These last three types of Hydrangeas are special not just because most bloom off of old wood but because you can manipulate the color by changing the PH in the soil. In Chicago these hydrangeas will be very happy being some shade of pink. To make them more intense pink you can add lime (raise the PH over 7) and that would make varieties like ‘Lady in Red’, ‘Glowing Embers’ and ‘Homigo’ really pop with bright pink or red color. Lower the PH (under 5) and your ‘Nikko’, ‘Endless Summers’, ‘Blue Billows’ remind you of summers in Martha’s Vineyard. In Chicago it is a battle to keep your hydrangea more towards the blue side. So I do encourage people to know that pink works well here. You can change your PH with sulfur, coffee grounds or my favorite is aluminum sulfate (because the plant takes it up faster and you get better results). However, I personally like the purple flowers, those are the plants that I see that have set flower bud and are about ready to open, so I quick put aluminum sulfate by the roots.
Mophead Hydrangea, Big Leaf Hydrangea, Mac Hydrangea, Hortensia Hydrangea, Florist Hydrangea are all Hydrangea macrophylla. These are what people traditionally envision with the large blue spheres of color gracefully adorning the front of Colonial East coast homes or the masses of pink puffs in front of Midwest Victorian mansions. These are the flowers that many brides adore but cause so much heartache to even the seasoned gardener in the Chicago area. Deep within the industry some of these varieties have nicknames that I will not divulge, because “if you can’t say something nice then don’t say anything at all”. The core of the heartache is caused by the lack of reliable blooms. Most of these varieties bloom off of old wood only. And old wood often dies here during the winter. It is a must for gardeners to provide winter protection such as leaves or straw over the entire plant to maintain the growth from the previous summer to the next spring. However, there are some notable ones that say they bloom off of old and new wood such as the ‘Endless Summer’ ‘Let’s Dance’ and the ‘Forever and Ever’ Series. We tell our clients that you should still give protection and that these varieties have a tendency to bloom off of the new wood very late in the season. If you are willing to take the necessary precautions you do open up the door to more interesting varieties. ‘Glowing Embers’ will strive to be a vivid pink even in a low PH setting. The ‘City line’ series from Proven Winners are smaller more manageable plants. ‘Homigo’ noted for its constantly changing colors, no two blooms will be alike on this plant, a truly unique gift from Mother Nature. ‘Nikko’ is my favorite and long time running variety that when given the proper PH conditions it has brilliant blue color.
Hydrangea macrophylla normalis are an off shoot of the mophead varieties but have some infertile flowers that do not open creating a laceier look, hence why they are called Lace Caps. ‘Twist and Shout’ is part of the ‘Endless Summer’ Series and well received for it blooms off of old and new wood. ‘Lady in Red’ was created by Michael Dirr and has great fall foliage and striking red stems, but she really needs winter protection in Northern Illinois because she is a Southern Bell.
Mountain Hydrangea (Hydrangea serrata) like my ‘Blue Billows’ which I am always praying for a miracle that they will bloom even though they see no winter protection and every spring I am disappointed. If given all the right conditions I would have large Lacey round blues spheres of color that would looks so magnificent in front of our red brick Colonial. I should really call my maintenance crew to pour some leaves on them.
Now that you have been bombarded with all this information, (I thought this would be an easy blog to write, my staff laughed at my naivety) I will work on a chart for more clarity. Remember “Hydra(te)” is part of Hydrangea so they like to be given consistent moisture but hate to sit in standing water. Please contact me or comment on my blog if you have questions, I would love to help.