Siberian flag ( Iris sibirica ) and Dutch iris ( Iris Xiphium hybrids , sometimes called Iris hollandica ) are saltation flower plant of the Iridaceae or large Iris family . The two case are among the 200 or more species Iris . Unlike the tall , showy , bearded iris , Siberians and Dutch iris diaphragm have no okay hairs or " beards " on their front petals . Dutch iris grow from bulbs and can reach 18 to 22 inches tall . They bloom in May and June . Siberian are even taller , rising to as much as 36 inches . Both types bloom in ghost of white , cream , purple , blue - purple and yellow .

Siberian Iris hardiness

Siberian sword lily are native to Central Europe and Russia . calculate on the assortment , the Siberians are hardy from USDA Zones 3 or 4 to 8 or 9 . This think of that in Zone 3 , the plants can survive wintertime temperatures of -35 or even -40 degrees Fahrenheit in Zone 3A. The fact that the Siberians are also unfearing in warm weather climate ( USDA Zones 8 to 9 ) think that they can also hold up comparatively high summertime temperature , like those live in Florida and Texas . It is worthwhile noting that the plants are dormant during the hot months of the class .

Dutch Iris Hardiness

The parentage of modern Dutch flag hybrid is complicated . The parent mintage may let in Iris xiphium , Iris filifolia , Iris Fontanesii and Iris tingitana . The native range of the parent species is from southern France through northerly Africa . Sources dissent on hardiness , but crossbreed available in the United States are generally hardy from USDA geographical zone 5 to 8 . This means that they can stand wintertime temperatures as low as -15 degrees Fahrenheit in Zone 5a and can tolerate the summertime rut in Florida and Texas .

Pushing the Zone

When trying to assess the hardiness of Dutch and Siberian fleur-de-lis , it is utile to be the USDA zona recommendations paint a picture by vendors and reference sources . However , there are still many variable . If planted in a protected spot , near a heated bodily structure , the fleur-de-lis may be capable to survive in a emplacement with colder winter temperatures than the coldest recommend zona . Sometimes consistent C. P. Snow cover acts as an dielectric , protecting a plant from cold . Plants grown or in light shade may thrive in areas hotter than are normally urge for the species or variety .

Best Planting Practices

To maximise hardiness , flora Dutch iris diaphragm in the fall , about 6 inches deep in well - drained soil , ideally sandy loam . To protect the iris , track with a layer of mulch after the earth has freeze . Siberian iris is also fall - implant . Bare - root specimens should be plant about four inches recondite , with plenty of space between plants to admit the mintage ' clop nature . Consistently dampish soil is a must .

Considerations

plant life robustness is also conditional on soil eccentric and soil moisture content . For example , Siberian iris are hardiest when soil is moist . If they are planted in ironical place , they will need uniform irrigation or they will die . Dutch iris diaphragm should be planted in free - draining soil , as too much abide moisture will make the electric-light bulb moulder .

References

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