Retinal detachment is a very serious eye condition that happens when the retina separates from the tissue around it. Since the retina can't work properly under these conditions, you could permanently lose vision if the detached retina isn't repaired promptly.
Plant Hardiness. Cannas are reliably hardy as far north as Zone 7, which includes New Yorkâs Long Island, Virginia, the Delmarva peninsula, southern Tennessee, mid-state Missouri, southern Oklahoma and parts of the Texas panhandle, as well as patchy areas of the Sierra Nevadas and West Coast mountain ranges.
Hardiness refers to a plant's ability to tolerate temperature. The USDA Plant Hardiness Zone map divides the United States into zones according to the average minimum cold temperature. A hibiscus brought to Illinois from Southern Florida will not survive outdoors all year due to its hardiness. Most of Illinois is classified zone 5. Plant material listed for this zone is able to survive the average minimum temperature between -10Â° and -20Â°F. Zone 5 has been further divided into 5a and 5b. Zone 5a average minimum temperature is -15 to -20Â°F, and zone 5b average minimum temperature is -10 to -15Â°F.