Does one Paper Weed Barrier Block Fertilizer?
Old newspaper, kraft cardboard and paper make excellent mulches, allowing water and nutrients into the dirt while keeping sunlight away from germinating weed seeds. This works best around established plants; it can keep flower seeds from germinating enjoy the grass seeds. It is ideal to fertilize before inserting the paper, but some fertilizers still work once you install the paper.
Stick to Liquid
After installing several layers of newspaper or other kinds of paper, then cover it with a heavier type of mulch, such as wood chips or stone, to keep it from flying away from the wind because it dissolves. Apply either granular or liquid fertilizer below the mulch — the paper allows water through to the dirt, so it helps transfer the fertilizer to the roots of your desired plants. After setup, however, stick to water-soluble or fluid ready-to-use fluid instead. A few of those granular fluid may soak through moist paper since the fluid softens and breaks down, but it is not quite as effective as using those already in fluid form.