If I had a penny for every time someone comes into the garden center where I work (Estabrook’s) and asks me why their big-leaf Hydrangea (Hydrangea macrophylla), such as ‘Endless Summer’, isn’t blooming, I would be a wealthy lady. But let me clarify – this common frustration is primarily isolated to hardiness Zones 5 and 6. The exasperation is further aggravated by bare stems in spring that remain eyesores for months until the reality hits that they are actually dead. I took this photo in mid-June. Who needs that emotional rollercoaster?!
Mountain Hydrangea ‘Tuff Stuff’ (Hydrangea serrata) is radically different from macrophylla. Usually by May (depending on your zone), the bare stems quickly start breaking leaf bud and flushing out in foliage. Flower buds begin forming in June. Here is a picture of one of my ‘Tuff Stuff’ I took on May 31. ‘Tuff Stuff’ keeps repeat blooming through the summer. Similar to big-leaf Hydrangeas, flowers can be blue or pink based on soil pH and aluminum availability. The next picture is of the same plant on July 7th. Note to self: this fall add elemental sulfur to soil to make the flowers blue.
There are a number of dazzling varieties in the Tuff Stuff series: ‘Tuff Stuff Red’, ‘Tuff Stuff Ah-Ha’ and ‘Tiny Tuff Stuff’. These are hardy in Zones 5 – 9; bloom on new and old wood; and do best in part sun – sun (I have grown them in part shade with good results).