Fertiliser – Root Burn

Q: A couple of weeks ago, I put too much fertilizer on an English boxwood. Now the branches have begun to turn brown. Is there any way to save it?

A: Boxwoods, like azaleas, have a shallow root system – a net of roots just under the soil surface. That means they are both very sensitive to excess fertilizer. Unfortunately, once the fertilizer has penetrated to the soil around the roots, about all you can do is to flush it away with water. Too much water, though, could lead to root rot. Your best bet would be to spend a day delivering hourly soakings to the soil around the boxwood, then let it dry out for a week. Depending on how many roots were damaged by the salty fertilizer, the shrub might come back – – or it might not.