Crossville Chronicle, Crossville, TN

July 29, 2013

PLATEAU GARDENING: Re-blooming hydrangeas and hummingbirds

By C. Rae Hozer
Chronicle contributor

— Today, hydrangeas are a hot landscape plant. Breeders are busily producing new and different kinds. While childhood images of this heirloom shrub growing in grandma and grandpa’s yard have always made hydrangeas a sentimental favorite, it was the introduction and heavy marketing of remontant (repeat-blooming) types just before the start of the millenium that lit a fire under this segment of the nursery industry.

Up to that point, most traditional bigleaf hydrangea varieties offered for sale bloomed on old wood in May and June. Pruning at the wrong time (after July 31) and weather events like early autumn frosts or late spring freezes could wipe out flower buds from the prior year. As a result there would be few or no flowers in the subsequent season.

Things changed when plantsman Michael Dirr of the University of Georgia saw a mophead style bigleaf hydrangea blooming in September 1998 at a wholesale grower in Minnesota. The time of bloom indicated that H. macrophylla specimen was flowering on new wood. Dirr successfully tested this cultivar named "Bailmer" (which was later marketed as "Endless Summer") and other mophead style bigleaf hydrangeas that reportedly were reblooming types — H. macrophylla "David Ramsey," "Decatur Blue," "Oak Hill" and "Penny Mac."

Once they became widely available, gardeners growing these remontant types would not lose every flower to winter kill and/or frost damage. If one of these plants was mistakenly cut to the ground in late winter, as is standard procedure for hydrangeas that bloom on new wood like the PeeGee hydrangea (Hydrangea paniculata "Grandiflora"), smooth hydrangea (H. arborescens "Grandiflora") and climbing hydrangea (H. anomala petiolaris), it wouldn’t be catastrophic. There would still be some blooms.

Dirr and others also identified varieties of bigleaf hydrangeas, which bloom repeatedly on old wood. They entered production at that time, as well. These introductions provided homeowners and landscapers new hydrangeas which flowered for many more weeks than those available previously. Selections in this group of "free-flowering" hydrangeas include H. macrophylla with names like "Fugi Waterfall," "Mme Emily Mouillere" and "Nikko Blue."

The only downside to so many new and improved hydrangeas in the nursery industry is that some beautiful old-type hydrangeas, which bloom more inconsistently, may be edged out of production as homeowners and landscapers put their money on hardy, re-blooming hydrangeas that reliably flower throughout the summer and into the fall year after year.

Feed migrating hummingbirds

Ruby-throated hummingbirds from Tennessee begin heading south in July. These little flying jewels spend the winter in Central America. They feed on insects and plant nectar to build fat reserves. Each bird needs to double its weight to fuel the migratory trip. The males start out in mid-July. Females and immature nestlings remain a few weeks longer to take advantage of available nectar stations and flowers.

Hang up an extra feeder for hummers coming through on the first leg of their flight south to the shores of the Gulf of Mexico. Here is a recipe for sugar water nectar:

Heat water to boiling in a microwave. Add sugar and stir until it dissolves. Cool. Fill feeders. The proportions are four parts hot water to one part white granulated sugar (do not substitute brown sugar, honey or artificial sweetener for granulated sugar and do not add red food coloring). For a small batch, use two cups water and half cup sugar. Four cups hot water and one cup granulated sugar makes a larger batch. Store any extra nectar in a glass container in the refrigerator up to two weeks.

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Plateau Gardening is written by Master Gardeners for gardeners in Tennessee’s Upper Cumberland Region.  Contact UT Extension Cumberland County at P.O. Box 483, Crossville, TN 38557 (484-6743) for answers to horticulture questions, free publications and how to become a Master Gardener. Send email comments or yard and garden inquiries to Master Gardener Rae, MGardenerRae@frontiernet.net.