'Lord Baltimore' Hardy Hibiscus or rose-mallow is the result of the
hybridization of Hibiscus coccineus, H. laevis, H. moscheutos, and H. palustris.
Based on the native range maps supplied by the United States Department of
Agriculture (USDA), all of these species are native to Maryland with the
exception of Hibiscus coccineus which has the northern most native range of
Virginia. This nearly sterile hybrid introduced in 1955 was the result of the
work of Robert Darby from College Park, Maryland. 'Lord Baltimore' is the
maternal parent to the 'Lady Baltimore' (US Plant Patent # 4271) cultivar which
was patented in 1977. Within the patent description for 'Lady Baltimore,' it is
declared that 'Lord Baltimore' in an open pollinated situation with natural
(bee) and manual delivery of pollen has resulted in a flower-to-seedpod ratio of
approximately 250 to 1. This means that 'Lord Baltimore' is essentially a
sterile hybrid that does not produce seed. The lack of seed production allows
'Lord Baltimore' to produce more flowers than other hardy hibiscus that must use
a large portion of their energy to produce seed pods. 'Lord Baltimore' is a
large perennial that has an appearance similar to a shrub in late summer. It
gets off to a slow start as it emerges late in the spring when compared with
many other perennials; however, it can grow to 4 – 5 feet or more in an average
growing season before dying back to the ground during the winter months.
Manually pinching the tips of the fresh growth in the early summer will reduce
the overall height of the plant, create a denser more compact habit and can help
reduce flopping of heavy stems. Planting in full sun is recommended to ensure
maximum production of flowers. Each of the vivid red flowers will grow to a 10"
diameter size; however, they will last only one day. The 'Lord Baltimore'
hibiscus grows well in zones 4 – 9 and should be pruned to a few inches above
the ground at the end of the growing season. On the University of Maryland
College Park campus, you may view this featured plant on the west side of the