| Naturewise ColumbusBlacklick | Form 990-EZ | $68,385FY2025 |
| Twin City Parks and Waterways IncUhrichsville | Form 990-EZ | $68,350FY2025 |
| Lake Erie Waterkeeper IncToledo | Form 990-EZ | $67,619FY2024 |
| Hudson Garden ClubHudson | Form 990-EZ | $67,616FY2025 |
| Summit County Master GardenersAkron | Form 990-EZ | $66,755FY2024 |
| Little Garden Club of ColumbusBlacklick | Form 990-EZ | $64,024FY2025 |
| West Central Ohio Land ConservancyBluffton | Form 990 | $63,873FY2025 |
| International Union for the Study of Social InsectsColumbus | Form 990-EZ | $63,771FY2025 |
| Four Symbolic Lodges & Chapters FSLCCleveland | Form 990-EZ | $61,830FY2025 |
| Coah Conservation IncWest Jefferson | Form 990-EZ | $60,743FY2024 |
| Buckeye Lake for Tomorrow IncBuckeye Lake | Form 990-EZ | $60,544FY2025 |
| Ohio Stream Preservation IncOakwood Village | Form 990 | $58,969FY2025 |
| Friends of Madison County Parks and TrailsLondon | Form 990-EZ | $58,154FY2025 |
| Simon Kenton PathfindersUrbana | Form 990-EZ | $55,458FY2025 |
| Hunters Point Waterfowl FoundationAvon | Form 990-EZ | $55,128FY2025 |
| Northern Tuscarawas Land TrustZoarville | Form 990 | $50,766FY2025 |
| Syrian Cultural Garden Foundation IncChagrin Falls | Form 990-EZ | $50,620FY2025 |
| Green Energy OhioColumbus | Form 990-N | No figure |
| Cincinnati Permaculture InstituteCincinnati | Form 990-N | No figure |
| Cleveland Audubon SocietySolon | Form 990-N | No figure |
| National Scenic Byway FoundationMillersburg | Form 990-N | No figure |
| Inniswood Garden SocietyWesterville | Form 990-N | No figure |
| Friends of the Gorman Nature Center IncMansfield | Form 990-N | No figure |
| Rocky River Watershed Council IncCleveland | Form 990-N | No figure |
| Coshocton C A R E S College Access ProgramCoshocton | Form 990-N | No figure |
| Rooted in Trees Ohio LLCKirtland | Form 990-N | No figure |
| Ohio Valley Conservation CoalitionJackson | Form 990 | $35,979FY2024 |
| Friends of Scioto Brush Creek IncOtway | Form 990-N | No figure |
| Aurora Conservation Councils Moebius Nature Center IncAurora | Form 990-N | No figure |
| Friends of Big CreekCleveland | Form 990-N | No figure |
| Shared Power Network IncColumbus | Form 990-N | No figure |
| Ferncliff FoundationSpringfield | Form 990-N | No figure |
| Bishop Educational Gardens IncorporatedRockbridge | Form 990-N | No figure |
| Ohio Wetlands Association IncColumbus | Form 990-N | No figure |
| Capital City Pipes & Drums and Highland Dancers IncColumbus | Form 990-N | No figure |
| Izaak Walton League of America IncCincinnati | Form 990-N | No figure |
| Blanchard River Watershed PartnershipFindlay | Form 990-N | No figure |
| Foundation for Environmental EducationColumbus | Form 990-N | No figure |
| Just Earth - Cincinnati IncCincinnati | Form 990-N | No figure |
| Glass City Community Solar IncToledo | Form 990-N | No figure |
| Beautify BelpreBelpre | Form 990-N | No figure |
| Northwestern Ohio Rails to Trails Association IncDelta | Form 990-N | No figure |
| Ohio Native Plant MonthShaker Heights | Form 990-N | No figure |
| Irish Garden Club LLCCleveland | Form 990-N | No figure |
| Friends of Caesar Creek Cooperating AssociationWaynesville | Form 990-N | No figure |
| Ottawa River CoalitionLima | Form 990-N | No figure |
| Earth Action Partnership IncZoar | Form 990-N | No figure |
| East Green FoundationTiffin | Form 990-N | No figure |
| The Ohio Society of Radiologic Technoligists Education and ResearZanesville | Form 990-N | No figure |
| Friends of Adams County 4-H & ExtensionPeebles | Form 990-N | No figure |