendors will be offering for sale:

  • Vintage costume jewelry
  • Natural-dye yarns and scarves
  • Alpaca wool and products
  • Botanical stationery and notecards
  • “White Elephant” table of gardening and other items
  • Used gardening books
  • A specialty rake
  • Tillisandia’s glass globes and fairy gardens
  • Painted rock art
  • Hand-crafted wooden bowls and other items
  • Floral design kits

Plus —

  • Meet the author of Success with Hydrangeas: A Gardener’s Guide Book(B&B Publications, 2017), Connecticut horticulturist, garden writer, speaker and Advance Master Gardener Lorraine Ballato.
  • Bid on our Silent Auction gardening and specialty items.

And much more!

The UConn Extension Master Gardener Program is an Educational Outreach Program that is part of UConn Extension, College of Agriculture, Health and Natural Master Gardener logoResources, University of Connecticut. Started in 1978, the program consists of horticulture training and an outreach component that focus on the community at large. Master Gardeners are enthusiastic, willing to learn and share their knowledge and training with others. What sets them apart from other home gardeners is their special horticultural training. In exchange for this training, Master Gardeners commit time as volunteers working through their local UConn Extension Center and the Bartlett Arboretum in Stamford to provide horticultural-related information to the community. The staff and volunteers of the UConn Extension Master Gardener Program and the UConn Home & Garden Education Center are informational resources for the residents of Connecticut and beyond, who are urged to contact us for accurate, thorough, and timely information on home and garden topics.

The cooperative extension system connected to land-grant universities was established in 1914. Before the 1970s, extension horticulture programs focused on crop production. In the early 1970s Washington State University Extension agents, responding to increased public demand for gardening information through an urban horticulture program, proposed recruiting and training volunteers to respond to gardeners’ questions as a way to serve the needs of home and community gardeners. Although initially met with skepticism, the first Master Gardener training classes were offered to about 200 people in 1973. Today, Master Gardener programs are active in all 50 states, nine Canadian provinces, and in South Korea. According to a 2009 survey, 94,865 Extension Master Gardener volunteers throughout the United States contributed 5,197,573 hours educating the public, providing youth programs, and facilitating produce donations to food banks, an estimated contribution of $101.4 million to the public.

Horticultural Opportunities

 

working in garden
Hartford County Master Gardener Coordinator Sarah Bailey and a Master Gardener volunteer work in Burgdorf. Photo: Chris Defrancesco.

The UConn Extension Master Gardener program is a program that offers many different opportunities through the horticulture world. There are many qualities that are vital to becoming a Master Gardener, such as being eager to educate your community, participating in training programs, and wanting to learn more about plant care and gardening. It is never too late to become a Master Gardener. Applications are available now at MasterGardener.UConn.edu and due October 9th.

Once you have enrolled to be a Master Gardener, you will start working on your certification to become an official Master Gardener. Some things that you need to do to achieve this certification is completing a 16-week course that meets once a week, and complete a 60 hour internship that includes working in one of 9 UConn Extension offices statewide for hands on training, and working on a community outreach program. Rebecca Foss, one of the class of 2015 Master Gardeners talks about her experience in the Master Gardner’s office in the Tolland County Extension office, and how she was always eager to help out with anyone that had questions about plants.

“One of the most rewarding experiences was in the Tolland Master Gardner office. I had approached my office hours with an open mind but some underlying (but mild) trepidation as I wondered whether or not I would be able to actually make a correct diagnosis.” Rebecca later found a piece of pine that had some sort of disease on it and the owner of the pine wanted to figure it out so he could try and treat it. Rebecca and her co-worker went underway to try and figure out what they were dealing with. “We quickly ruled out some causes (we hadn’t had a drought last year) and focused on others. Soon, diplodia tip blight (Sphaeropsis sapinea), which my partner found in a book, began to look like the potential culprit.” Rebecca states. Once Rebecca and her partner got the specimen under the microscope, “I looked under the papery leaf sheaths as recommended and… Bingo! There they were!”

The Master Gardener Program is full of many different opportunities for you to learn new things about plants, but to also fulfill a lifelong hobby you may never have thought pursuing. Learn more at MasterGardener.UConn.edu

Article by Katy Davis

Building Community Through a Garden

Dozens of bright yellow Goldfinches flew alongside as I made my way up the winding driveway past their meadows and into the heart of the 4-H Education Center at Auerfarm in Bloomfield. The high, wiry whistle of the birds sounded the alarm at my arrival. I parked behind the barn, and climbed the hill to the Foodshare Garden, a project of the UConn Extension Master Gardener program.

