- H.M. engle & Son (1)
- H.M.Miller (1)
- Hains, Ben (2)
- Hall Brothers (1)
- Hancock, Jane (3)
- Harding Brothers Nursery (1)
- Harkett's Floral Nursery (1)
- Harman & Son, Seedsmen (1)
- Harnden Seed Co. (2)
- Harnden's Seed Store (1)
- Harrison Nursery Co. (5)
- Hartel, John G. (1)
- Hawks Nursery Co. (2)
- Hayes Seed House (2)
- Heikes, W.F. (2)
- Heinricher, E. (1)
- Heller Brothers Co. (5)
- Herrick Nursery and Seed Company (1)
- Herrick Seed Co. (1)
- Heubach, Walter (Muenchen) (4)
