|Received an orange tree spring of '05(maybe mandarin orange), over fertilized it - burnt the whole crown - at the top of the tree it looked like it may have been grafted. we cut off all the dead (the whole head/crown) and it sprouted. Now 9/06 it looks like it did when I first got it. But it never flowered. House plant, south facing window. Is it a graft? will it fruit orange? thanks grace|
|Mandarin trees are usually grafted onto sour orange tree root stock so your tree is still technically a citrus tree and as such has the potential to produce flowers and fruit. It probably won't flower until it's about 3 years old. Continue giving it good care and you may end up with a few sour oranges. Even if you don't like the fruit, the fragrant flowers will reward you 2-3 times a year.
Now that you know that over-fertilization is easy to do with containerized plants, how about using a water-soluable fertilizer (such as Miracle-Gro or Peter's), diluting it to half-strength, and applying every 3-4 weeks all year around? This will eliminate the chance of over-feeding and the resulting salt burn.
Best wishes with your citrus!