Welcome to Doctor Green Thumb, LLC
Serving discerning plant, soil, lawn, and tree enthusiasts online, central Utah, and worldwide since 2013, Doctor Green Thumb LLC has been your trusted source for all your landscaping needs.*
Services Provided
WHAT THRIVES in YOUR SOIL
Lawn, flowers, vegetables, and ornamental gardens all differ in their nutrient and watering needs. Soil texture and pH govern nutrient availability, water flow, and root oxygen, which is essential for understanding how to water wisely. By consulting with Doctor Green Thumb you can save money and frustration by learning about your soil.
PEST CONTROL
Doctor Green Thumb,LLC offers weed, insect, and disease control treatments available on a regular interval or one-application basis.
LAWN REJUVENATION
Restore your unhealthy lawn rather than replace it with the help of Doctor Green Thumb, LLC. Save money, water, and time while ultimately improving your soil, lawn health, and appearance.
BEAUTY by DESIGN
Blend your style with our helpful design expertise at Doctor Green Thumb LLC. We'll assist you in planting or guide you to do it yourself.
IDENTIFY the PROBLEM
IDENTIFY the PROBLEM
IDENTIFY the PROBLEM
Lawn, flowers, vegetables, and ornamental gardens all differ in their nutrient and watering needs. Soil texture and pH govern nutrient availability, water flow, and root oxygen, which is essential for understanding how to water wisely. By consulting with Doctor Green Thumb you can save money and frustration by learning about your soil.
PRUNING & MAINTENANCE
IDENTIFY the PROBLEM
IDENTIFY the PROBLEM
Doctor Green Thumb,LLC offers weed, insect, and disease control treatments available on a regular interval or one-application basis.
RESOLVE the PROBLEM
IDENTIFY the PROBLEM
RESOLVE the PROBLEM
Restore your unhealthy lawn rather than replace it with the help of Doctor Green Thumb, LLC. Save money, water, and time while ultimately improving your soil, lawn health, and appearance.
Who Is Doctor Green Thumb?
Our Vision
At Doctor Green Thumb, LLC, we strive to be a leading diagnostic, landscape, and environmental consulting firm that inspires and empowers individuals and organizations to take action towards a more sustainable future. We believe in the principles of Integrated Pest Management, using or recommending an organic or synthetic pesticide when warranted. We welcome your input and will discuss options with you should you bring it to our attention.We are here to give you the best option(s) for the situation.
Our Leader
At Doctor Green Thumb, LLC, the leader of Doctor Green Thumb, LLC is Dr. Teri Gadd, Ph.D. Although she has spent the majority of her life working with seeds, plants, trees, insects, soils, weeds, turfgrass, and more, it wasn't until after she had designed and installed over an acre containing an orchard, a vegetable garden, a small berries garden, 1,000s of spring and summer bulbs, perennials, custom seeded lawns, with dozens of evergreens and deciduous trees and shrubs everywhere you turned that she realized she would pursue graduate degrees in plant sciences. Her education enhanced her existing experience which created the dynamic, knowledgeable, highly rated educator, scientist, and entrepreneur that we know today.
To learn even more, we've posted her CV. Enjoy!
Our Leader
CV
Teri Gadd
(970) 218-2599 teri@docgreenthumb.com Monroe, UT & formerly Ft. Collins, CO
·
Education
- Ph.D. Horticulture
· Concentrations in Tree Water Stress Physiology, Chemical Ecology, and Insect Behavior
· Dissertation: “Post Thinning Interactions between Lodgepole Pine Host Physiology, Growth, Chemistry, and Survival with Mountain Pine Beetle”
College of Agriculture, Colorado State University, (CSU), Fort Collins CO
- M.S. Horticulture
· Concentrations in Weeds, Herbicide Physiology, and Horticulture
· Thesis: “Efficacy and Phytotoxicity of Preemergence Herbicides in Container-Grown Landscape Plants” College of Agriculture, CSU, Fort Collins CO
- B.S. Biology with Minor in Chemistry
Southern Utah University, Cedar City UT
Professional Experience
- Soil, Abiotic, Tree, Plant, Insect, Disease, & Weed Consultant/Owner 4/15/2011-present
Doctor Green Thumb, LLC, Fort Collins, CO & Monroe, UT Website: DocGreenThumb.com
· Identify &/or survey land, vegetation & soils to diagnose plant, disease, insect, weed, invasives disturbances, give management recommendations for land use, tree & plant health, soil, water-use efficiency, tree & shrub pruning, or abiotic plant problems, as well as interpret lab results, structurally prune trees & shrubs, design and remodel landscapes for commercial and residential clients.
