2020 Year of the Hydrangea!

The National Garden Bureau, the non-profit information and marketing arm of the gardening industry, has chosen the hydrangea shrub as one of this year's "Year of” honors.

For dramatic color and presentation in the garden, the hydrangea shrub is a real winner. While hydrangea are native to Asia and the Americas, the hydrangea was first cultivated in Japan.  Many varieties are zone hardy and can be successfully grown in NW Wisconsin.  Some varieties can be grown in pots.

The classic Bigleaf hydrangea likes early day sun and afternoon shade, they provide big bloom heads in a variety of colors from pink to blue dependent on the pH and minerals in your soil.  Lowering the pH to acidic may be all that is needed to make the natural iron in the soil change a pink bloom to a blue. Use aluminum sulfate to change the pH but with care as too much can affect the foliage and surrounding plants. Endless Summer is a popular variety of Bigleaf hydrangea. Prune after blooming in late fall to control the size of the shrub.  Where winters are harsh, pruning the stems to the ground may be advisable.

Where there is more intense sun and drier conditions the Annabelle variety, a Smooth hydrangea, will give you white to creamy, sometimes pinkish, flowers. This variety blooms on new growth so prune to ground or a few inches above in late fall or early spring to avoid leggy and drooping stems.  The blooms on these plants can be so large and heavy they can be weighed to the ground or forced to the ground by heavy rain. I have used removable wire edging fence around the plant to help support the heavy blooms.

For a dramatic cold hardy variety with large cone shaped flower heads try Panicle. This variety grows tall on woody stems and can be shaped into a single stem small tree (best if purchased as a tree). Popular varieties are Vanilla Strawberry and Limelight.  While some varieties of panicle can be pruned to the ground, for larger shrubs or tree shape, this variety should not be pruned to the ground except for unwanted, dead or diseased stems.

The Oakleaf variety is better suited to zone 5 and warmer climates. This variety can be grown in pots and wintered indoors in NW Wisconsin.

Hydrangea bloom from mid to late summer and into the fall. The bloom heads make wonderful additions to large bouquets of cut flowers or a bouquet by themselves. Some varieties also make wonderful dried flower bouquets. Cut the blooms at the peak of color as some color will be lost in the drying process.

For more information on hydrangea, check out:
https://ngb.org/year-of-the-hydrangea/
https://milwaukee.extension.wisc.edu/files/2016/11/HydrangeaBlues.pdf

Article by MGV Pam Davies
Photos by National Garden Bureau