BloomStruck™ is the most free-flowering of the (5) cultivars in the Endless Summer Series at Heritage; the mophead blossoms have attractive medium to deep purple blue colors as can be observed in the photo on the above right.
Like all the H. macrophyllas at Heritage, the BloomStruck™ plantings are pruned annually in April-May and receive well automated surface (drip) irrigation. The majority of the plants went in the ground in 2014 with some relocations in 2016 when the Test Garden was established. One group of these 2016 plants went into quite sunny locations and quickly developed Cercospera leaf-spotting. In early autumn 2017 we moved these affected plants to two shaded locations and leaf spotting in 2018 was greatly reduced. This positive effect on leaf-spotting response was also observed in 2019.
Bloom Count & Quality
Flower development has been very good despite the vagaries of our weather – severe winter ‘snaps’ followed by an extended and chilly spring. Mid-summer flowering on BloomStruck™ old wood is strong with per plant bloom counts often exceeding (50). The only downside is the blooms are somewhat small – 3” to maybe 5”. Bloom color, owing to our adequate soil aluminum and low pH, produces the aforementioned attractive blue-purple tones.
BloomStruck™ does rebloom reliably but somewhat modestly unless encouraged by mid-summer pinch-pruning. In our location, late July pinching of non-flowering stems – and spent blossoms – appears to ‘trigger’ the production of new growth with tip buds having a high potential for developing an inflorescence by early autumn. Timing is critical and we will continue to conduct our pinching trials to further optimize this reblooming.
General Growth Characteristics
Overall growth of our BloomStruck™ has been very good in terms of plant form, average stem density and uniformity of branching. It is a medium size plant for us, nominally 4 ft high and wide and quite similar to Endless Summer – Original™. Growth is vigorous and plant form responds favorably following judicious pruning. A single low-volume application of a granular controlled release fertilizer is applied in early spring and all plantings receive drip – surface irrigation.
Given the already mentioned comments about sun exposure and Cercospera leaf spotting, our relocated BloomStruck™ are doing much better in the more shaded sites. One of our larger plantings is receiving highly diffused full-day sunlight and foliage there is totally clean.
Previous comments on leaf spotting is consistent with BloomStruck™. The plant does lose its leaves somewhat earlier than most of the H. macrophylla cultivars at Heritage. The photos below illustrate the leaf spotting associated with sun exposure.