The Master Gardener Articles

---

Hydrangeas

If you are looking for a woody ornamental plant adapted to full sun or medium shade and has outstanding flowering from June into the fall, look no further. Hydrangea has come into its own in recent years. A few years ago, there were only 9 varieties from 3 different species.  Because of extensive breeding and plant selection, there are now 66 varieties from 5 different species.

These 5 species include Hydrangea macrophylla, Hydrangea quercifolia, Hydrangea paniculata, Hydrangea serrate and Hydrangea arborescens.  Each species has its own unique characteristics. If you select a Hydrangea quercifolia you can expect repeat flowering into the fall from varieties such as ‘Endless Summer’, ‘Penny Mac’, ‘Oak Hill’ and ‘David Ramsey’. A dwarf variety is ‘Honli’. A red flowering form which is excellent for small spaces on the North side of the house. Another unique variety, of Hydrangea macrophylla is ‘Hanabi’ also called ‘fireworks’ which has very dark shiny green leaves. This hydrangea has the glossiest green foliage of all hydrangeas. The flowers begin as white and quickly mature to dark pink.

New cultivars emerging from Dr. Dirrs selections are Hydrangea macrophylla ‘Mini Penny’ (dwarf type) and ‘Lady in Red’, which has dark red stems with dark foliage and is mildew resistant. Hydrangea quercifolia (Oak leaf hydrangea) comes in the old stand-bys (‘Snow Flake’, ‘Snow Queen’ and ‘Alice’) but more recently dwarf selections are (‘Pee-Wee’, ‘Sikes dwarf’, ‘Amethyst’, ‘Little Honey’) which are coming to the market. They are more compact and are heavy flowers. ‘Little Honey’ is a gold leaf form which is a sport (selection) from ‘Pee-Wee’.

Research on hydrangea continues under the direction of Dr. Sandra Reed (Research Geneticist at the U.S. Arboretum Floral and Nursery Plants Research Unit in McMinnville, Tennessee. New cultivars will soon be added for your enjoyment.

For more information on hydrangea varieties, see a new book by Dr. Dirr, “Hydrangeas for American Gardens” or call the Union County Extension Office at 937.644.8117 and ask for George McVey, Extension Program Assistant, Horticulture, Master Gardener Coordinator.