Everyone has their favorite, depending on location and availability. I prefer to mulch with compost and avoid needing to fertilize with anything else.

We have a source of moderately well composted mixed wood chips that Robert and I keep secret from ALL! It's black, yet coarse enough to last for months. That stuff would be my favorite.

There's also an arborist in town who has a different kind of chipper. Something really different comes out of that machine! His finished product is quite pretty and always welcome in my yard.

Both are free for the taking.

I use shredded leaves, wood chips, pine needles and I don't use any mulch specific for any plant. Pine and Oak though once thought to make the soil scidic do not but the addition of any organic matter will buffer your soils pH some so that pH will not be as large a criteria for those plants that "need" and acid soil.

I have read recently, in several publications that I believe to be creditable (although they may all be sourcing the same study), that the newest finding is that flowers, whether annuals or perennials, and vegetables don't do well when mulched with pine straw. They do much better with any other organic mulch, wood or compost or straw, etc. However, pine straw does very well as a mulch for trees and shrubs. It also seems that pine straw does less than people had thought to keep soil acid - it is nearly neutral in its effects. Just a nugget of possibly new information, for what it is worth.

As for the mulch I use, for flowers, trees and shrubs, I use double-ground, aged wood mulch. For the vegetable garden, I use compost and wheat, oat or barley straw, whichever the local farmer I purchase it from has cheapest.

Thanks for everyone's input. I think I will check out the Farm store for some straw like you mention, Dibbit. I will continue using my Holly Tone (espoma), on the acid-loving plants, because our soil in Oklahoma is very alkaline.

Will also use my own compost to top off plants before adding mulch. Mulch is pretty necessary in Oklahoma because of our summer heat. Last year we had 100+ temps for 2 months. I use soaker hoses that I cover with mulch, but without the mulch, it wouldn't do much good. The trees surrounding the property soak up a lot of the water as well as the heat.

Susan

I have gardened in Texas in the hard black clay for 16 years now, and the best mulch which doubles in keeping your soil from hardening is the small Pebble river rock. I till it in and as I water, the rock makes it way to the surface and acts as a mulch and holds water in.
I would NOT use pine needles, or pine bark mulch! Think of what it looks like under pine trees, nothing grows, right? It changes and depletes your soil!

Marcie, the OP asked about organic mulches, which I took to mean those of vegetable origin. While river, and other, rocks do work as a mulch, they only open up the soil structure if tilled in, as you have done and add nothing to the organic matter in the soil. While I would, and have, used rocks for those plants which NEED good drainage around their crowns (Lavender, rosemary, etc.) the continuing rotting/breakdown of the 'organic' mulches adds more nutrients to the soil, breaks up clay, adds to the soil structure, adds humic acids, etc., etc. It is part of an ongoing process in improving the soil, while the rocks would be a one-time 'improvement' which did not continue to improve the soil.

The lack of other things growing under large pine trees has more to do with a lack of sun and the dryness from major root competition than from the pine needles, bark or straw "changing" or "depleting the soil". Both pine straw and pine bark are slow to break down, but they do eventually break down and add organic matter and all its benefits to the soil. Wood chips, aged, do break down faster, and are better to use on flowers and vegetables.

Among the reasons I use mulch is to keep moisture in the soil (I have red clay), and keep it from turning to 'rock' when it's hot and dry, but I also use it to limit weeds, to add organic matter to the soil, and to generally improve the soil.

No organic mulch of any kind will "deplete" soil. And the changes it will make are uniformly good. 'Mulch' implies a topdressing, not an amendment incorporated into the soil. One does run a risk of temporary nitrogen depletion when incorporating woody-based mulches into the soil but their effect on the soil surface when applied as a topdressing is minimal. Ditto with any acidic considerations from conifer needles or oak leaves.

As any organic mulch gradually breaks down and decomposes, it releases nutrients into the existing soil and helps to improve soil structure. It also encourages populations of beneficial soil organisms. No inorganic mulch can offer these qualities although many can be quite effective in moderating soil temperatures, providing weed supression and conserving soil moisture.

The studies that indicate mulches are harmful to plants are usually made on soils so devoid of organic matter that the mulch is the only thing the Soil Food Web has to munch on, and that is guaranteed to produce poor plant growth. Because of the growth in organic gardening the companies that sell the poisons are becoming more interested in proving that organic gardening does not work and will try many methods to get there. Be very careful of what a writer is saying and trying to prove.