Jim Carr wrote:

I got one of those key lime trees as a gift. It's in a small planter. The
instructions say to prune it to make it bushier if I want. However, I don't
know what to prune. It's about 9 inches tall. There is one branch going off
the side. There are leaves all the way up the "Y" split.

Should I trim back the tall part? If so, how much? If not, then when do I
prune and where?

Much obliged for the feedback.

A plant that size should not be pruned. You may pinch out the tips
of the branches to make them bushy. However, I would wait until it
is about 2 feet tall.

In the meantime, you should consider repotting it into a large
container. Even dwarf citrus should be in containers at least 16
inches in diameter and equally deep.

See my http://www.rossde.com/garden/dwarf_citrus.html.

--
David E. Ross
Climate: California Mediterranean
Sunset Zone: 21 -- interior Santa Monica Mountains with some ocean
influence (USDA 10a, very close to Sunset Zone 19)
Gardening pages at http://www.rossde.com/garden/