Phormium - 4L

Phormium, a native New Zealander, is a relative newcomer to the Northwest garden scene. It has long been grown in California as a strong growing upright and dramatic ‘ornamental-grass-on-steroids’ accent plant. Since its look tends to sell itself, this little blurb about Phormium is mainly to acquaint you with the varieties Portland Nursery usually stocks and to dispel some common misconceptions about its cultural care.

A peek at the Sunset Western Garden Book entry on the subject will show a low end zone rating of 7-9 (Portland is in zone 6 by Sunset zoning system) and warns of freezing potential in zones 5 and 6. While it is possible for Phormium to freeze in temperatures of 20 degrees and below, a quick look around town will reveal that freezing is not an inevitable destiny for Phormium here. A few cultural provisos will help.

Though this plant is often part of the California drought gardening palette, we recommend adequate water and fertilizer in our area to encourage a good deep root system. Our winter waterlogged heavy soils in combination with freezing temperatures can be deadly to a poorly rooted Phormium, but where plants experience improved soil drainage, regular water through summer and protection from desiccating winds in winter, New Zealand Flax will thrive. Planting early in the season to ensure plenty of rooting time can help as well. But, if Mother Nature throws a real arctic event we have to be philosophical.

An advantage we do have as a cooler growing area for Phormium is that the color in the foliage stays dark and full sun exposure tends not to bleach out even the lighter colors in the variegated varieties. They all make striking and unusual accents to our gardens.

All keep their leaves in winter, thrive in sun to part shade and perform well in containers, alone or with other plants.