I accidently overfertilized a new magnolia tree that was planted this spring. I used fertilization spikes. I used 5 and should only have used 2 at the most. I also drove them into the ground way too close to the trunk. Less than a week later, the leaves were turning black and falling off. Even leaves that aren't turned black are falling off. Is there anything I can do that will save the tree? I tried to dig the spikes back out, but they had already dissolved into the ground. I have been watering excessively to try to wash the fertilizer out, but am not sure if there is anything else I can do. Please help!