Yes, it does decompose more quickly. It also uses a good deal of the available nitrogen as it biodegrades, sometimes usurping nitrogen from plant roots. If you are an organic person, blood meal is a good nitrogen replenishing source. Not organic? Urea, but go easy. Oh, and be ready to replenish the bark more quickly, too.
hortster

Is it better to just go with a mulch that has more shredds of wood vs. more bark?

How fast any type of mulch might be digested will depend on how active a Soil Food Web you have as well as the type of material presented to them. The smaller the particles are the faster they will be digested, so a fine shredded bark mulch could be digested much faster then a course lumpy wood chip mulch. When used as mulch no high carbon material, such as bark fines or wood chips, should cause the soil Nitrogen levels to be tied up in the digestion of that mulch, that digestion should be a relatively slow process compared to what tilling the same material into the soil would be. I have not seen soil N depletion in any beds that I have mulched to the contrary I have seen plants that I have mulched with high carbon material turn a deeper green and grow much better after mulching because the soil is now evenly moist and the soil bacteria are bette able to feed the plants what they need for proper growth.
Any vegetative material used for mulch will, eventually, supply organic matter to the soil as the Soil Food Webs works on and digests that material.

Ignoring such factors as looks, ability to work with, how long it lasts would one suggest a shredded hardwood that is higher in wood shredds or bark fines?

What I'm trying to get at, am I doing any favors for my plants by adding a mulch that is higher in bark fines?

Thanks!

The thing fine mulch does most is to add carbon to the soil food web. This grows the soil microbe numbers and normally drains the available nitrogen from what you are trying to grow.

Hardwood bark mulch is often high in calcium and if your subsoil or water have high alkalinity you are likely adding the wrong thing. If you have an acid soil or water you may do good using it. Is that what you have Kimmsr?

I try to use aged "native mulch" made from mixed ground twigs and branches which adds a a wide variety of nutrients. The nutrients reside in the cambium layer of the twigs.

In either case, try not to mix the mulch with the soil and watch your color indications of the leaves. If you mulch you should have healthy earthworm numbers and they will eat the mulch and till it into the soil at a rate the microbes can handle without causing great imbalances. Dont rush these natural cycles. Dont kill the worms with strong stuf. Feed them meal based organic fert in addition to the mulch.

whaas, yes, while there are pros and cons of the finer mulch, there ARE ways in which using it does your plants some good. Because it is degrading faster, it is moving from being "mulch" to being part of the soil faster than the mulch of larger woodier chunks would do. Degrading faster means you have to replenish it sooner, and means you have to watch out for whether there is enough nitrogen for your plants, but in the process, it is making the soil healthier - better structure, air permeability, nutrient holding capacity, stuff like that (it is doing this by adding organic matter and feeding the many and various beasties in the soil).

lcpw

Isn't most hardwood mulch aged native mulch? From what I can tell its just a mix of various trees and shrubs, anything from maples, to oaks, to pines.

I have an alkaline soil. I'd say most of my plants are fairly healthy with good color.

The only trees that seem to be a little off in regards to color (slight yellow) and aren't very full are Japanese Tree Lilac and Maackia amurensis. The color is good so far this year but both are still a little "thin". Both are on their 3rd year in the ground.

Both my River Birches (which are subject Chlorosis) have a good green color for the last 3 years in the ground.

Here is a link to mulch blowing...I wish I had one of those!

Couple things the guy mentions:
Larger wood chips pull nitrogen vs. bark fines
Only need 1" vs. 3"
Typically the lighter the mulch the worse off for your plants. For example the stuff I get with the bark fines is very dark.

Comments?

Here is a link that might be useful: Mulch Blowing

It is the size of the particles that help the Soil Food Web digest the mulches you lay on your soil. The smaller the particle the easier it is for the wee bacteria to work on it. Put a largeish particle on your soil and the bacteria will have a hard time working on that and it will last, seemingly forever, while a particle of dust will seem to "disappear" overnight.
My experience is that it matters not whether you have an alakaline or acidic soil or water. If you have an active Soil Food Web (a good, healthy soil) and the mulch particles are small then they will get digested fairly quickly while the larger particles will not.

If your looking for the mulch to last longer the smaller particals probablly aren't the best.

But ignoring that are the smaller particles better for the plants?

I just want to make sure I'm not applying this shredded hardwood with higher bark content going under the assumption that its better for the soil/plants.

If not I'd changed over to the stuff that has more shredds of wood.