Some people have rooted them in water, but many others (such as myself) have never been able to make this work. Susan Park Cole sent us the picture to the right demonstrating that it is possible to root hydrangeas in water. Occasionally roots form when one leaves an arrangement in water for a long time.Click to see full answer. In this way, when should you take hydrangea cuttings?Propagating Hydrangea Cuttings. Hydrangeas cuttings are generally easy to take but are slow to root, so it can be a problem getting them to survive over-winter unless they have rooted really well. I find it is best to take them in early summer, around July to ensure they get plenty of time to get a good head start.Likewise, how long do hydrangea cuttings take to root? 2 to 3 weeks People also ask, how do you grow hydrangeas from cuttings? Rooting Hydrangea Cuttings in Five Easy Steps Take a cutting from a branch of the hydrangea shrub about 5-6″ long. Remove the lower leaves of the bottom two leaf nodes. Cut largest leaves down to about half their size. Dip cuttings in rooting hormone (this is entirely optional) and insert into damp vermiculite or sterile medium. Water pot well and allow to drain. Can you take hydrangea cuttings in autumn?The best time to propagate Hydrangea cuttings is from spring when the plant is leafing out, to early fall when the leaves are still lush and green.