Remove fabric. If it is certain that winter cold was in fact the problem, replace shrubs that are not hardy on your site with other kinds that will be. Mulch with wood chips instead of bark, compost or other powdery, crust-forming materials (like sawdust). I prefer cedar play chips to arborist wood chips. You can get the latter for free by making arrangements with an arborist that happens to be working nearby, but other stuff including weeds, garbage and foliage may be mixed in. I'd rather pay for the clean, aromatic and uniform cedar play chips.

When these are available.

 Bark mulch can be contaminated with salt or weed seeds
 Bark naturally contains waxes that prevent absorption and release of water in landscapes
 Sawdust is too fine a material to use as a landscape mulch and will prevent water and gas movement as
it compacts
 Softwood bark mulches are often not "gardener friendly" due to the presence of tiny, sharp fibers
 Arborist wood chips can be finely chipped if this is more aesthetically desirable

Here is a link that might be useful: The Myth of Pretty Mulch

Despite various opinions to the contrary, ANY kind of organic mulch will help the situation, some better than others. I personally prefer using compost for this purpose because A) it has a better visual aesthetic for my purposes; B) it offers faster and more complete nutrient delivery than most other choices; and C) there are no problems associated with the compost becoming incorporated into the soil, either intentionally or accidentally. The same cannot be said of wood-based mulches. I've never found compost to form a crust or be water repelling in any sense and it has a greater water retentive ability than most chip-type mulches. It does make a much more accommodating seed bed for weed seeds that may blow in however, even if it does work well to suppress existing weed seeds. Compost is not as long lasting as wood-based mulches and that can be a plus or a minus, depending on how you look at it. Since I like a 'freshly applied' look, I generally apply twice a year.

2-3 inches is generally considered adequate for any mulch type and this is often reduced for certain shallowly rooted plants that prefer a freer oxygen exchange. Avoid piling up around trunks or woody stems. Reapplying the same amount with each application may not be necessary - apply only enough to achieve the intended depth. No dispute on removing the landscape fabric -- it seldom achieves the desired intent very successfully and it is a PITA to work around....or through :-)

Hardiness of various plants is highly variable depending on their specific location, exposure and general well-being before entering the winter months. Ensuring they are unstressed and in the best health manageable before encountering cold weather will certainly improve their chances coming out on the other side of the season in good condition. I would not necessarily recommend one pull and replace all plants that suffered damage this past winter unless they are indeed dead. Often, winter cold damage is limited to only foliar issues and tip dieback that can successfully be addressed by some careful pruning.

Thank you both so much! Your various opinions confirm just what I'd been thinking, LOL. I want compost because the neglected soil is in dire need of humus and I wish to provide it as a topdressing that I can hoe in when I cultivate; I want bark because I want a material that will hold its structure without compacting especially if I truck in enough to smother weeds and insulate the ground. Maybe I should do both but I suspect that two delivery truckloads would get pricey, and I'm under the impression the nursery can't mix and match a truckload. Hm.

As for the damaged shrubs, it was probably drought stress combined with an unusual winter here on the Puget Sound. My MIL's 16 year old rosemary that had overwintered in place all that time bit the dust last winter, so it doesn't surprise me that the unwatered Ceanothus in my front yard had no chance. (The house was unoccupied from September 08 to July 09, and we suspect that the previous owners hadn't weeded nor watered for two years prior to moving out.) A lilac and a few coppiced twiggy shrubs were also casualties, and some roses and a young tree are slowly recovering while a couple of rhodies and roses are too far gone and some buddleia are straggly and unthrifty. I've been working at trimming off the damage, and one of four Ceanothus is coming back fairly nicely (another is leafing out but had more damage than good branches, and two never showed signs of life.) As I build the new garden from the bones of the old, I will definitely try to choose hardier shrubs and place them in more amenable microclimates, but for now I don't mind babying the still-tender ones through the winter as best I can until I decide what to do with them.

Well, thanks again, you've given me excellent fodder! :D

Wood chips decompose and enter the soil same as any other kind of organic debris. If wood on the ground had adverse effects on soil systems here our forests could not function.