The UConn Extension Master Gardener Program has provided horticulture training and a community outreach component for the last 40 years. Master Gardeners are enthusiastic and willing to learn. They share their knowledge and training with others through community outreach projects.

The 120-acre 4-H Education Center at Auerfarm is a private, non-profit education center. It was deeded to the Connecticut 4-H Development Fund by the family of Beatrice Fox Auerbach in 1976. Over 15,000 students and family members participate annually in year-round 4-H curriculum-based school science programs, animal clubs, and Junior Master Gardening projects.

One of the Master Gardener volunteers is Marlene Mayes of West Hartford. She grew up on Tariffville Road in Bloomfield. The 1774 house was the only one left standing after King Philip’s War and later, was part of the Underground Railroad. The oldest of six children, Marlene spent her youth playing in the woods and building hay forts with her sister in the neighbor’s barn. Life often has a way of coming full circle, Marlene is back gardening in the same area of Bloomfield as the lead volunteer in the Foodshare Garden.

The Beginning

Marlene and student at Auerfarm
Marlene (far right) with a group of students at Auerfarm. Photo: Sarah Bailey

Marlene retired in 2001 from the Torrington Public School System, but wasn’t ready for full retirement, and became the School Administrator at Grace Webb School in Hartford. She also wanted to take the Master Gardener course, and the director at Grace Webb allowed her to use her vacation time for the Wednesday class each week from January through April of 2004.

“I was lucky to merge the ending of one phase with the beginning of another, and hook into something I was so interested in,” she says. The 4-H Education Center at Auerfarm was one of the group outreach assignments for Master Gardener interns.

“When we went up to the 4-H Education Center at Auerfarm in the beginning it was just a field, an overwhelming field. We started by weed whacking rows between the grass,” Marlene recalls. “There was no coordination, it was very frustrating. I decided to take over, and got my husband Ed involved and a couple of other guys. They weed whacked, mowed and rototilled for us.”

“Our goal is to raise sustainable, low-maintenance plants that people can replicate at home,” Marlene says. “We planted currants, elderberries and asparagus. The whole garden is about teaching and getting people to grow things in their own backyard.”

In 2006 Marlene and her group of volunteers at the 4-H Education Center at Auerfarm asked the Hartford County Extension Council for money to build raised beds, and began installing them. There are 50 raised beds in the garden now. The following year, she found herself serving on the Extension Council too.

“Sarah Bailey became the Master Gardener Coordinator for Hartford County the year after I began volunteering. She’s been supportive from day one, and we’ve also become very good friends. Sarah is a big part of creating that community around the program. She talks with us about problems and helps us find creative solutions. She has wonderful leadership skills. We also developed the Junior Master Gardener Program and conducted a teacher training for some school gardens, and developed curriculum for them to use.”

The Volunteers

The volunteer community in the Foodshare garden at 4-H Education Center at Auerfarm has a lot of fluidity; people come and stay for as long as they can. Marlene tries to plant something interesting every year to engage the volunteers. Many of the volunteers are consistent and have been with the program for six or eight years; for example, one gentleman is totally focused on the maintenance and has been coming for years to help with it. Over the course of a summer there will be 600 volunteers total working in the garden. High school students volunteer in May and June fulfilling the hours required by their school. These students often keep volunteering after their hours are done.

“There is a sense of community and excitement to whatever it is we’re doing at the garden; every day is a new day,” Marlene says. “We had a woman come with her son this summer, and she stayed while her son was volunteering. They were planting a new succession of beans, and she said, ‘This is fun!’ – it’s really neat to get that reaction from adults. You’re up there almost next to the sky when you’re working in this garden.”

The volunteer schedule hasn’t changed since Marlene took over in 2004. Volunteer days are Thursday and Saturday from 9-12, unless it’s raining. In the hot weather the volunteers take more breaks and use the benches. The benches also enhance the meditative function of the garden.

Thursday is harvest day and Saturdays are for maintenance. Marlene’s husband, Ed, loads up the car on Thursday and takes the produce to Foodshare. “Ed has been a consistent back-up for me all of these years, I couldn’t have done it without him,” Marlene says. “Our son Tim has also helped with maintenance.”

“We’ve met people from all over the world in the garden,” Marlene continues. “It’s absolutely amazing. African exchange students in the agricultural business program at UConn come up every summer. We learn a lot by comparing notes. We also had a fellow Master Gardener from an Israeli kibbutz who was very interesting to talk with.”

In 2017, the garden produced 4,423 pounds total that was donated to Foodshare. This year, the volunteers are measuring donations by the number of meals, although Marlene notes that the total may be lower because of weather related challenges.

