For ornamental woodies, all that's needed is to maintain a mulch of compost on the soil surface.

Recall that fertilizer makes plants grow. With woodies that typically translates into lots of growth which must then be pruned off -- regularly.

If established woodies have 12-18" new growth each year, they're fine -- no fert needed.

Many shrubs grow only a few inches per year; a soil test will tell you if you need to add fertilizer.

Generally, it's better to use too little rather than too much. I use compost and bark mulch, that's about it. If ther's a problem, I might do a soil test and then add an organic fertilizer if anything is needed.

That's interesting. I'm more of a lawn person. I assumed that shrubs needed regular fertilization like the lawn does. No huh? Only if there's a problem?

You got it! FWIW, if you utilize a mulching mower, there is little need even to fertilize your lawn very frequently. And lawn fertilizers are some of the biggest polluters around, specially of groundwater and streams and rivers. We all tend to fall victim of fertlizer manufacturers' advertising hype. They would like you to think that you cannot possibly have a healthy and lush garden without the frequent use of fertilizers and it simply ain't so!

I fertilise roses. I fertilise fruit trees. Pretty much every other tree and shrub just gets compost whenever I have it available :)

I holly tone my rhodies.