Hours worked per week: 10-40
Teri Gadd (owner), Doctor Green Thumb, LLC, Fort Collins, CO and Monroe, UT, 970-218-2599
- Forest Botanist and Pollinator Coordinator 11/5/2023-9/27/24
Fishlake National Forest, USDA-Forest Service, Supervisor’s Office, Richfield, UT
· Identified Endangered, Threatened, Candidate, Sensitive, and Proposed plant and insect species as listed by U.S. Fish and Wildlife Service during ground surveys.
· Tracked species via GIS, GPS, and tablet software, provide information to projects.
· Wrote NEPA checklists and reports, request for concurrence letters, biological analyses and biological evaluations for each project.
· Monitored upland pasture study sites within allotments doing tri-transects at foot increments for over 100’ from each stake transect and monitored upland pasture pollinators using Xerces Society pollinator protocol and pollinator instruction sheet I created as Pollinator Coordinator.
· Attended botany and pollinator meetings, trainings, and project IDT meetings providing preliminary indications of listed plants found in project areas.
Hours worked per week: 40+ GS Level 7.
Ecosystem Staff Officer, Fishlake National Forest, USDA-FS, Richfield, UT, 435-896-9233
- Primary Researcher, Lodgepole Pine Physiology-Ecology-Insect Interactions 1/1/2008 – 12/15/2021
Dept of Horticulture and Landscape Architecture, CSU, Fort Collins, CO
· Led two research studies addressing plot density, inventory, classification, precipitation, tree age, in Mountain Pine Beetle (MPB) disturbances to determine physiologic and environmental influences and dynamic volatile chemistry of Lodgepole pines on colonization success of MPB.
· Inventoried & classified 4 lodgepole pine plots, used GIS and headspace SPME and GC-MS to analyze 492+ forest foliage samples taken over two growing seasons to determine changes over MPB flight season of 72 Lodgepole mono- and sesquiterpenes.
· Tested Lodgepole pine foliage samples using pressure chamber (Ψ) and season end δ13C isotopes.
· Collected increment cores, DBH, tree height, Lindgren funnel trap beetle counts, and documented MPB beetle hit status per studied tree.
· Analyzed 30 container Lodgepole seedlings subjected to water stress gradient demonstrating decreased terpene volatile profile with increasing water stress.
· Analyzed soil volumetric water content utilizing theta probe and terpene profiles (HS-SPME).
· Substantiated drought influence using water potentials (Ψ), δ13C isotopes and theta probe.
· Showed best plot density & tree age for tree health to minimize vegetation disturbance & fire.
· Illustrated tree volatile profile change throughout season, at beetle flight, age, and density.
· Determined key host chemical compound deterrents in Mountain Pine Beetle (MPB) disturbance using HS-SPME and GC-MS.
Hours worked per week: 10-50
Dr. Seth Davis, Dept. Forest & Rangeland Stewardship, CSU, 970-491-6980
Jose Negron, Rocky Mountain Research Station, USDA-FS, 970-286-4568
Dr. Lou Bjostad (mentor), Dept. of Bioagricultural Sciences & Pest Management, CSU, 970-491-5987
- Adjunct Professor HLT240 (Soil Science) & HLT242 (Turfgrass Management) 4/15/2014–8/30/2020
Dept. of Applied Env. Sci., Horticulture & Landscape Tech., Front Range Community College, Fort Collins, CO
· Educated students through lecture, labs, & applied experiences in soil & turfgrass subjects including soil physics, chemistry, water, microbiology, soil texture, & management as well as turf, germination, pests, diseases, cold & warm turf species, weeds, & management.
· Engaged students’ critical thinking skills with semester applied project using lab & lecture principles.
Hours per week during semester: up to 24
Molly McDonald (lead instructor), Dept. of Applied Env Sciences, HLT, FRCC, 970-204-8306
- Academic & Study Skills Workshop Facilitator 8/20/2012-5/10/2015
The Institute for Learning and Teaching at CSU, Fort Collins, CO
· Taught engaging academic workshops to CSU students on time management, test taking, reading, memory & concentration, note taking, motivation, goal setting, procrastination, and active learning.
Hours worked per week: 1-4
Darrie Burrage, Director of Learning Programs, TILT, CSU, 970-491-2519
- Instructor-GTA, Graduate and Faculty Seminar (Hort 672) 8/20/2007-5/10/2010
Department of Horticulture and Landscape Architecture, CSU, Fort Collins CO
· Developed curriculum and topics schedule as well as invited and hosted speakers from federal, state, academic, and local experts.
· Mentored 30+ graduate students per year including proposal and exit seminars, department and university requirements, arranged skill workshops, and edited graduate student manual.
Hours worked per week: 10
Dr. Steve Wallner (dept. head), Dept. of Horticulture and Landscape Architecture, CSU, 970-491-7018
- Instructor, GTA, General Horticulture Lab 8/20/2006-12/10/2010
Department of Horticulture and Landscape Architecture, CSU, Fort Collins CO
· Instructed 25-50+ non-major and major students per semester, wrote quizzes, planned lessons, set up lab, assigned reading and homework, and graded student work.
