Pacific Coast Iris - 'Yaroona'
The Pacific Coast Irises or Californian Irises are beardless irises which are generally small, compact plants with slender, wiry rhizomes, with narrow grass-like leaves. Pacific Coast Irises are evergreen. They are a native iris of the west coast of the US, which is why I love them. They grow to a height of around 20cm to 45cm. Flowering occurs from early to mid-spring. Their flowers are some of the most stunning you will ever see. Bright bold colours with most flowers being bicoloured.
Pacific Coast Irises need to be grown in well drained slightly acidic soil (pH 5.5 to 6.5) that is moist but not wet. They need a sunny position but one that’s not too hot and dry. Aim for morning sun and afternoon shade. Ideal climate is one where the winters are wet, a touch of spring rain and a dry summer with a weekly watering. However, do not water during the hottest part of the day. Make sure you keep their root systems cool. This can be done with mulch or with other plants. I use Sweet Williams and Pansies. Once established these plants can withstand sub zero temperatures.
As the plants grow, they start to form a “donut” shape. You will start noticing this after approximately 4 years of growth. When this occurs, you need to divide your plant.
Pacific Coast Irises must be divided when they are growing. This occurs during later winter to early summer and mid-autumn to early winter. However, you must check the plant to ensure it is in this phase. To do this, you need to check the roots. Just gently remove some soil from the surface. You should notice white roots. If you do, it is time to divide your plant.
Pacific Coast Irises can also be successfully grown in pots.