The bark mulch kept the weeds out almost entirely which was wonderful but the tomatoes did not do very well. I had a massive foliage wilt and die-off on the bottom half of the plant before the tomatoes started to get fully red. I did get some tomatoes but not nearly as many as in previous years. I also noticed over the winter that the bark mulch was not decomposing very well. After Roy tilled I did not notice obvious residual bark chips which was good since I was worried about how will it would till in and compost, and how it would effect this years plants.
The straw and grass mulch did well. There were more weeds but I noticed that it composted much more easily over the winter and I am not concerned at all with the plants that will go in that section this season.
I looked into it a little and some sources say that shredded bark mulches should not be used in veggie gardens in the first place since they are not fully decomposed and steal nitrogen from the top layer of soil as they break down. They take several years to decompose and are acidic so I should have monitored the pH level of the soil. Some sources say that it is ok to use it, but from my experience, it caused trouble. This probably explains my tomato problem and I will not be using bark mulch in the veggie gardens again.
Bark mulch is for landscaping.
It is used as a decorative covering.
Using it around young seedlings and vegetable plants results in excess numbers of pillbugs, slugs, snails, etc. that can, when they have nothing else to eat, lead to plant damage.
It provides no nutrients to the plants, can rob nutrients from the plants, does not retain soil moisture nearly as well as many other mulches.
This year I am using a cardboard and straw/grass clippings method. I am putting down a layer of heavy cardboard and covering it with straw and grass clippings. This will be used in the walking rows between the plant rows, and the plant rows with only be about 6 inches wide. This will limit my weeding which saves me precious time and I will have no concerns about how this will compost into the soil for next season.
Updates to follow - I am sure that I will find both problems and benefits with this new experiment.