landscape fabric mulch?
I have been using heavy duty landscape fabric (not box store) (w/ grip irrigation) for mulch (after a few years of cardboard and wood chips) and so far it has been great. It allows the fruit and lower leaves to stay off the soil and dry fast decreasing mold and disease. It,s much easier to pull back when I need to add amendments. I have a concern that since it is black it will increase the ground temp on the hottest days, yet it hold moisture better which keeps it cool. I have also allowed some volunteer melons to grow as more of a ground cover for the area where i grow spring and fall crops.figuring the summer crops will keep the area they are growing in shaded and cool. I am also worried that it will cook worms and microbes. Will it destroy them or will they just go deeper? Are there any other concerns with this type of mulch?
Hi- the landscape fabric will increase soil temperature compared to soil covered with organic mulches, but we don't think the increase is significant. And the benefits clearly outweigh the negatives which could include transient disruption of soil organism populations as they adapt to the environmental changes created by the weed barrier. You are not cooking worms and can test that by digging down and examining the top 8 inches of soil. Robust plant growth and high yields would indicate healthy soil microbe populations around the root system.
The duration and intensity of sunlight striking the fabric will be influenced by garden location (southern exposure with strong afternoon sun will be hotter), crop positions within the garden, and plant cover (increasing the plant canopy will decrease and moderate soil temperatures). Sprawling crops like watermelon, winter squash, and sweet potato will reduce the amount of visible black fabric.