Synonymous with the splendor of summer throughout the South, hydrangeas have been popular shrubs since the late 1800s. Most “genteel” gardens of the upper and middle classes during Grandma’s era boasted at least one in their garden.

Though they fell out of fashion for several decades, they have made a dramatic comeback as breeding programs in Europe and the United States have introduced various new varieties more suitable for home landscapes and lifestyle celebrities, like Martha Stewart, have sung their praises.

Most species of the genus Hydrangea are native to Asia with the first being imported into the United States from Japan in the 1750s.

The hydrangeas commonly grown in our state include bigleaf or French (H.macrophylla), which is the most popular; panicle (H. paniculata); oakleaf (H. quercifolia); mountain (H. serrata); smooth (H. arborescens); and climbing (H. anomala subsp.petiolas).

Two of these are native species to the Deep South, including Mississippi. Oakleaf, discovered by John Bartram in 1791, and smooth grows in woody areas in Warren County, spreading by stolons that form colonies.

Gardeners are often perplexed when their hydrangeas fail to produce spring blooms.

Dr. Wayne Porter, area extension agent for Lauderdale County, hydrangea expert and the author of the extension publication Hydrangeas for Mississippi Gardens, covers this issue.

Cold injury to buds in winter and early spring, drought in late fall or winter, too much shade, too much nitrogen fertilizer or pruning at the wrong time can all cause a hydrangea to not bloom the following spring.

Porter says gardeners always need to know what species they are growing and can usually obtain this information from the plant label or by asking the retailer if the label is not specific or attached.

They can do a little research about the variety before a purchase, then choose an appropriate site for planting and follow the cultural requirements necessary for the plant to thrive. Well-drained soil with lots of organic material (25-50 percent is recommended) worked into the planting site is important for all hydrangeas.

Most need at least four hours of morning sun with some afternoon shade but never deep shade conditions.

They need consistent soil moisture, particularly during the first year in the ground and during prolonged dry periods in late summer and fall when buds may drop off from too little moisture (same thing can happen with azaleas, according to Porter). However, they can root rot if drainage is poor. About 2 to 3 inches of mulch will help to retain soil moisture and keep weeds from competing with the plant for nutrients and water.

Pruning at the wrong time can also sabotage blooms.

Bigleaf (both mopheads and lacecaps), oakleaf and mountain varieties bloom on old growth and should be pruned right after flowering in early summer, no later than Aug. 1.

Most of these seldom need pruning but Porter mentions that large overgrown plants may benefit from cutting back 1/3 of old stems to the ground and removing flower heads from remaining stems to encourage branching that will improve vigor and increase next year’s blooms.

A new innovation has proven to be an exception to the Aug. 1 deadline. In 1998, a reblooming or remontant bigleaf hydrangea was identified, trademarked and commercially marketed as Endless Summer ‘Bailmer’. Endless Summer blooms on new and old wood so improper pruning or late spring frosts are not as big an issue.

The Endless Summer family now includes the original ‘Bailmer,’ ‘Blushing Bride,’ a lacecap called ‘Twist and Shout’ and ‘Bloomstruck.’

Smooth and panicle hydrangeas bloom on new wood so late winter or early spring is the time to prune these types.

They can be cut to any size desired and a second cut back after the initial flowering often stimulates a second round of blooms. Mississippi Medallion ‘Limelight,’ ‘Chantilly Lace,’ ‘Little Lamb’ and the new small ‘Little Lime’ are popular panicles. ‘Annabelle’ and ‘White Dome’ are smooth hydrangeas that also bloom on new wood.

The extension publications feature descriptions of 31 popular hydrangeas, of which 21 are bigleaf or French hydrangeas. Each description indicates if the variety was test grown at the Truck Crops Experiment Station, USDA Southern Horticultural Laboratory, by advanced Mississippi gardeners or researchers in other Deep South states with similar growing conditions.

All are excellent choices for our area.

Porter mentions Aldridge Gardens in Hoover, Alabama, as a great place to see several of the varieties mentioned in the publication including oakleaf hydrangea ‘Snowflake’ that grows 10 feet tall with huge panicles of double sepals that continue to open throughout the summer.

To learn more about hydrangeas go to the MSU Extension Service’s new website at extension.msstate.edu and type in the name of the publication Hydrangeas for Mississippi Gardens.