The Gardens

The Foodshare garden is ¼ acre. Two years ago Marlene fundraised for a fence for the garden because the deer were eating everything. Now the challenge is the

raised bed in foodshare garden
A raised bed in the Foodshare Garden. Photo: Stacey Stearns

woodchucks and the rabbits.

The Medicinal Garden, Greenhouse and Herb Garden were all funded by UConn Extension. Marlene designed the circular herb garden. Funding for projects that the Master Gardeners complete at the 4-H Education Center at Auerfarm is from UConn Extension, the Connecticut Master Gardener Association, or fundraised from private donors. Even the seeds used to grow the garden are obtained through donations.

Projects are implemented in phases. The greenhouse was built with funds from a grant by an anonymous donor to the UConn Foundation who greatly appreciated what the Master Gardeners are doing through their community outreach. The first-year volunteers had to haul water up the hill in buckets from the kitchen. This year, irrigation was installed for the greenhouse, solving the water problem.

“You keep learning as you go – mechanics, botany, pest management and whatever else is needed. We all work together as a team,” Marlene says. “It’s not a one-person thing. We’re all passionate about gardening, creativity, and work together to make it happen.”

“It never stops at the 4-H Education Center at Auerfarm; something is going on all of the time. If you tie into any part, it’s fascinating. Everything is research-based, the greenhouse is always a research project. We also have to factor in daylight hours, watering schedules, and how many growing seasons we can fit in each year. There is enthusiasm for wherever the problem we have to solve is.”

The next challenge for this intrepid group of volunteers is figuring out how to run the greenhouse in the colder winter months. The cost of propane has been a challenge; however, the group wants to donate consistently to Foodshare throughout the year. They are discussing raising house plants or some sort of tropical that can be sold as a fundraiser, and used as a teaching tool for the students that visit the farm each year. Tomatoes and peppers will be transplanted from the garden into the greenhouse this fall, and microgreens will also be raised for Foodshare.

Marlene also wants to continue expanding the medicinal garden and the educational component around it. Native American medicinals fascinate her as she discusses how it’s never a single herb, and always a combination of herbs.

“Our volunteer work at the 4-H Education Center at Auerfarm is never boring, and I’m not tired of it yet,” Marlene concludes. “The Master Gardener program creates a sense of community and camaraderie. There is no judgement, everyone works together and has a sense of responsibility – it’s very binding in a nice way.”

Applications are currently available for the 2019 UConn Extension Master Gardener program. Classes will be offered in Stamford on Mondays, Haddam on Tuesdays, Farmington on Wednesdays (an evening class), Bethel on Thursdays, and Brooklyn on Fridays. Applications are due by Tuesday, October 9th. More information can be found at mastergardener.uconn.edu.

To learn more about volunteering in the Foodshare Garden at the 4-H Education Center at Auerfarm for the 2019 growing season email Sarah.Bailey@uconn.edu or call 860-409-9053. To make a donation please visit http://s.uconn.edu/givemg.

Article by Stacey Stearns

Apply to Become a UConn Extension Master Gardener

collage of Master Gardener photosDo you love gardening? Are you interested in expanding your knowledge and sharing that knowledge with others? Applications are now available for the 2019 Master Gardener Program through UConn Extension. Participants receive horticultural training from UConn, and then share that knowledge with the public through community volunteering and educational outreach efforts. Enrollment in the UConn Extension Master Gardener program is limited and competitive.

The program is taught in a hybrid class format. There are 3-4 hours of online work before each of the weekly classes, and then a half-day classroom session. Most classes run from 9 AM to 1 PM. New this year is an evening session, from 5:30 – 9:30 PM, which will be held in Farmington on Wednesdays.

“Gardening and the study of it is something we can do our whole lives,” says Karen Linder, a 2015 graduate of the UConn Extension Master Gardener Program at the FANs gardenBartlett Arboretum in Stamford. “There is always something new to learn – we can get deeper into a subject. Our instructors truly brought subjects to life that I thought could not be made exciting. Who knew soil had so much going on? It has truly changed the way I think and observe the world around me. That is pretty amazing!”

The program is broad-based, intensive, and consists of 16 class sessions (online course work and a half-day class each week) beginning the week of January 7, 2019. The Master Gardener program includes over 100 hours of training and 60 hours of volunteer service. Individuals successfully completing the program will receive UConn Extension Master Gardener certification. The program fee is $450.00, and includes all needed course materials. Partial scholarships may be available, based on demonstrated financial need.

