With its deep roots, the hydrangea anchors itself firmly in the ground and absorbs not only water but also trace elements. If the roots become rotten or are too badly damaged by careless transplanting, the root system can no longer fulfill its important task.
How are hydrangea roots structured and how do they work?
Hydrangea roots are shallow-rooted with a hard central stem and many fine root branches. They absorb water and trace elements, but are sensitive to waterlogging and damage when transplanting. Climbing hydrangeas also form adhesive roots to anchor themselves to facades or trees.
The structure of the hydrangea root
The hydrangea is a shallow-rooted plant, which means that the roots of the hydrangea do not extend very far into the ground. A special feature of the hydrangea root is its hard central stem, which can often only be separated with a saw when propagated by division. The hydrangea develops many fine root branches around it, which are responsible for feeding the plant. When moving the plant, care must be taken to damage the fine root system as little as possible to ensure that the plant grows well.
Waterlogging, the enemy of the roots
If your hydrangea wilts even though you water it sufficiently, waterlogging may have damaged the roots. Root rot is caused by a fungus whose growth is encouraged by too much moisture. The root system dies. You can recognize the infestation above ground by the yellow-colored, limp, drooping or dried leaves. The plant cares and only produces weak shoots and hardly any flowers.
Prevent root rot
If the deeper soil layers in your garden are heavily compacted, excess rain and irrigation water cannot seep away and build up. The hydrangea is permanently in water and there is a risk of root rot.
A drainage layer made of coarse sand or gravel, which is placed in the planting hole before the hydrangea is inserted, can help. Since the hydrangea has very specific substrate requirements, you should then fill the planting hole with special hydrangea or rhododendron soil. Do not mix this substrate with sand or gravel as is often recommended. It then no longer stores enough moisture, which is important for the hydrangea to thrive.
Adhesive roots make climbing hydrangeas grow tall
Some hydrangeas are sticky root climbers. They form adhesive roots with which they can anchor themselves to facades or trees. If you take a closer look at a branch of the climbing hydrangea, you can see that the plant only forms these roots on the side facing away from the light. Upon contact with the earth, for example when a tendril falls and rests on the ground for a long period of time, the adhesive roots often transform into soil roots.
Tip
Adhesive roots can only be formed by young shoots. Branches that are already woody no longer form adhesive roots. That's why it's important to additionally support large climbing hydrangeas with a scaffold.
