Depends on how fast you want your hedge to grow in. I would plant 2' on center but podocarpus is a big tree that could easily span 6' o.c..

Also, be aware that many municipalities place the same limit on hedge height as they do wall height. So it's possible a tall hedge would be illegal. It is in Los Angeles but they only enforce the ordinance if someone complains.

I went and looked at my neighbor's hedge down the road. They are on 3' centers. It makes a beautiful hedge, if you are good about regular trimming.

{{gwi:547624}}

Thanks for the info.

What do you think about the spacing for the purple hopseed bush I want to use for the back wall sections, privacy is not an issue there, just needs to look good?

As for the citrus trees, the normal sized trees seemed too big, thats why I am considering the dwarf versions, what do you think, one or two per center planters?

Depending on which citrus you choose, a dwarf can get 10-20' tall and nearly as wide, even on true dwarf stock. One per planter.

I grew Purple hopseed for 10 years, not a fan. It's a short-lived small tree, looks good and grows fast for about the first three, then declines rapidly. Whole branches simply die off. Also reseeds like crazy, though the seedlings are very easy to pull. 10' centers. It's great if you want something for about 5 years that you know you are going to be pulling out, but it is not a good plant for the long haul.

I know P.gracilor looks like a good hedge for a few years...but they want to get big later..and you end up trimming off all the weepy parts of the plants. Whats a better Podocarp for hedges and privacy screens in smaller areas is P.macrophylla. I've seen them kept forever in 3 x3 x 6-8 tall spaces per plant for as long a hedge as you want.
P.gracilor might not be a huge tree...but its determined to be plenty big.