Do not do maintenance cultivation around woody plants, it damages their roots. It is also detrimental to soil texture to repeatedly agitate the particles. One technique that has been advocated for controlling moisture loss from bare beds is called "dust mulching" - wherein pulverizing the surface layer with repeated hoeing causes water in the soil below to be retained - because you have destroyed the texture of the surface layer and made it dust-like and different from the rest of the soil.

Most kinds of ceanothus and rosemary are tender. For better results plant specific selections of known superior hardiness - in suitable hot and sunny exposures on well-drained soil, not watered after establishment.

Wood chips decompose and enter the soil same as any other kind of organic debris. If wood on the ground had adverse effects on soil systems here our forests could not function.

Again, ANY organic mulch will eventually decompose and add to soil texture and nutrient levels but wood-based mulches do so at a much slower rate than do leafier, greener mulches comprised of things like grass clippings or shredded leaves. The lignens and cellulose that give wood mulches their long-lived characteristics are much slower to be broken down and digested by soil organisms. Compost or composted manure, because it is much further along this organic process than even the leafier mulches, will contribute to soil quality and fertility sooner.

Wood on the ground is not an issue -- it is wood that may become incorporated into the soil that is of concern. Any kind of cultivation, whether it be for weed removal or replanting or new planting, offers the possibility of mixing the wood product with the soil. Unless you rake it away and reapply once finished with your chores.

What it all comes down to is a personal choice and your priorities of what you want your mulch to do for your garden. Any organic mulch is better than no mulch and they all work quite similarly to protect the soil and suppress weeds. It's when you get into appearances and specific tasks you intend the mulch to achieve that differences become more pronounced.

I am really glad I asked these questions because this discussion has been illuminating. :)

bboy, I'm thinking this is the crux of the issue: either we cultivate the top layers of soil to dry it, keep weeds down, and conserve moisture deeper thanks to the lack of capillarity to the surface, or we mulch deeply with a fairly permanent layer of woody matter that conserves moisture near the surface of the soil but perhaps is more difficult to weed and might not have the deep reserves of water for the summer droughts. The shallow-rooted woody shrubs like rhodies probably prefer the latter approach, huh. And as my soil seems fairly sandy, perhaps it's the surface water I need to focus on conserving. Must ponder this. :)

I am thinking that for now, since I need about a yard of compost anyway for my vegetable garden (my current priority) I will also purchase enough compost to amend all the existing beds with 1/2" or so (and remove the landscape fabric). Then I'll consider a delivery of play chips, or find an arborist with chips, for a deeper mulch where I want to conserve moisture next spring. The beds currently need a lot of work, there will be tons of weeding and moving plants and adding plants over the next year, so now is maybe not the time for extensive (and expensive!) long-lasting mulches...

Wood chips delivered by an Arborist usually has a lot of green leaves or needles mixed in with it depending on the variety of tree, or trees, and time of year if it's deciduous.
If the pile with a lot of green matter is allowed to set awhile it will begin mold. Spreading the chips then is not advised in my experience. I've been coughing for two days because I did it. I knew better too, but I just couldn't wait. I tried a filter mask, but couldn't breathe enough to work at an acceptable rate. I will have to wait until the mold subsides to continue with that pile. At least I got the part that was on the lawn. I'll work the older piles for the next few weeks.
Tilling in a leafy pile of chips does rob some nitrogen from the soil, but later it gives it back. You can add a high nitrogen fertilizer prior to tilling to compensate for the time delay. Adding fertilizer to a compost pile speeds things up also, and you have the added benefit of a hotter pile for killing seeds.
Wood chips make a nice mulch, but if you are concerned about it's appearance, you can always put a thin layer of bark over the wood chips. Look at the money you will save!

Depending on your qualifications for looks and functionality - I have had wonderful results with covering large areas in my new house that were weed gardens with first a few layers of newspaper, and then a thick mat of straw. for very rough weeds like blackberry or a grassy area, try cardboard, then newspaper, then straw. Cardboard is free in recycling containier at the back of any grocery store, newspaper also, and straw is about $7 per bale currently. Although, you have to be able to see the mattet wet straw all winter :) But i suppose you could cover with a light layer of wood mulch for asthetics....