Species southern blue flag
yellow-purple, iris-shaped flowers with pale-green stems, and leaves

southern blue flag

Iris virginica

The southern blue flag, Iris virginica, is a striking wildflower with bold, iridescent deep blue petals and a larger yellow "beard" that blooms in late spring and summer. It grows easily and is tolerant of a wide variety of soils, though it prefers wet, boggy areas. It grows best in full sun but can tolerate partial shade. The plant's long, narrow leaves add texture to gardens, along with its bright flowers. A great choice for meadows and bog gardens, this native plant can bring beauty and color to any outdoor space.

Cycle:

Herbaceous Perennial

Watering:

Frequent

Propagation:

Division,Seed Propagation,Cutting,Layering Propagation

Hardiness Zone:

5 - 9

Flowers:

Violet blue with yellow and white crested falls Flowers In Summer

Sun:

Full sun

Leaf:

Yes

Leaf Color:

green

Growth Rate:

Low

Maintenance:

Low

Salt Tolerant:

Yes

Invasive:

Yes

watering

Southern Blue Flag should be watered about twice a week. The soil should be kept moist but not waterlogged. Soggy soil can lead to root rot which can cause the plant to die. Once a month, if the soil has become dry, water until saturated. Make sure to not water the leaves, as this can cause the plant to become diseased. When watering, make sure to check to see how dry the soil is to prevent over or under watering.

sunlight

Southern Blue Flag typically needs full sun - at least 8 hours per day - for optimal growth. More sun is generally beneficial, although the plant can tolerate partial shade. Avoiding overly hot spots will help prevent sunburn and leaf scorch. If growing in an area that receives hot afternoon sun, morning sunlight or filtered sunlight may be more appropriate. Southern Blue Flag is adapted to cooler environments and grows best in areas with mild summers.

pruning

Southern blue flag (Iris virginica) should be pruned annually in the late winter or early spring, before new growth appears. Pruning helps promote healthy, new growth, removes spent flower spikes, and helps control the shape and size of the plant. To prune correctly, use sharp, sterile pruning shears to cut free any overly involved foliage. Remove any dead foliage and cut off the spent flower spikes. Cut off the weak or straggling leaves and stems at their base, taking care not to damage the base of the plant. Once the pruning is finished, the plant should appear more compact and structured.

Season

Fall
Winter
Spring
Summer
Sep
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Starts Flowering

Iris virginica typically starts flowering in late spring, usually in May or June.

Starts Flowering

Iris virginica typically starts flowering in late spring, usually in May or June.

Hardiness Map