Question... what are you wanting to add compost?

Adding compost to the top of the mulch will take away from the manicured look you have now. It would also accelerate the decomposition of the existing mulch to some extent.

In regards to pulling back the mulch... adding compost .. and then putting the mulch back. That's going to require a ton of labor that is only going to help the plants marginally. I would just let the existing mulch decompose over the next few years and benefit your soil that way. You could always add compost right before you apply a new layer of mulch later on. The foundation plants should be able to do well living in the native soil with the mulch on top.

I prefer to mulch with just compost and would go ahead and spread it over the existing mulch. You get just as good a manicured appearance (better than bark mulch, IMO) plus it is much more nutrient rich than a wood based mulch. I'd also question the notion that compost is only going to help the plants 'marginally'. Compost spread as a mulch is a huge boost to most plants.

Using compost as a mulch also means you may never have to apply any other fertilizer/nutrient supplement.

I agree with gardengal. Add the compost. It will benefit your plants greatly.

I suppose it matters what you have as compost in the first place. So... Jrupjr.... what kind of compost do you have available? You could spread some out under/around a few bushes/trees and see how you like the look of it after it gets watered in a bit.

My original response is based on my own compost. The compost that I ruff screen out of my bins looks like worm castings with bits of partially processed plant trimmings... kitchen bits... twigs... and misc stuff. I just use it on the veggie beds. Yes it is better then shredded bark nutrition wise... but after a handful of rains I wouldn't put it on par visually with any shredded bark mulch or as I use for my perennial beds.... shredded leaf mulch. It will only help "marginally" if you only have enough to apply it once across everything. So I would think weighing the input vs benefit is applicable in this situation... Even if it's purely a visual thing.

You can spread that compost right over the mulch without raking the mulch away.

How much mulch to apply depends, in grass usually you spread about 1/4 inch (prevents smothering the grass) while places with no grass you could probably spread as much as 1/2 inch.

kimmq is kimmsr