Q&As/Flowering Shrubs and Trees/Caring for Rhododendrons
I was shifting a small rhododendron that I had planted some months before, and I noticed that grass grub were nestling in the roots. Can grass grub damage rhododendron roots and if so, what is the best treatment for them?
Firstly, well done for checking the roots of your plant before moving it to a new location. It is a good way to check the condition of the plant and if there are any rots or insect visitors on the roots. Grass grub usually prefer grass roots, but to be on the safe side, you can buy a product called Diazanon from your local garden centre, which comes in granular form and can be easily applied. Just be sure to follow the instructions on the manufacturer’s packet.
The key to successful rhododendron cultivation is to ensure there is a nice thick layer of mulch around the base of the tree for 12 months of the year. This stops the soil from drying out especially in summer, and keeps the soil from becoming too wet in winter. You can also do this with a layer of compost, then add a layer of bark on top. Be sure to reapply in summer when necessary or when it has broken down into the soil. Fertilise rhododendron in spring with Daltons Premium Acid Fertiliser at six weekly intervals right through till summer. Then reapply again from late February through till April.