| Cultivar | Group | Type | Hardy | Color | Bloom Time | |
|---|---|---|---|---|---|---|
|
‘Obsession’ | Holly Springs | evg | -5 F | Midseason | |
|
Octavian
(Rosenkavalier) | Robin Hill | evg | Midseason | ||
| ‘Ogon-no-Tsuki’ | Satsuki | evg | Zone 7, at least | |||
|
Oh Heaven | Hager | evg | -10 F | Midseason | |
|
Oh Heck | Hager | evg | Zone 7 | ||
|
Oh Look | Hager | evg | Zone 7 | ||
|
‘Oh My’ | Satsuki | evg | Zone 7 | Late | |
|
‘Oh My’ (Akamuji) | Satsuki | evg | Zone 7 | Late | |
|
Oh Nuts | Hager | evg | -10 F | Midseason | |
| Ohio | Chisolm-Merritt | evg | ||||
|
Oinomezame
aka:[Melody] | Kurume | evg | Zone 7, at least | Early | |
| ‘Okina Nishiki’ | Satsuki | evg | ||||
| Olga Mezitt | Mezitt | lep | ||||
|
‘Olin O. Dobbs’ | Dobbs | elp | -15°F | Purple,Red | Midseason |
| Olive | Maxwell | lep | -15°F | Pink | Very Early | |
| Omega
(Antoine) | Deckert | evg | ||||
|
Omen | Glenn Dale | evg | |||
| ‘Omoi-no-Maku’ | Satsuki | evg | ||||
| Omurasaki | Mucronatum | evg | Zone 7 | Late Midseason | ||
|
‘Onsho’ | Satsuki | evg | Zone 7 | ||
|
‘Onyo’ | Satsuki | evg | Zone 7 | Midseason | |
|
‘Oogocho’ | Kurume | evg | Zone 7, at least | ||
|
Oops | Hager | evg | -10 F | Midseason | |
|
Oouchiyama
(NA 45416) | Kurume | evg | Zone 7 | Purple,Red | |
|
‘Opal’ | Linwood | evg | Zone 7 | Pink-Light | Fall |
|
Opera | Glenn Dale | evg | |||
|
Oracle | Glenn Dale | evg | |||
|
Orange Carpet | Sommerville | dec | Orange | Early | |
|
Orange Ember | Sommerville | dec | Orange | ||
|
‘Orange Flare’ | Back Acres | evg | Pink,Yellow | Late | |
|
‘Orange Fluff’ | Holly Springs | evg | -5 F | Midseason | |
|
‘Orange Slice’ | Coleman | evg | Zone 7, at least | Early Midseason | |
|
Orchid Beauty | Linwood | evg | 0 F | Red,Purple | |
|
Orchid Belle | Beltsville | evg | Purple | ||
|
Orchid Empress | Kurume | evg | Hardy to -5 F/Zone 7, at least | ||
| Orchid Star | Kurume | evg | Zone 7, at least | |||
|
‘Orchido’ | Ring | evg | |||
|
‘Oriflamme’ | Glenn Dale | evg | Zone 7 | Purple | Late Midseason |
|
Orison | Glenn Dale | evg | |||
|
‘Oritani’ | Theum | lep | Hardy -15 F to -20 F. | Lavender | Early Midseason |
| Orphan Annie | TBD | elp | ||||
| Orpheus | Glenn Dale | evg | ||||
|
‘Osakazuki’
(Large Sake Cup) | Satsuki | evg | Pink | ||
|
Osaraku
(Penelope, Wilson #15) | Kurume | evg | -5 F | White,Pink,Lavender,Purple | Early Midseason |
|
Otome
(Maiden’s Blush) | Kurume | evg | Zone 7-9 | Pink | Early Midseason |
| ‘Otome’
(Maiden) | Satsuki | evg | ||||
|
‘Ouchiyama’ | Kurume | evg | Zone 7, at least | ||
| ‘Overture’ | Aromi | evg | Zone 7 | Pink-Dark | ||
| Cultivar | Group | Type | Hardy | Color | Bloom Time |