Hydrangea macrophylla (synonyms/also known as: Big Leaf Hydrangea, French Hydrangea, Hortensia, Milflores, Christmas Roses, Mophead Hydrangea or Snowball Plant). The specific cultivar may be difficult/impossible as there are thousands of 'too similar' ones but, the care is typically the same. If it started blooming now, it could be a rebloomer cultivar such as from the Endless Summer Collection, the Together & Ever Collection, the Let's Dance Collection, etc. The stems should now have spring 2023 flower buds inside the ends of the stems. Deadheading is not required but it can be done at any time of the year that pleases you. I never deadhead them but if a plant has a leaf fungal disease that reoccurs, consider deadheading it in the fall so any spores found in the blooms end in the trash can. However, any pruning activities should be restricted to just a few weeks after the last bloom opens in spring. Pruning is not required other than to remove dead wood by the end of June in Il or even in July. Maintain 3-4" of mulch at all times. Your last fertilizer application should have already happened; it should occur 3 months prior to your city's average date of first frost so for Oak Brook, the average date of first frost is around the 3rd-4th weeks of October and thus your last application of a slow release fertilizer should happen around the 3rd-4th weeks of July. You can fertilize after your average date of last frost; for Oak Brook, that falls around the 2nd-3rd weeks of May. They look happy there.
