Hi Banana. Unless it's grafted, a seedling will take anywhere from 7-14 years to fruit.
A few people here on Gw said their seedlings produced fruit 4 years from germination, but it's rare.
It's a great experiment, and one never knows. Good luck, Toni

hey bananafan :)

from what i understand, they have a juvenile period of around seven years (i think!) so it might not fruit or flower for that long. several factors contribute toward this. heat/light/watering/fertilizer.

what kind of conditions is your current tree in? how much light? indoors/outdoors? if in a pot, how root-bound is it? how often do you water/fertilize? improved light can help it grow faster if it is lacking, and they are very greedy so fertilizing properly could be of benefit.

if you are like me, you will plant the seed and grow it for the love of growing. i have a few lemons/grapefruits/mandarins on the way at the moment - i have a looooong wait for fruit but i dont mind, i like the growing :) and when you do get fruit it will feel like such an accomplishment, even if it doesnt taste as good as the parent plant (though i believe most citrus are true to type)

any more info on the seedling? like light, water etc? once it has set its first true set of leaves (not the first leaves that pop up, theyre from the embryo - but the second set) you can fertilize with a weak, half strength fertilizer to get it going, and introduce it slowly to plenty of good light!

good luck. hope to hear more about your plants :)

dan

The lack of vigor can often be traced back to what's going on below the soil. Does the container or site drain rapidly after being drenched? Is the soil porous and well-aerated rather than mucky? If planted in situ, was it positioned too deeply? Did you incorporate a great deal of organic matter (like peat moss) into the planting hole along with the native soil?

If container grown, what is the potting medium like?

and of course, putting organic amendments in the planting hole or mixed in with the back fill soil is NOT recommended. Keep all organic amendments on the surface as a mulch.
and Kaffir lime leaves are the main reason the tree is grown, not the fruit. Try putting one or 2 whole fresh leaves in your next chicken soup. MMMM yum. Use them like whole bay leaves. Choose leaves that are full grown but still young and fresh. The leaves are used in many Thai recipes.
I'm told the Thai women use the juice of the fruit as a hair rince.