Diploids and Tetraploids: A diploid has 22 chromosones and a tetraploid has 44. If you're thinking of hybridizing, you must cross a diploid with a diploid or a tetraploid with a tetraploid.
Evergreen, Dormant and Semi-evergreen. These terms describe what happens to the foliage during the winter. Evergreens try to grow whenever it turns warm; Dormant varieties die completely to the ground until spring; and Semi-evergreens are somewhere in between. In general, dormant varieties are more cold hardy...although even evergreen types will do fairly well....particularly if mulched for the winter. Customers in zones 9 and 10 (find your zone on our Plant Hardiness Zones page), should probably stick to evergreen or semi-evergreen varieties. Since all of our plants are field grown they have survived through zone 5 without any problems.
Rebloomer. Almost all of the varieties we sell are described as rebloomers in most catalogs. There is a wide variation from type to type, however. Some have a fairly long blooming period; some have a distinct second bloom period and a few have some blooms most of the season. This feature is also heavily influenced by growing conditions....so we've decided not to make any claims regarding this characteristic. We can tell you, however, that our experience indicates most varieties listed as rebloomers have, at best, only a few sporadic blooms occuring after the main bloom period.