I have these hydrangeas from last year and I saw that they started growing new cuttings at the bottom. Now you can see that the older ones are the taller ones and I was wondering if I can cut them and make new cutting that way. Also make the plant bushier. If I can how should I do it, directly to the soil or put them in the water first?
These are not cuttings, they are simply new growth coming off the roots of the plant, and as such, are not suitable for propagation purposes. You can propagate hydrangeas though, and there are three ways to do it; soft, semi ripe or hard wood cuttings, and all need to be of some length, not just little buds. Each type of cutting is taken at a different time of year and their treatment is different. This link https://www.rhs.org.uk/advice/profile?pid=122 has embedded links giving precise instructions as to how and when to collect hydrangea cuttings and what to do with them - scroll down to propagation. Depending where you live, if its somewhere that has very hard winters, the hardwood method may not be viable if the ground is always frozen in winter.