Hi, a little over 4 years ago I grew a grapefruit tree from seed (it was a white grapefruit line taken from the Kampong (david fairchild house and garden) in miami, with their permission. It sprouted nicely in a pot and I transferred it to the ground about a year later. About a year after that (2 year old tree), the top of the tree was broken by a falling pine tree branch. Before this the tree had exhibited the characteristic "vertical" look, but the branch chopped off this vertical trunk. It has been 2 years since that happened and the tree is still green and growing, but it is only growing horizontally now. It is currently about 4 feet tall, and the main trunk is about 8 inches in circumference at the base. So: 1. There is a bit of dead branch still at the top of the tree. Do I cut this off until I reach living tree? and does this make the tree more likely to get diseased? 2. Will this tree ever fruit, or has this permanently stunted its growth pattern? And is there anything I can do to reverse this? 3. Should I fertilize, and with what? The top soil is fairly dark and seems rich, but about a foot or so down the soil is mixed with a good bit of sandy-ness. I put some vermiculite in when I planted it, and there is still some floating around in the soil. 4. It has never flowered. Is this normal? I also have a key lime tree about a year old and about 1-1.5 feet high. Should I fertilize this the same way as the grapefruit? Thanks for any help on this. It was quite a wonderful tasting grapefruit and I hope that it will produce similar fruit.
The grapfruit is the slowest of all citrus to produce fruit from seed--it will take up to 15 to 20 years. There is a shortcut--you can graft some mature wood (wood from a grapfruit tree that is already producing fruit) and it will fruit within a year or 2 (on growth from that mature wood). Citrus are heavy feeders and use fertilizer in the ratio of 5-1-3 NPK. A mature tree will use up to 1.5 pounds of actual N per year (that would be the amount of N in 15 pounds of 10-10-10). A 2 yr old tree from seed (inground) should get about a cup of 6-6-6 or 8-8-8every month from Feb to Sept. Container trees are fertilized according to the size of the container. Your key lime is one of the fastest to produce fruit from seed--just 2-3 years. It should be fertilized like the grapfruit.