Mulching vs Composting

I've been mulching beds each year with hard bark shredded mulch. I have lots of acid loving shrubs, and perennial beds. I think that composting might be better for my soil but don't know enough. Do I need to add compost to my beds or is mulching with hard bark enough? Should I change the kind of mulch I use? Will compost keep weeds out like the hard bark mulch or just improve the soil? Do I need both compost and hard bark mulch in my beds? Can I add compost any time? Is there a special time of year to add compost? Take pity on this novice gardener........

Hi D
On the whole, mulches should not be considered a soil or plant food. Most of them release some nutrients as they decompose, but the food value is very small. Where mulches are needed, use them for the mulch value (weed control and water retention) and add fertilizer as a supplement.
Compost usually mixed into the soil, is made up of decomposed organic matter that has trace nutrients in it. It will improve the texture and health of the soil.

Hi....this isn't really a reply, but a related question. I'm in zone 5a and it's hot here in Illinois. After fertilizing, I'm getting lots of weeds and I'm worried about retaining moisture. So I should mulch, yes? But I don't understand how water gets through a couple inches of mulch (I buy organic cypress mulch). Instead, could I put a couple inches of compost (bags of composted manure and mushroom compost) on top of the soil to keep out weeds and keep moisture in?

What dovey said!

Otto, compost is a type of soil. Weed seeds will readily grow in it. Mulch is what you're after. And not to worry about water finding it's way though.

Otto,
I think it's pretty tough to over compost your soil, it's something most people fail to do often enough, add it under your mulch if you like.
When you spread a nice think layer of compost you will notice after a few months it's thin and slowly disappearing.
That's because the soil is digesting the compost, a beautiful thing.

Using organic cypress mulch sounds great, after I spread mulch I water it well, from then on your normal watering should be fine. The mulch will prevent the sun from evaporating the water in the 1st few inches of soil where most of your plant's feeder roots are.

Mystery solved---thank you, thank you, thank you!

Another beginner's question, please? I have a row of big, old, overgrown spirea that I cut back after they bloomed this spring. But what would happen if I cut them way down---say, to 10-12" of the main branches? Would I get filled-out chubby shrubs?

I always prune with a desired shape in mind, I never just whack anything back.
Spirea can be severely pruned and if you want a chubby shrub then cut it back.

Thanks, Dovey. I think I misspoke---I don't want a rounded, compact shrub---what I like about this kind of spirea (bride's veil) is its random, arching nature. It's just that I think something drastic needs to be done at this point.

Ah, if I wanted to maintain the arching nature I would select the strongest trunk like branches and trim off all the lower branches, leave the top in tact.
That will maintain the large weeping appearance, basically what I would go for is a clear multi-trunk shrub that flowers on the top.

If that's not what you had in mind, it's a good idea to just clean things up and remove old, broken and unhealthy branches... thin it out and freshen it up.

There is a False Spirea called bride's veil - Astilbe a. 'Bridal Veil'
http://www.horsfordnursery.com/new/plants/perennials/images_big/big_Astilbe_Bridal_Veil.jpg

Or do you have spirea Bridal Wreath
http://www.donnan.com/images/SpireaBridalWreath.jpg

Perfect, Dovey, I'll follow your first suggestion---and I like the lingo--"weeping." Thanks, so much, too, for the links. I have spirea Bridal Wreath.

It sounds beautiful
Cheers
Dove

Thanks Dovey. You nailed it in your reply. One more questions though, do you spread the compost all year long or is there a time to do this? I imagine I just pull back the mulch and through down a layer of compost and then put back the mulch.

DW
Mulch (and compost) has a way of disappearing and I doubt you will have to pull it back to apply compost.
If your mulch is in tact then by all means pull it back in the spring after the weather warms up and apply it.
Then do it again in the fall before the weather gets too cool.

Paul James (Gardening By The Yard) says applying a thick layer of compost & mulch too early in the spring can slow down the spring growth by keeping the soil too cool.
He says it's best to wait until the ground warms up a bit before spring mulching.
Mulching No-Nos
http://www.hgtv.com/hgtv/gl_soil_water_mulch/article/0,1785,HGTV_3634_2165885,00.html

Thanks Dovey once again. I've started adding some compost to one of my perennial beds to see their reaction. I figured since I needed to replace some mulch, why not throw down some compost? I