· Updated and revised lab manual from 20-year-old version.
· Educated students in basic horticulture topics including woody and herbaceous vegetative structures, fruit structures, scientific method and reporting, asexual and sexual propagation, plant pests/diseases, pruning, turf, plant identification, and plant care.
Hours worked per week: 10
Dr. Harrison Hughes, Dept. of Horticulture and Landscape Architecture, CSU, 970-491-7050
- Advanced Environmental Plant Stress Physiology GTA, (Hort 576) 1/19/2006-5/10/2006
Department of Horticulture and Landscape Architecture, CSU, Fort Collins CO
· Coordinated rotation of scientific paper discussion groups. Prepared pdf documents for course reading.
· Developed & presented lectures on “bio-chemical cross-talk” and “plant-insect interaction stress.”
Hours worked per week: 10
Dr. Bill Bauerle, Dept. of Horticulture and Landscape Architecture, CSU, 970-491-4088
- Graduate Researcher for USDA IR-4 Small Crops Herbicide Testing 5/20/2005–8/20/2007
Department of Horticulture and Landscape Architecture, CSU, Fort Collins CO
· Investigated tolerance and phytotoxicity of ornamental crops with pre-emergent herbicide concentration gradients.
· Produced statistical analysis, IR-4 report, and two journal articles.
· Study results from testing of six pre-emergent herbicides were combined with other IR-4 test centers to provide herbicide labeling for use on seven popular perennials and one woody crop.
Hours worked per week: 10-40
Dr. Jim Klett, Dept. of Horticulture and Landscape Architecture, CSU, 970-491-7179
- Therapist Scheduler and Office Manager 8/1/1995-12/15/1998
Northern Colorado Therapists, Inc., Fort Collins, CO
· Assigned over 70 physical, occupational, and speech therapists daily from on-call therapist registry to regional hospitals and orthopedic facilities.
· Was directly responsible for directing office affairs, OSHA employee data, compliance, & schedules, and client communications.
· Over 400% growth in business.
Hours worked per week: 40
Jennifer Heath, Owner of Northern Colorado Therapists, Inc., Fort Collins, CO, 970-224-9113
- Quality Assurance Manager 9/1/1993-1/10/1995
Colorado Histo-Prep, Inc., Fort Collins, CO
· Conducted audits for GLP studies as laboratory’s objective quality assurance unit.
· Generated SOPs, kept lab in compliance with FDA and EPA (FIFRA & TSCA) guidelines.
· Directed facets of the laboratory including interviews, billing & payroll, marketed at national convention, and corresponded with clients.
· Insured quality for over 100 studies. Passed FDA unannounced inspection.
Hours worked per week: 40
Janet Maass, Owner of Colorado Histo-Prep, Inc., Fort Collins, CO, 970-490-2660
Research Skills and Qualifications
· Technical & Field Skills: SAS statistical software, JMP, experiment design, sampling techniques, regression analysis, Theta probe, increment corer, DBH, lawn water audits, water stress-pressure chamber, sprinkler timing audits, and more.
· Laboratory Skills: GC, GC-MS, HS-SPME, thin layer chromatography, liquid chromatography, δ13C
isotope analysis, increment core ring analysis, insect rearing, and insect bioassay.
· General Skills: Leadership, social media, grant writing, analytical, online or in-person presentations, Microsoft Excel, Word, Powerpoint, & Publisher, Quicken, plus much, much more.
Professional memberships
Soil Science Society of America 2020-present
Western Forest Insect Work Conference 2008-present
National Association of Agricultural Educators 2008-present
Weed Science Society of America 2017-present
American Society for Horticulture Science 2007-present
Leadership Experience
Chair, Chair-Elect, Secretary 2010, 2011, 2012, & 2013
American Society for Horticultural Science Weed Control & Pest Management Working Group
Chair, Chair-Elect, Secretary 2007, 2008, 2009, & 2010
American Society for Horticultural Science Environmental Stress Physiology Working Group
Advisory Board Member 2008-2016
The Institute for Learning and Teaching, Colorado State University
Horticulture Graduate Representative 2006-2010
Technology Fee Committee, College of Agricultural Sciences, Colorado State University
College Recruiter November 2009
Agriculture Future of America Conference Opportunity Fair, College of Agricultural Sciences, CSU
Coordinator for STEMapalooza October 2009
CSU’s College of Agricultural Sciences, Colorado Convention Center, Denver CO
Awards, Honors, Grants, and Fellowships
- Pi Alpha Xi 2008-2021 graduation National Horticulture Honor Society, American Society for Horticultural Science, GPA of 3.975
- Charles N. Shepardson Graduate Student Teaching Award May 2008 College of Agricultural Sciences, CSU
- Colorado Garden Show, Inc. Graduate Scholarship (2008-2009 tuition/fees/books) April 2008
- American Society for Horticultural Science Industry Division Student Travel Grant: $750 July 2009 (Annual conference in Florida-sole recipient from national pool)
- American Society for Horticultural Science Annual Conference Student Travel Grant: $500 2008
- Tree Physiology-Insect Interactions Research Fund, self-funded: $7,100 2008, 2012, & 2013
- Tree Physiology-Insect Interactions Research Fund, Intel Corp. Company Match, $4,000 2008
Presentations
- Gadd, T. “Sustainable Weed Management” Workshop Coordinator & Moderator, American Society for Horticultural Science Annual Conference, Desert Springs, CA (July 2013)
- Howlett, T. (2010). “Utility of Mechanistic and Empirical Models for Basic and Applied Research in Horticultural Stress Physiology: What You Need to Know Even If You’re Not a Modeler” Workshop Coordinator & Moderator, American Society for Horticultural Science Annual Conference, Desert Springs, CA. HortScience 45(8):S46.
