If a hydrangea has grown too big, you can divide the small shrub and put the two smaller plants back in a new location. However, this work requires some strength and time, as the hydrangea develops a compact center piece inside the root ball that can only be separated with a saw.
Digging up the old hydrangea
You can shorten very large hydrangeas by about a third before doing this. Please note, however, that you will then often have to do without the attractive flower decorations in the following vegetation period, since most hydrangeas already flower in the previous year.
Follow these steps:
- Dig a small ditch in a ring around the hydrangea. The distance to the main shoot should roughly correspond to the crown diameter.
- Dig up the root system as extensively as possible.
- If you have dug deep enough, the compact root ball can be easily pulled out to the side.
- With very large plants, a lever can be helpful to get the hydrangea out of the ground unharmed.
Dividing the Hydrangea
Then saw through the hard middle section of the hydrangea with a sharp saw. To prevent germs from entering the plant via the open cut surface, you should thoroughly clean the saw blade before doing this work.
It is then advisable to dust the interface with charcoal powder. Wrap the rhizome tightly in burlap to keep it from drying out.
Planting in the new location
The planting hole should be significantly larger than the roots of the divided hydrangea so that you can spread them freely in the planting pit when inserting them. In heavily compacted or loamy soils, it is advisable to put in a drainage layer of coarse gravel and sand before planting the hydrangea.
When planting large hydrangeas, it is helpful to have a second person hold the straightened plant while you gradually fill the pit with substrate. Apply soil carefully and water the hydrangea well. In summer in particular, the divided and transplanted hydrangea must be watered regularly so that it takes root well and is not damaged.
tips and tricks
Mix some of the soil from the old planting site into the substrate that you use to fill in the new planting hole. The hydrangea then grows back particularly quickly.