Bobo is one of the most compact paniculata hydrangeas, measuring hardly above 3' high and 4' wide after 10 years or so. The most compact is currently Fire Light Tidbit.
The bloom date varies depending on geographical location with southern locations blooming earlier than northern/Canadian location. On average, it should bloom time is average to slightly early when compared to most other paniculatas but it is not one of the earliest ones to bloom if that is what you were wondering.
Expect blooms anywhere from very late Spring to the summer time (that varies from year to year and many factors influence blooming time). Because they develop flower buds at those times, you should not do pruning at those times.
The blooms can be left on the plant for winter interest and let Mother Nature take care of them. If you do, they will very slowly fall down, probably about a year after the blooms opened, "plus or minus".
If you plant hydrangeas in a spot where it can achieve its size at maturity you should not need to do annual, regular pruning except to deadhead spent flowers (that can be done at any time) or to remove dead wood (any stems that do not leaf out by the end of March can be pruned all the way down). They produce flower buds inside the stems by the middle to end of Spring, depending on many factors including weather. Then they bloom shortly thereafter.
Paniculatas are the most sun tolerant hydrangeas and, in the northern states, can get full sun all year around. Grandiflora even becomes a small tree when grown in the northeast. The more sun that paniculatas get, the better they will perform provided they get adequate watering. Note: if one is located in the southern states, the leaves may fry and some respite is called for during the afternoon hours. Enough and frequent water is required in the summer months in some areas.
The first year, you do not need to fertilize them if they already have those round fertilizer pellets that the wholesalers use. Afterwards, you can give them about a cup of cottonseed meal, organic compost, composted manure or you can apply a general purpose, slow release, chemical fertilizer with a NPK Ratio of around 10-10-10. Since they are not heavy feeder plants like roses, they can just feed off the decomposing mulch and many people stop fertilizing once the plants are established... provided your soil has no nutrient deficiencies like sandy soil can have for example.
Try to maintain 2-4" of organic mulch (no rocks) up to or beyond the drip line at all times of the year.
Amend the soil regularly with garden sulfur, iron sulfate, greensand or iron-chelated liquids if your soil is alkaline and the plant's leaves show signs of iron chlorosis: the dark green leaves turn light green or yellowish, except for the leaf veins which stay dark green.
Here is more information:
https://www.provenwinners.com/...
The Spring Meadow Nursery patent notes that the blooms average about 10.5 tall and 6 inches wide. But they can be smaller in shade, bad environmental conditions) or when the blooms are more numerous.
https://patents.justia.com/pat...
