Rototilling Weeds

Here is a question sent to me in June 2009 about rototilling weeds.

Question:
We're starting to get serious about landscaping our backyard. Time and money have been the main reasons we've been unable to since we moved in. Since we've moved in, the area has been taken over by weeds. I tried to work on removing them, but it's turning out to be a lot of back breaking work!!! I went to home depot and they notified me that rototilling it would be my best bet. but they mentioned to rototill the area, and then leave whatever's been tilled there, including the weeds. I understand that this will turn into a good compost for the ground? If we have plans to eventually lay out patio blocks for a sitting area, should I keep the tillings there still? And for the areas that we'd like to just have rocks, or maybe bark, should we also leave them there? As you can tell, I'm pretty novice to this, so any advice would be greatly appreciated.

Answer:
It may take a while for you to control your weeds. You need to remove the roots from the area you have rototilled. Many weeds can regenerate from just a small piece of root. If the weeds have set & dispersed seeds, which they probably have, you will have many new weeds growing in the area. Rototilling will not destroy weed seeds, it will merely move them around. You will have to pull weeds, by 1 means or another, for 6 months or a year. Weeds do not make good compost because they are full of seeds.

If you lay out blocks for a patio, you will likely have weeds growing in the cracks. These will come both from seeds remaining from the rototilling & from new seeds blowing in from the surrounding area. Rototilled ground is loose & will settle. It is much better to lay paving materials on hard-packed earth. Otherwise, your blocks will sink over time, settling unevenly. It would be better to scrape off the top layer of soil with the weeds in it, or pull the weeds. If you have particularly pernicious weeds in your yard, like blackberry, don't pave over them. They have deep & extensive roots. They will definitely come up through the paving.

I'm sorry to tell you that weeding is forever, even in areas with bark or rocks, although bark does help for awhile. The best defense against weeds is to plant shrubs & groundcovers. Most weed seeds will not sprout on densely shaded ground.