You have two options. It can be spread with a lawn fertilizer spreader but you have to be careful not to over-fertilize any surrounding plants. Divide the total amount of fertilizer needed between the holes. Cover the holes with a handful of soil or sand. Both Synchronicity and Milorganite are great balanced organic fertilizers that work with trees and shrubs.
Organic fertilizers are naturally slow-release.
It washes through the soil too quickly. To be effective, you need to understand a few things about root feeders. First of all, it is essential that they are not pushed too far into the ground. In fact, six inches is ideal. Because the probe is 2-3 feet long, it is tempting to push it further into the ground.