“I would recommend the UConn Master Gardener program to anyone with a serious desire to learn more about horticulture,” says Holly Maynard, a 2017 graduate of the Hartford County class. “There are some spectacularly engaging guest lecturers; this is not some amateur gardening club.”

Classes will be held in Farmington, Bethel, Haddam, Brooklyn and Stamford. The deadline for applications is Tuesday, October 9, 2018.

For more information, call UConn Extension at 860-409-9053 or visit the UConn Extension Master Gardener website at: www.mastergardener.uconn.edu, where both the on-line and paper application can be found.

Can I Water Vegetables with my Rain Barrel Water?

By Joan Allen

Originally published by the UConn Home & Garden Education Center

rain barrel against side of house in with shrubs
Photo credit: CT DEEP

Collection of rain water from roofs using rain barrels is growing in popularity because of its many environmental and practical benefits. It can help the environment by diverting water that might contain contaminants away from storm drains and the natural bodies of water that those empty into.  Depletion of well water can be a benefit when this non-potable water is used instead of the tap for things like washing cars, irrigation of plants, and flushing toilets. If you’re on a city/public water system, it can save money to use rain water where you can, too. But is using rain water to irrigate vegetables and fruits safe? Are there contaminants in it that could make people sick? Let’s take a look at what’s been studied.

A few universities in the U.S and abroad have done some work to look at potential contaminants in roof run-off water including heavy metals like zinc, copper, lead and others as well as bacteria such as E. coli and other pathogens. Testing done so far has shown low risk from these, but there is some. And of course, it depends on the type of roofing material, the environment (ie acid rain, urban vs. rural, etc) and possibly other factors. In one study, most of the metals tested the same in rain barrel water as in rain water before it hit the roofs, so little to no concern there. One exception was zinc, and elevated levels could lead to build up of this element in soils. At high enough levels, this can cause injury to plants and those plants should not be consumed (1). Monitor for this by having the soil tested.

While risk appears to be low, there were a few samples in studies (1, 2) where E. coli or total coliform bacterial levels exceeded official standards for some uses. Rain barrel water should NEVER be used for potable purposes such as drinking water, cooking or washing. Where do the bacteria in run-off come from? The main sources would be fecal matter from animals such as squirrels and birds that land and move around on the roof.

But if you’d like to water your vegetable garden with rain barrel water, are there ways to do it safely?

Dr. Mike Dietz, Assistant Extension Educator at UConn with expertise in water management recommends “not using roof water on anything leafy that you are going to eat directly. It would be OK to water soil/plants where there is no direct contact”. This is consistent with recommendations from other experts who suggest applying the water directly to the soil and avoiding contact with above-ground plant parts. An ideal set-up would be to hook up a drip irrigation system to your rain barrel(s). Pressure will be improved when they are full and if they are elevated. A full rain barrel can be pretty heavy, at about 500 lbs. for a 55 gallon unit, so make sure they are on a solid and stable base such as concrete blocks.

If possible, and this is done in larger collection systems automatically, don’t collect the ‘first flush’ of water off the roof. This would be the first few gallons. In a ¼” rainfall as much as 150 gallons can be collected from a 1000 ft2 roof surface (3). The first water to run off tends to have higher concentrations of any contaminants because of them building up on the roof since the previous rainfall event.

Another more practical way to minimize risk of pathogen/bacterial contamination is to treat the collected water with bleach. Rutgers University recommends treating 55 gallons of water by adding one ounce of unscented household chlorine bleach to the barrel once a month (or more often if rain is frequent). Allow this to stand for 24 hours before using the water for irrigation so the bleach can dissipate.

Apply collected water in the morning. Wait until leaves dry in the sun before harvesting. Ultraviolet light from the sun will have some disinfecting effect.

It is recommended to have the rain barrel water tested for E. coli. Be sure to follow the testing lab’s instructions for collection, storage and time sensitivity of the samples.

Thoroughly wash all harvested produce. In addition, you should always thoroughly wash your hands with warm, soapy water after they are in contact with collected water.

In summary, there are risks to using collected rain water for irrigation of food crops. In most cases, the risk appears to be low, and using the above sanitation practices can reduce risk.

References:

  1. DeBusk, K., W. Hunt, D. Osmond and G. Cope. 2009. Water quality of rooftop runoff: implications for residential water harvesting systems. North Carolina State University Cooperative Extension.
  2. Bakacs, M., M. Haberland and S. Yergeau. 2017. Rain barrels part IV: testing and applying harvested water to irrigate a vegetable garden. Rutgers New Jersey Agricultural Experiment Station. Fact Sheet FS1218.
  3. Rainfall as a resource. A resident’s guide to rain barrels in Connecticut. CT DEEP.