Digging things and preventing them from returning

Asked October 16, 2013, 7:14 PM EDT

I'm in the process of tearing up my front yard. I dug up the front lawn several years ago and planted ground cover (woolly thyme, etc) to help cut down on the maintenance. The yard was fine for a while, but it's now desperately in need of help. I have a patch of oregano that will not go away (this is not the first time I've dug it up), and I also have patches of grass that appear. The ground cover is dying in spots, but still healthy in others, and I have low growing weeds and clover that are fighting for attention. I want to dig everything up and start with a clean slate again. My goal is to basically have bark dust/mulch and some grasses/NW friendly plants. Something easy to care for and visually friendly. Somebody suggested that I lay down a special plastic on the ground for a few weeks, once I dig up the grass, to make sure the roots to everything that was there (the grass, oregano, weeds, etc.) die. Is that the best route to take? If so, what do you recommend? I'm not planning to plant anything until spring, but I'm also wondering if it will be okay to at least put down the bark dust once everything is dug up and/or dead so that I don't have a mud pit for a front yard this winter. Is that a bad idea? or, is there something else I should use? Thank you!

Multnomah County Oregon sustainable gardening and landscaping weed control thyme groundcovers

1 Response

Establishing a thriving groundcover can be challenging. The secret to success is continuous persistent in removing weeds as they develop in the blank spaces among the new plants. Woolly thyme does best in well-drained soil. It tolerates dry conditions in full sun to partial shade. But it won’t thrive in dense shade or wet conditions. It can also tolerate limited foot traffic – “limited” is critical to the thyme's survival. Sometimes a combination of several kinds of groundcover plants works well, with each kind in the appropriate site. Weed control is an absolute requirement until the groundcover is fully established, perhaps in the third year, and beyond. “Groundcovers” (Clemson University) is a thorough overview of how to establish such a planting - http://www.clemson.edu/extension/hgic/plants/landscape/groundcovers/hgic1100.html

Whatever your strategy for the area -- starting over or resolving the current problems while retaining the healthy portions of woolly thyme -- you should cover the bare soil. So, yes, bark dust or mulch will be suitable. Even so, you must always be aware that additional weeds will sprout and should be dispatched as soon as possible.


Weeds will survive if covered with plastic for only several weeks. To be successful, it must remain in place for several months.


It’s easier to get rid of some kinds of weeds than others:
- Annual weeds (these grow for only one season) can be removed by hand or hoe, hoed out while less than 2 inches tall. Or simply cover with a 2-inch deep mulch.

- Perennial weeds (such as dandelion, bindweed, horsetail and your oregano) will require 3 or so years of active effort. Remove the green growth either every week or as soon as you see it, then repeat. At the same time, watch for seedlings of the same plants. (My oregano spreads by spreading rootstocks and also seeds profusely; it’s coming out in a week or two but I'll need to remove seedlings for years.)

- Never allow any weed to flower and set seed.

Thank you for using Ask an Expert,
Jean