The newspaper will prevent any grass and weed seeds from germinating, but unlike fabric, it will decompose after about 18 months. By that time, any grass and weed seeds that were present in the soil on planting will be dead. It’s green, it’s cheaper than fabric, and when you decide to remove or redesign the bed later on, you will not have the headache you would with fabric.
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Easy Method to Create a New Flower Bed - Takes almost 2 months for the bed to be ready for planting. 1) Mow area & reduce weeds. 2) Lay newspapers about 2 cm thick and wet through. 3) Lay some blood meal (helps decomposition). 4) Lay about 4 cm composted manure. 5) Lay 5-7 cm mulch. 6) Keep bed moist for 45 days to 2 mos. 7) After 45 days, dig a small hole to see if the newspaper has composted and if the weeds underneath have gone down. If so, then bed is ready for planting. This is a good link with pictures.
Southeast Seed Bombs - Bird Bee and Butterfly Friendly DIY Guerilla Gardening Seeds Seed Balls. $7.00, via Etsy.