I really don't like using landscape cloth. And I am going to show you why.
Many times once landscape mulch is installed it is covered with bark mulch. Then that mulch is never removed and more mulch is added to it. The mulch decomposes into beautiful compost which is a good thing. However, it stays on top of the landscape cloth. So then the roots of the plants start growing above the cloth into the lovely, rich compost as you can see in the picture below.
The next issue I have with landscape cloth is that many times it is not properly installed. The landscaper or gardener will just cut a hole big enough for the plant, forgetting that the plant will grow. It is what plants do. So then the plant isn't getting enough moisture to the roots and so the roots start growing above the landscape cloth into the rich compost caused by decomposing mulch.
Here you can see the landscape cloth and the dark compost that has been created by the decomposing mulch and how it stays on top of the landscape cloth.
Now, a lot of times someone comes along and wants to add a plant to their garden that has landscape cloth. For whatever reason, they don't cut a hole in the landscape cloth they just plant the plant in the mulch, which is what happened above. You can also see what happens to the soil underneath the landscape cloth.
Here is a better picture of just what happens to the soil underneath the landscape cloth. There is a severe interface. What water does come through the landscape cloth just forms a solid layer of clay. Nature has provided us with a great system for amending the soil. We can add organic matter when we prepare our garden beds. We can then top dress with mulch which, as we have seen, decomposes into compost. That compost is full of microbes and other decomposers that are beneficial to the soil and the life of your plants. Earthworms move in and start areating the soil and moving the composted mulch down into your soil. Your soil improves, the plants are happy and you didn't have to do a whole lot of work.
Putting down landscape cloth stops that whole cycle. The nutrients from the composted mulch do not go into the earth. The microbes stay on top of the mulch and what forms below is a very distinct interface. None of these things are good for plants.
In case you missed it in the last picture, here is another look at that interface caused by the landscape cloth.
Landscape cloth also doesn't work for me because I know some of my plants are going to grow, they will need to be moved or divided and I am going to have to compromise the landscape cloth by digging additional holes in it or leaving a hole where the plant was. I also am going to want to add plants and that means making more holes in the landscape cloth.
Landscape cloth may do a good job of keeping down the weeds but the same things that keep your weeds down are also going to hinder your plants and soil. Some weeds, such as bind weed, just laugh at landscape cloth. They will grow to where there is a hole in your landscape cloth and then come up there.
Weeds are not desirable but they are not necessarily the awful evil we think they are. You should be able hand weed your garden beds and that areates the soil. Some weeds are also nitrogen fixers, which means they will bring nitrogen into the soil, a very good thing. A little hand-weeding for the health of my soil is not a lot to ask.
If you install your irrigation system below the landscape cloth, any time that you have a leak or other issue you will need to cut through the landscape cloth and either replace it or patch it. If you install your irrigation system above the landscape cloth moisture will collect in your mulch. That can encourage weed growth as well as decomposition of your organic mulch.
I understand that landscape cloth is recommended for xeric gardens. If you are using a rock mulch it may be ok. You won't be composting the organic mulch on top of your landscape cloth. The weeds that grow in the rock mulch (yes, they will grow in the rock mulch) will need to be pulled. And you need to remember that your plants will grow laterally so you need to maintain your landscape cloth every year, widen it around your plants. Also, you need to remember to move your drip emitters out as your plants grow or they will grow around the emitter. This causes problems because the roots will eventually rot from the water going into the middle of the plant. It will also cause maintenance problems with your irrigation. So if you use landscape cloth remember it needs maintenance like everything else in your garden.