We fertilize your plants at the time of installation and we recommend you hold off fertilizing until the following year. We do offer an Annual Lanscaping Fertilizing service which you can contact us about if you are interested. The soil in Allen County tends to be made of clay and is therefore more alkaline than acidic. Some plants such as Boxwood, Holly, Dogwood, and Serviceberry benefit from an annual application of a soil acidifier plus iron mixture. Let us know if the leaves of your plants are yellowing as this is often a sign of chlorosis and an application of iron will improve this condition usually. There are other causes of yellowing leaves as well.