Earth-Kind® Shrub Trials in the Upper Midwest
Background
In the U.S., three of the largest environmental concerns regarding American landscapes are: (1) the
depletion of limited water resources through irrigation practices, (2) inappropriate fertilizer and
pesticide use and their impacts on environmental quality and ecosystem health and (3) the large
amounts of yard waste deposited in landfills. At the individual level, gardeners struggle with (1)
growing plants in poor quality soils created by disturbance during urban construction and (2)
maintaining plants that are poorly adapted to the pests and growing conditions in their region of the
U.S. In particular, we are all experiencing changes in rainfall patterns: heavier, larger rainfalls with
longer and more frequent periods of drought in between.
In the early 1990’s, Dr. Steve George at Texas AgriLife Extension Service at Texas A&M University
initiated the Earth-Kind® program, which addresses all of these concerns by providing researchbased information on environmentally responsible cultural practices and wise plant selection in the
ornamental landscape.
As individual gardeners, our impact on the environment may be minimal but collectively we have a
large and sometimes negative impact. If we as individuals change our practices, we can collectively
reduce or eliminate our negative impact. That is what Earth-Kind is about: changing our practices
to create effectiveness and efficiency in the creation and maintenance of beautiful, productive
landscapes and gardens. Earth-Kind changes “aesthetics vs. sustainability” to “aesthetics and
sustainability”.
Key components of program are:
1. identifying and teaching landscape practices focused on:
 nutrient management without inorganic fertilizer applications
 improving overall soil health with compost & organic mulch
 water conservation (selecting drought-tolerant plants, use of drip irrigation)
 minimizing pesticide use
2. identifying plant cultivars & species that perform well over multiple years & over a regional basis
when:
 inorganic fertilizer and pesticide use are eliminated
 compost and organic mulch are used as nutrient sources
 supplemental irrigation is minimized
How Earth-Kind Works
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Pick cultivars to be trialed and multiple evaluation sites across a region
Pick a cultivar currently in the trade and known for its good performance to use as a standard to
compare trial plants to.
Prepare 4 beds or “blocks” by killing existing vegetation.
Add 3” of compost and incorporate it in to a 6-8” depth.
Plant each cultivar in each of the 4 blocks in a randomized design.
Apply 3” of wood chips or other organic mulch to the bed. This 3” is maintained throughout the 4
year study by reapplying mulch as needed.
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Irrigate plants regularly throughout year 1 as plants establish. After year 1, plants are irrigated
only under drought conditions when plants begin to wilt.
No pesticides, fertilizer, or winter protection throughout the 4-year trial.
In years 2-4, evaluate monthly during the growing season for pest and stress tolerance and
ornamental traits
Earth-Kind designation is given to plants that perform well across all sites
Evaluation results are made available through journal articles (refereed journals, trade
magazines, gardening magazines), websites, and presentations
Earth-Kind Hydrangea Trials
24 cultivars at 5 locations:
1. Minnesota Landscape Arboretum, Chaska, MN
2. Iowa State University Research Farm, Ames Iowa
3. Cottonwood Park, Dilworth, MN
4. North Central Research and Outreach Station, Grand,
MN
5. Boerner Botanic Garden, Hales Corner, WI
Results from Texas:
Resource and labor savings:
1. 50-70% reduction in water use
2. 98% reduction of pesticides
3. 20% reduction of yard wastes from entering landfills
4. 50% labor savings in Addison, TX through reduced watering, replanting, weeding, and
pesticide applications
Designation of 23 Earth-Kind® shrub roses that thrive under low-maintenance
Gussie Field Watterworth Park,
Farmers Branch, TX
TX Myers Park, McKinney, TX
2.5 acre Earth-Kind trial of
100 shrub rose cultivars (400 plants)
http://aggie-horticulture.tamu.edu/
earthkindroses/cultivars/
E-K trials: Kordes roses, herbaceous
perennials, annuals, crape myrtle
http://collincountygardening.tamu.edu/eart
kind/earth-kind-research-gardens/