Former National Champions
| |  | American Elm (Ulmus americana) in Wethersfield from Jan 1945 to Jan 1953 |
| | | Austrian Pine (Pinus nigra) in Plymouth from Apr 2013 to Oct 2013
also co-champion from Apr 2011 to Apr 2013 |
| | | Bayberry (Morella caroliniensis) in Westport from Jan 2020 to Nov 2021
also co-champion from Sep 2016 to Jan 2020 |
| | | Black Birch (Betula lenta) in Middletown (co-champion) from Jan 1993 to Dec 1993 |
| | | Buart (Juglans × bixbyi) in Chester (co-champion) from Nov 1998 to Nov 2008
also champion from Aug 1988 to Nov 1998 |
| | | Common Hoptree (Ptelea trifoliata) in Branford from Jan 1967 to Jan 1967 |
| | | Common Hoptree (Ptelea trifoliata) in West Hartford from Apr 1991 to Sep 1995 |
|  | | European Larch (Larix decidua) in Greenwich from Jan 2020 to Jan 2025
also co-champion from Oct 2013 to Jan 2020 |
| | | Gray Birch (Betula populifolia) in Colchester (co-champion) from Apr 2012 to Sep 2016 |
| | | Green Ash (Fraxinus pennsylvanica) in Glastonbury (co-champion) from Nov 2021 to Jan 2025 |
| | | Hardy Orange (Poncirus trifoliata) in Stonington from Apr 2011 to Jan 2020 |
| | | Long-beaked or Bebb Willow (Salix bebbiana) in New London from Apr 2012 to Feb 2016 |
| | | Noble Fir (Abies procera) in Pomfret (co-champion) from Apr 2014 to Nov 2014
also champion from Oct 2013 to Apr 2014 |
| | | Norway Maple (Acer platanoides) in Old Lyme from Apr 2012 to Nov 2015 |
| | | Norway Spruce (Picea abies) in Salisbury from Nov 2014 to Jan 2025 |
| | | Oneseed Hawthorn (Crataegus monogyna) in Old Saybrook from Oct 2020 to Nov 2021
also co-champion from Jan 1991 to Sep 2016 |
| | | Paper Birch (Betula papyrifera) in Hartford from Jan 2010 to Apr 2011 |
| | | Pawpaw (Asimina triloba) in Hartford from Apr 2012 to Oct 2012 |
| | | Peach (Prunus persica) in Madison from Jan 2010 to Apr 2012 |
|  | | Poison Sumac (Toxicodendron vernix) in Glastonbury (co-champion) from Apr 2011 to Jan 2020 |
| | | Red Maple (Acer rubrum) in Guilford (co-champion) from Jan 2020 to Jan 2025 |
| | | Serviceberry (Amelanchier arborea) in Glastonbury from Jan 2010 to Jan 2020 |
| | | Silver Maple (Acer saccharinum) in East Hampton from Oct 2013 to May 2015 |
| | | Striped Maple (Acer pensylvanicum) in Glastonbury (co-champion) from Jan 2020 to Oct 2020
also champion from Sep 2016 to Aug 2017 |
| | | Sugar Maple (Acer saccharum) in Norwich from Sep 1984 to Sep 1984 |
| | | Texas Redbud (Cercis canadensis var. texensis) in Windsor from Apr 2012 to Dec 2017 |
