Growing PCI on the West Coast (of North America) and Similar Climates

Plant PCI in early to mid spring or in the fall, when weather is mild and plants have new white roots.

Dig a good sized hole, mix about one third compost and a few wood chips into the soil around the hole, then gently tap the plant out of the pot, spread out the fine roots, and place the plant in the ground at the same height in the soil that it was in the pot. Mix more compost into the soil used to backfill around the roots. Tamp the plant in gently and firmly to make sure the roots are in good contact with the soil.

If your soil is not naturally acidic and well drained, make a raised bed with amended soil, using fine gravel and coarse sand to open up finer soils, or use a well drained garden soil mix nine inches to a foot deep, in a raised bed above the native soil.

Mulch around the plant with bark chips, to keep the roots cool in summer and warm in winter. Water the new plants in well, using a dilute fertilizer mix in the water.

Add a permanent label near the plant, and keep notes on where you planted which PCI. Do not rely on your memory. If you grow more than one or two different kinds, you will soon lose track of what variety grows where. Take notes. Put labels next to the plants.

Grow PCI in part shade, not full sun. Morning sun with midday and afternoon shade is good in most climates. When you are experienced with growing PCI in part shade, you can try sunnier locations.

During the first summer in your garden, water new PCI plants every week to two weeks, unless it rains regularly. Water PCI in early morning, or late afternoon to evening in hot weather. Do not water midday in hot weather; this is thought to promote fungi that kill PCI.

PCI are naturally adapted to xeric landscapes in Mediterranean climates. Once they have settled in, you will find that they need very little additional water in most temperate climates.

Fertilize in late winter or early spring with a good perennial fertilizer. You can also top dress each spring with compost and mulch.

In late winter, cut the leaves back to 4 inches tall with scissors, or if you have a natural planting with access for a mower, such as wildflower meadow, set the mower at 4 inches, and mow leaves when you mow the entire meadow. Do this before the new leaves lengthen on the new fans. After the new leaves emerge, cut off old leaves one at a time, carefully, to avoid damaging new foliage and flower shoots.

Rake all the cut leaves off and dispose of them. This reduces hiding places for slugs, snails, and unwanted fungi that can colonize dying leaves and damage the plants.


PCI require mildly acidic soil with good drainage. They are not wetland plants and do not like damp or soggy growing conditions, or alkaline soils or water. Yes, this is unlike many other iris, and it is very important to remember!


Farrel, Bill. 1998. Whatever happened to my PCIs? SPNCI Almanac, Spring 1998.

Hall, Gigi. 2007. The Pacific Coast Native Iris, SPCNI Almanac, Fall 2007.

Lacey, Louise, Editor. 1996. Pacific Coast Native Iris. Growing Native Vol. 7: 1, January / February 1996, #31.
This issue (#31) focused on PCIs, with three articles by Lewis Lawyer and Adele Lawyer. Printed copies are available from Growing Native. Order GN #31 by mail at: Growing Native, P O Box 489, Berkeley CA 94701. Cost is $6. This issue is not available online.

Lawyer, Adele. 1993. Cultural directions, SPCNI Almanac, Fall 1993, p 26.

Lawyer, Lewis. 1983. PCI culture part 1, seedbed through bloom, SPCNI Almanac, Spring 1983.

Ibid. 1988. To trim or not to trim, SPCNI Almanac, Fall 1998.

Ibid. 1995, Optimum time for transplanting, SPCNI Almanac, Spring 1995.

Lundberg, Mrs. Richard. 1996. PCI from start to finish, SPCNI Almanac, Spring 1996.