Saturday, January 23, 2010

KTRS 550 Inside Out Show Plant of the Week January 23 2010 Smooth Hydrangea

Head over Heels For Reliable Hydrangeas (or Solve your soggy garden problems with a Home Grown (Native) Option!)

A great rain garden worthy option, Smooth Hydrangea is a delightful native American that appreciates the wet/ dry cycle in Missouri’s natural and cultivated spaces.

She is adaptable to soil types and moisture levels once she is established.

Because she flowers on the current season's wood, she is also bloom reliable.

She is naturally found working on bank stabilization projects along Missouri’s banks and streams making her both a water and soil conservationist! (Perfect for rain gardens!)

Her foliage color is variable depending on the light levels, the time of year and the specific setting. During the spring and summer, her foliage can be described as a misty gray or army camouflage green or even a pale apple green.

In the fall, her color varies as well, ranging from a from a pale sun bleached blonde to toasty warm gold tones.

The leave size is also dependant on age and time of year but a single leaf can be as much as 6” long and fairly wide. Her texture is generally considered medium /bold but less so when compared to her sister Oakleaf Hydrangea and her other more distant relatives.

There is a cultivated form. ‘Annabelle’ that has been widely available for many years. Said to be a naturally occurring cultivar discovered in the wild near Anna, Illinois, she does sport exceptionally large showy white flowers that are easy to spot, even at a distance! She is also equally cold hardy as the species.

New to the market in 2010 is a pink form of H. ‘Annabelle’, called 'Invincibelle™ Spirit'. It will be interesting to see is this pink bloomer is as hardy and carefree as the white flowering 'Annabelle'. ( Click here for details or for Additional information)

Care Factor Rating: 1 Hydrangea arborescens / Smooth Hydrangea is very drought tolerant but must be watered regularly till established. Her good looks will suffer some but not permently during extended dry periods.

To maintain her in her most natural form and upright habit, minimize any pruning to just removing damaged shoots. The removal of spent flowers in late winter is common place but not necessary. Caring for her this way does offer a slightly more manicured appearance.

Pruning the occasional damaged or dead shoot is best done after foliage has completely expanded. This is because until the plant completely re-hydrates it is difficult to identify true winter damage or dieback from superficial damage until the shrub has fully leafed out. This can be as late as early summer. At that time most failed stems will be well hidden with foliage and probably be a minimal concern. This is a reliable bloomer that blooms every year on new growth so even if there is a very harsh winter and total dieback to the ground, all new shoots will emerge and flowering will still occur.

All phases of the flowers are considered to have attributes that provide some interest, even in the winter so leaving blossoms intact from initial bloom till the following late winter / early spring is typical management practice. (The flowers are frequently used in arrangements, both fresh and dried.)

If excessive flower size on ‘Annabelle’ is a concern, instead of removing just spent flowers, also trim her woody shoots back 1/3 in early spring each year before leaf break. This will encourage lateral branching, reduce flower size and increase bud count. This helps reduce “ sagging” flower heads that droop after rain and helps make the flower size more proportionate to the shrub size. This will also slightly change her form. This type of annual pruning may reduce overall size of the shrub over time and decrease shoot spread to some degree. This care technique increases her CFR (Care Factor Rating) to 2 for ‘Annabelle’ as it creates a slightly higher maintenance situation that is not needed for the health of the shrub.

No comments: