Help me reboot an old garden plot?

July 13, 2019 7:09 AM

A 16' x 20' garden plot has been overrun by weeds and invasive plants. I'd like to break it down and start from scratch. Best way to do that?

The weeds/plants that have taken over this plot are mugwort and mint; two notoriously difficult plants to eradicate. This is my plan so far:

1. Remove everything by hand as much as possible in an attempt to get the roots out.
2. Cover entire plot with newspaper.
3. Cover plot with a UV blocking tarp and let it sit there until next Spring.

Are there any steps I'm missing or other measures I can take? Particularly between steps 1 and 2, I want to stay away from chemical weed killers, but is there anything I can do to help ensure the invasives don't pop back up in 2020?

posted by jeremias to Home & Garden (6 answers total)

Yep, that's a good plan for minimizing labor and maximum effectiveness.
Liberal use of boiling water will help kill off small bits. If your tarp is fairly airtight, you may get some anaerobic rot going on under there which will stink but won't hurt anything. Cardboard will help more than newspaper, but use what you have. If it's brown on both sides it will compost in place well, and you can plant into holes you tear in it next spring, leveraging it as weed suppression for longer. Whatever you use, you should put a light layer of leaves or mulch or something over the tarp for better effectiveness.

Half a season isn't that long for herbaceous perennials; they are patient and hoard their resources underground. So don't be surprised if you get some survivors. Additionally small pesty seeds can live for hundreds of years in the seedbank, and some of them will see next spring as a good time to sprout due to your treatement. You may want to look into lasagna gardening or the related Hugelkultur. These low-disturbance methods will help you going forward, as most weeds thrive best when the garden is subjected to soil disturbance via tilling/plowing.
posted by SaltySalticid at 7:38 AM on July 13, 2019 [2 favorites]

The high disturbance method would be to rototill. The machine can be rented.
posted by SemiSalt at 8:00 AM on July 13, 2019 [1 favorite]

Have you considered using clear plastic to solarize the garden? I wonder if you could do that first, then put down cardboard and organic material over the winter?
posted by SandiBeech at 11:03 AM on July 13, 2019

Seconding lasagna gardening. I wouldn't till at all and wouldn't bother weeding. Gather a bunch of plain cardboard boxes, layer them over everything and soak through with a hose. If you want to garden this year, acquire/buy a bunch of garden soil and some mulch (I used to use straw as per Ruth Stout, who you should google, but we had too many slugs so now I use wood chips). Poke holes through the cardboard where you want to plant things. You might get some weeds come through but probably not many.
posted by PhoBWanKenobi at 11:51 AM on July 13, 2019 [6 favorites]

Also the way you address this next year is to continue to layer things on top of your soil. This is also called no work gardening, the Ruth Stout method, no dig, back to Eden . . . . they're all variations of the same thing. I'd highly, highly recommend Ruth Stout's ancient out of print book, The No Work Garden Book. It's funny and very down-to-earth and helped me see that what's important for my garden is not that it looks right but that I figure out what works for me and my space myself.
posted by PhoBWanKenobi at 11:56 AM on July 13, 2019 [1 favorite]

Mow the stuff. Then cover with cardboard, soil, mulch, and plant away. You will do great. I have had great success with this method. No tarp nneded,and in fact I found the tarp annoying, as it doesn't disintegrate and makes future planting difficult.

If you are really concerned about the vigorous perennials, you could hit them with Roundup, which doesn't affect the soil, as soil neutralizes it. Then let it work for a few days before covering the weeds with cardboard. But I know this is not PC.
posted by Enid Lareg at 8:04 PM on July 13, 2019