The Gardeners Almanac

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Pacific Coast Iris

Californicae-Pacific group:

Related Links

Week Numbers

Iris Overview

Coldframe

Collect seed

Compost

Division

Heating

Planting Out

Seed sowing

Soil pH

Overview:

Pale blue variety

 Dark blue variety

Pacific Coast irises are beardless clump-forming plants that grow to 600-900mm (24-36”) in height, and spread from 300-600mm (12"-24")

The foliage is usually evergreen, and the rhizomes are generally long and slender with a sparse root system.

The flowers have three outer petals (falls) and three inner petals (standards) with two to four flowers per stem, and appear from late Spring to mid Summer.

The colours range through blues, creams, purples, reds,and whites.

They will thrive in either full sun or partial shade, in moist soil ranging in pH from 5 -7½.

Plant culture is similar to other iris.


Cultivation:

Week 2:

Raise the temperature of autumn sown seedlings to around 7°-10° C (45°-50°F)


circa Week 12:

Once the plants have three or four leaves, transplant them into 70mm (3”) pots of lime-free compost.


Week 22:

Plant out plants sown the previous year into their flowering positions.

They require a sunny or dappled shade position and lime free soil.

They may produce their first flowers the following May, although early summer of the third year is more usual.


Week 30-35 >

After the flowers have died back, collect ripe seed and divide overcrowded clumps.

Otherwise cut the plants down when the leaves turn yellow.


Week 40:

Plants raised from seed will not be identical to the parent plant.

Sow seed 12mm (½”) apart in pots/trays of lime free seed compost and place in a cold frame to stratify - chilling is needed to break the seeds dormancy.