Gladioli are classified into five categories to indicate size. In the code, the first number indicates size. The diameter of the flower is measured as it grows normally without being flattened out in any way. This measurement is made on the bottom florets of the spike, which are generally slightly larger than those farther up.
| Code | Group | Flower diameter | |
| 100 | Miniature | under 2.5” | under 6 cm |
| 200 | Small | 2.5” – 3.5” | 6 - 9 cm |
| 300 | Medium | 3.5”- 4.5” | 9 - 11,5 (12) cm |
| 400 | Large | 4.5” – 5.5” | 11,5 (12) - 14 cm |
| 500 | Giant | 5.5” or larger | 14 cm or larger |
The number 516, for example, indicates a giant-flowered gladiolus.
© Irina Antipina, 2003-2012
