3/07/2023
Master Gardener volunteers contributed to a 5-year Extension research study 2018-2022.
The Home Garden Productivity Project sought to determine the potential of home gardens to provide significant quantities of fresh, healthful food. The project has now concluded and the results can be put to work in our communities.
A big thanks to all of the RCMG volunteers who helped collect data for this Extension Research project over the past five years: Jessi Donaldson, Beth Fritcher, Brianna Gohde, Sharon Hardy, Elisa Iha, Jean Kohs, Sarah Kruger Hilger, Sandy MacDonald, Bill Pederson, Danita Peterson, Carol Pierce, Aimee Schaefer, Chris Singer, Chris Stevens, Stasha Switzer, Kristin Thomanschefsky, and Andre Walker.
Download the Study Handout
This handout provides details and best practices for beginner gardeners. It is a 2-sided tri-fold that is great to handout at farmers markets and community gardens.
This handout, courtesy of Deon Haider (RCMG) summarizes the information from the study. It is a 2-sided that is good to help set expectations about first-time gardeners.
About this Study
The Home Garden Productivity Project sought to answer the questions; “How much food can be grown in a home garden?” and “What does it take (time and expense) to do so?” The goal was to determine the potential of home gardens to provide significant quantities of fresh, healthful food.
Karl Hakanson, previously a University of Minnesota Agriculture and Natural Resources Extension Educator for Hennepin County, partnered with University of Minnesota Extension Master Gardener volunteers with funding provided by the Hennepin County Extension Committee. Participants were asked to record information about their home vegetable gardens, including which vegetables were grown, the amount of space dedicated to each crop, the total amount of time and money spent caring for the garden, and the total amount of produce was harvested per crop. Roughly 20 Master Gardener volunteers contributed data to this study between 2018 and 2022.
Research Participants
The study involved 89 Master Gardener volunteers from Hennepin, Scott-Carver, and Ramsey counties over a 5-year period between 2018 and 2022. All participants had more than five years of experience growing vegetables at home but are not commercial growers seeking maximum production. Over half of participating gardeners have been gardening for more than 26 years. About 28% have 6-15 years of experience and 13% have 16–25 years of experience.
Garden Size
Participants used backyard gardens and community garden plots with the average size of approximately 365 square feet. (Range = 15–4,600 sq. ft.). For context, city housing lots are typically from 5,000 to 8,000 sq. ft., with suburban lots up to an acre (43,560 sq. ft.) or more.
For their garden location, few participants (6%) grew in containers, while a third (33%) grow in raised beds, and most (61%) maintain in-ground gardens. All gardens are in Hennepin, Scott-Carver, and Ramsey counties of Minnesota.
Garden Productivity/Harvest Information
The study measurements suggest that home gardeners can expect to harvest an average of
1.50 pounds of produce per square foot of garden space. This is close to 200 pounds of vegetables in the common-size home garden, which can produce almost 420 servings of vegetables, which provides the nutritional goals of a family of four for 65 days. These averages included some crop failures and less than ideal growing conditions across all years.
The study focused on annual foods, like tomatoes, cucumbers, and green beans. Perennial foods like asparagus and fruiting shrubs/trees were not included. Most participants (46%) grew a combination of hybrid and heirloom seeds and plants. More than half (55%) of participants grew vegetables to be consumed fresh while only 18% planned to preserve the majority of their produce.
Harvest Details per Vegetable
Popular vegetables (information from more than 15 gardens) are listed by the amount of food they can produce in a home garden in a single growing season below. This shows both pounds per square foot and servings. The number of servings were calculated using the total average harvest and the total average space used per crop. Serving size determined by MyPlate.gov and the USDA.
Gardeners can use this information to design a more productive home garden or to see how their current harvests compare to the average, based on participant information.
Vegetable | Pounds (per square foot) | Servings (per square foot) |
Beet | 0.72 | 3.86 |
Broccoli | 0.64 | 3.20 |
Cabbage | 1.04 | 6.76 |
Carrot | 0.80 | 5.94 |
Cauliflower | 0.50 | 2.10 |
Collard Greens | 1.21 | 15.23 |
Cucumber | 1.61 | 2.43 |
Eggplant | 0.96 | 5.32 |
Green Beans | 0.66 | 3.01 |
Kale | 0.81 | 17.47 |
Kohlrabi | 1.43 | 6.49 |
Leeks | 0.47 | 2.42 |
Lettuce | 0.57 | 7.18 |
Onion | 0.54 | 2.24 |
Parsnips | 0.72 | 2.47 |
Peas (pods) | 0.09 | 0.27 |
Peppers (Hot) | 0.54 | 2.07 |
Peppers (Sweet/Bell) | 0.57 | 2.18 |
Potatoes | 0.56 | 1.17 |
Radish | 0.41 | 1.60 |
Spinach | 0.44 | 6.62 |
Summer Squash | 2.31 | 4.69 |
Swiss Chard | 0.47 | 5.87 |
Tomatoes | 1.78 | 6.59 |
Winter Squash | 0.78 | 3.03 |
Zucchini | 1.51 | 3.49 |
Time Requirements
Participants recorded time spent on normal garden activities, including planting, watering, weeding, pest management, harvest, and end-of-season care. Gardeners with average-sized home gardens can expect working about 48 hours during the growing season, or about 2 hours every week from May through November. This is not a lot of time to spend on a rewarding activity!
Garden Costs
Gardeners spent roughly $100 per garden. Costs in the study only included materials used during the single growing season, like seeds, plants, and fertilizer; it did not include multi-season materials like raised beds, trellises, or irrigation. To compare, the value of produce from the average garden is $325, a savings of over 28% on fresh produce. This represents significant potential savings for home gardeners. While not captured in this study, all these gardeners expressed many non-monetary values associated with gardening, such as being outside, sharing with children, providing pollinator habitat, satisfaction of growing your own, flavor and quality of vine ripened fresh produce, and a needed respite from the everyday stresses of work and life.
Garden Practices
When asked about the horticultural/gardening practices used, There was no single practiced by all of the most productive growers. Most participants reported using crop rotations (81%) and fertilizers (87%). However, comparing garden to practices to garden harvest suggests that dense planting (closer than normal spacing), relay planting (reseeding a single crop multiple times), and mulching around vegetables had the greatest positive impact on yield.
Impact on Harvest (ranked) | Garden Practice | % of participants using this method |
1 | Dense Planting (square-foot gardening, close-planting techniques) | 60% |
2 | Relay Planting (reseeding a single crop multiple times) | 47% |
3 | Mulching (covering soil around plants with straw, compost, plastic) | 57% |
4 | Interplanting/Companion Planting (combining different crops into the same bed) | 55% |
5 | Vertical Gardening | 66% |
6 | Succession Planting (planting separate spring, summer, and fall crops) | 55% |
7 | Fertilizers (including synthetic, organic, compost) | 87% |
8 | Indoor Seed Starting | 60% |
9 | No-Till | 57% |
10 | Crop Rotation | 81% |
not enough info | Drip Irrigation | 19% |
not enough info | Season Extenders (cold frames, cloches, hoop house) | 32% |
not enough info | Straw Bale Gardening | 9% |
not enough info | Cover Crops | 17% |
Brianna Gohde
RCMG Volunteer