Hi JorgNS,
Generally, most varieties of apples will need a pollinator, which could be even
a flowering crab apple in your neighbors yard. It is crucial that the blossom
times
of any such trees are close enough together, so that insects can carry the pollen
from one tree to another. Even with the 'self fruitful' apple varieties, you will
get
a much better crop, if there is a good pollinator nearby.
Also, a dwarf apple tree, planted from a 2-3 foot whip, should take about 5
years
before you get a decent crop. It might produce a handful of apples sooner, but it
is better to prune those off early to encourage better root and tree development.
I can't speak about avocado trees, as we don't grow them here in the Midwest,
but my remarks about apple trees should hold for your area, as well.

Sherwin D.

JorgNS wrote:

I recently had a couple of hedges lining my driveway removed and I'm thinking
of planting a dwarf apple and a dwarf avocado tree. Anyone in the Southern
Calif. area have much success with either of these trees? I'm wondering how
long it would take for the trees to fruit & would I need to plant more than one
for them to fruit?