This section of garden plants starting with the letter O, includes biennials, perennials, bulbs and shrubs, bedding plants, flowers.
Oenothera - Good perennial version of the Evening Primrose.
Onoclea; Ononis; Onopordum;
Orchis; Origanum; Ornithogalum; Orontium;
Osteospermum Whirlygig Type | Oenothera - the Evening Primrose.
Oxalis In some places Oxalis is seen as a weed - but there are different types suited for the garden or rockery.