- Abelmoschus esculentus - Cramers Okrazilla
- Achillea - Fireland
- Achillea - Terra Cotta
- Achillea millefolium - Cassis
- Achillea millefolium - Colorado
- Achillea millifolium - Weiss Wonder
- Achillea ptarmica - Pearl Reselected
- Aconitum arendsii
- Aconitum carmichaelii
- Adenophora - Amethyst
- Agastache 'Blue Boa' Year 1 Year 2
- Agastache 'Blue Fortune' Year 1 Year 2
- Agastache - Cotton Candy
- Agastache - Golden Jubilee
- Agastache - Sangria
- Agastache - Summer Sky
- Agastache barberi - Tutti Frutti
- Ageratum - F1 Blue Horizon
- Ageratum - F1 Tall Blue Horizon
- Ageratum - High Tide Blue
- Ageratum - High Tide White
- Ageratum houstonianum - Blue Bouquet
- Ageratum houstonianum - Red Top
- Agrostemma - Contessa Pale Pink
- Allium - Experiment No. 1
- Allium - Experiment No. 2
- Allium - Experiment No. 3
- Amaranthus - Aurora
- Amaranthus - Elephant Head
- Amaranthus cruentus - Giant Copperhead
- Amaranthus cruentus - Red Cathedral Superior
- Amaranthus cruentus - Tower Green
- Amaranthus cruentus - Twin Towers Green
- Ammi majus - Graceland
- Ammi majus - Queen of Africa
- Ammi majus - White Wonder
- Ammi visnaga - Casablanca
- Ammobium alatum - Bikini
- Anaphalis margaritacea - New Snow
- Andropogon - Silver Sunrise
- Anemone - Bicolor Blue Shades
- Antirrhinum / Snapdragon: Many cultivar production trials here
- Aquilegia caerulea - Kirigami Mix
- Aquilegia vulgaris - Christa Barlow
- Aquilegia vulgaris - Rose Barlow
- Armeria - Joystick Red
- Armeria pseudarmeria - Joystick Lilac Shades
- Aronia arbutifolia - Brilliant
- Artemesia annua - Cramers’ Yardstick
- Asclepias curassavica - Silky Deep Red
- Asclepias curassavica - Silky Gold
- Asclepias curassavica - Silky Gold
- Asclepias curassavica - Silky Gold
- Asclepias curassavica - Silky Scarlet
- Aster: Many cultivar production trials here
- Astilbe x arendsii - Grande 2 years
- Astilbe x arendsii - Grande 1 year
- Astrantia 'Roma' year 1 year 2
- Astrantia major - Ruby Cloud 2 years