Shredded native tree trimmings.
Shredded hardwood bark.
Mulching should be done after planting is completed. Acceptable mulches include shredded hardwood bark, pine needles, coarse compost, pecan shells, and shredded cypress bark. Shredded native cedar is the best of all. Mulch should be at least 2” deep on top of planting beds, and deeper around larger plants. Mulching helps hold moisture in the beds, controls weeds, and buffers soil temperature. It also enriches the soil as it decomposes.
Do not use plastic sheets or weed blocking material. These artificial materials provide nothing beneficial. Plant’s roots system can cook from the heat buildup. Plastic also cuts off the oxygen needed by the soil. I also do not recommend fabrics or gravel as mulches. Nothing compares to a thick layer of shredded organic material. Lava gravel is the only possible exception. It works almost as well and helps to keep the neighborhood cats out of the beds.
The best mulch for any site anywhere is recycled plant material (leaves, twigs, spent plants, buds, bark, flowers and other plant debris) that grew on your property. That's the natural way it is done in the forest and on the prairie.
The second best choice is purchased shredded native cedar.
Third in line is shredded hardwood bark.
Then there is a group in the middle that includes cypress which is not high on my list because it does not break down well.
We want the mulch to break down. That's what creates the true natural food for feeding microbes and plant roots.
Pine needles make a good mulch but look a little out of place when used on a property where no pines are growing. Lava gravel makes a good mulch and has the extra benefit of keeping squirrels and cats out. Looking more harsh than organic mulches and not breaking down into humus are the negative points. I'm not at all a fan of shredded rubber products, dyed wood or pine bark. It's interesting that the most popular mulch material, pine bark, is not very good. First, it won't stay in place - it washes and blows away. What does stay breaks down into a mucky material that does help plant growth.
Nature doesn't allow bare soil and neither should we. For shrubs, trees and ground covers, use at least 1" of compost and 3" of shredded native tree trimmings or shredded hardwood bark. Mulch vegetable gardens with 8" of partially completed compost or alfalfa hay. Mulch preserves moisture, eliminates weeds and keeps the soil surface cooler which benefits earthworms, microorganisms and plant roots.
Question: Are all cedar mulches created equal? The main thing I want to do is repel roaches and other bugs from around my foundation. L.M., Dallas
Answer: The fresher the better with cedar mulch. All cedar trees make excellent mulch, but I prefer mulch made from our native cedars. Freshly cut cedar mulch has more oil in the wood, which provides fragrance and repels insects. Repelling insects is a nice side benefit, but the primary purposes of mulch are to protect the soil and help build humus.