- Bauerle, B, Lea-Cox, JD, Ristvey, A, van Iersel, M, Mattson, N, Howlett, T. (2010) Panel Discussion: Modeling Uses, Pros and Cons. American Society for Horticultural Science Annual Conference, Desert Springs, CA. HortScience 45(8):S47.
- “Improvement of Horticultural Crops for Abiotic Stress Tolerance” Colloquium Co-Sponsor: Environmental Stress Physiology Working Group, American Society for Horticultural Science Annual Conference, Desert Springs, CA, (2010).
- Howlett, T. Staats, D. Klett, J (2007) American Society for Horticultural Science Oral Session 15: Ornamentals/Landscape & Turf 1 “Efficacy and Phytotoxicity of Preemergence Herbicides in Container-grown Landscape Plants.”
- Howlett, Teri (2007). ProGreen. CSU Research Updates. “Efficacy and Phytotoxicity of Preemergence Herbicides in Container-grown Ornamentals and Woody Plants.”
- Howlett, Teri (2006) Colorado State University Field Day, Herbicide ornamental research update.
Publications
- Gadd, T., Bauerle, W., Aguayo, I., Bjostad, L. (July 2013). Bark Beetle Flight in Relation to Lodgepole Pine Host Chemistry: Another Case for Coevolution? HortScience 48.
- Howlett, T. Bauerle, B. Bernklau, E. Bjostad, L. (2010). Seasonal Chemical Variation in Lodgepole Pine Physiology: A Predictor of Mountain Pine Beetle Colonization Success? HortScience 45(8):272.
- Howlett, T. Aguayo, I. Bauerle, B. Negron, J. Bjostad, L. (2009). Tree Physiology-Bark Beetle Interactions: Effects of Thinning and Environmental Stress-Early findings of ongoing research. 60th Annual Western Forest Insect Work Conference Proceedings.
- Bauerle, W., R. Reynolds, et al. (2008). “Predicting the growth of deciduous tree species in response to water stress: FVS-BGC model parameterization, application, and evaluation.” HortScience 43 (4): 1276-1276.
- Howlett T, Aguayo, I. Bauerle, B. Negron, J. (2008). “Physiologic effects of thinning/soil moisture ratio on tree vigor and resistance to bark beetle pressure – Proposed research.” 59th Annual Western Forest Insect Work Conference Proceedings, 70-71.
- Klett JE, Staats, D. Howlett, T. Rogoyski, M. 2008. Weed Control and Phytotoxicity Following Preemergence Herbicide Applications to Container-grown Herbaceous Plants. Journal of Environmental Horticulture 26(1):39-44.
- Howlett T, Staats, D., Klett, J. (2007). Efficacy and Phytotoxicity of Preemergence Herbicides in Container-grown Landscape Plants. HortScience 42: 877.
- Staats D, Klett, J, Howlett, T, Rogoyski, M. (2006). Preemergence Weed Control in Container-grown Herbaceous Perennials. HortScience 41: 1034.
PROPOSED Publications
- Gadd T, Davis S, Aguayo I, 2025. “δ 13C Isotopes and water potentials (Ψ) of Lodgepole pine across density gradient: Is drought to blame for bark beetle success?” Submitting to Forest Ecology and Management
- Gadd T, Davis S, Aguayo I, Bernklau E, 2025. “Environmental and Physiological Effects on Terpene Chemistry of Lodgepole Pine and its Relationship to Mountain Pine Beetle Colonization.” Submitting to Chemical Ecology
- Gadd, TA, Staats D, Klett, JE. 2025 “Efficacy and Phytotoxicity of Preemergence Herbicides in Container-grown Ornamentals.” Submitting to Journal of Environmental Horticulture.