Digging a New Bed

March 19th, 2013

   It seems like it’s taking forever for winter weather go away this year, but sometime soon, the coast should be clear to get out there and start digging some new garden beds.

To dig or not to dig, that is the question.

    Or not. 

   What I mean is that not everybody agrees that the best way to dig a new bed is by digging a new bed. Huh?

   A lot of people like to take the short cut of killing off lawn with Roundup, planting right into the dead turf and then mulching the whole thing. Nearly instant result!

   Others are going the trendy no-till, no-spray route by laying cardboard, newspaper and/or mulch over the lawn to smother it, then planting into the decaying mix later. Once again, no digging… although this route requires more patience.

   Both of those can work fine, but this week I thought I’d share what I do.

   I prefer the old-school, dig-the-grass-by-hand method, followed by tilling in organic matter to create slightly raised beds.

   It’s definitely more work than the other options, but I try to avoid chemical use whenever possible and have had excellent results. I think it’s the best way to deal with the crappy “builder’s soil” that most people have in housing developments.

   Here’s the step-by-step:

   1.) Mark off the bed with rope and spray-paint along it. Then use an edging tool to cut a line around the perimeter.

Sod pieces, stripped by hand and rolled in manageable sizes.

   2.) Strip off the sod in foot-wide sections, using a shovel to get underneath and disconnect the roots. I roll them up in about 3-foot-long pieces (manageable size and weight to move). I use some of the sod pieces to patch thin or dead spots in the lawn. Or I compost them. Or I set them aside for later use on the bed. (More on that in a minute.)

   3.) Next, I use a tiller to loosen the existing “soil” to 10 or 12 inches deep. I go over it two or three times. Wait until the soil dries a bit if it’s wet. In small beds, I hand-dig with a digging fork.

   4.) Spread about 2 inches of compost, mushroom soil, rotted leaves, peat moss or a blend of any or all of those over the loosened planting bed.

   5.) Go over the bed twice again with the tiller to incorporate the organic matter into the existing “soil.” Rake smooth.

   6.) If I haven’t used the sod for patching or composting, I flip the pieces upside down over top of the prepared soil. These act as mulch and will break down in place. Sometimes I’ll use 6- to 8-page sections of wet newspaper in the same way. Then I top with 2 or 3 inches of bark mulch or wood chips and plant as I get around to it.

   Going the Roundup route is popular because it’s quick, easy and kills the grass so there’s no chance it’ll re-root. In decent soil, you could then plant right into the dead turf within days and mulch over top for a nearly instant conversion.

   Even if you’re tilling and adding compost, Roundup saves the step of having to strip off the turfgrass. It tills up easily when dead.

   The Scotts Co. says you can plant flowers, trees and shrubs in a Roundup-treated area just one day later, although it usually takes 2 to 4 days for treated plants to show signs up dying and 1 to 2 weeks for those plants to actually die.

   So from a practical standpoint, I’d suggest waiting 2 weeks to give the product a chance to work fully.

   I did a test myself once by planting new annual flowers just 3 days after spraying a weed patch with Roundup. Even though the weeds were barely showing signs of dieback, the flowers were unaffected and went on to grow normally as the weeds died back.

   Keep in mind that Roundup doesn’t work as well in cold weather as in warm weather when plants are actively growing. The product label says to apply it when temperatures are above 60 degrees for best results.

   Not everyone is comfortable using Roundup – or any chemical herbicide, for that matter. I don’t think it’s the deadly poison that some people make it out to be, but it’s not totally innocuous either. I lean to the cautious side and figure there’s no need to spray lawns with it so long as I’m able to dig instead.

   As for the smother-the-grass approach, the idea is to top the lawn with cardboard, newspaper and/or compost, then top that with about 3 inches of wood mulch, bark mulch or wood chips.

   That does away with spraying, turf-removal and tilling, but the main downside is that you should give the area about 6 months for the turf to die and begin breaking down before planting.

   I’ve seen good results and have heard positive feedback from people who have gone that route. I think it works best when the soil is reasonably good underneath.

   Some argue that it’s actually best to plant plants in native soil without altering/disturbing the soil texture and structure by tilling.

   I agree with that when the soil is even fairly decent. But given the horrid and heavily disturbed subsoil I usually see in people’s yards, I think it’s best to restore it by working wide beds at a time and getting them raised a few inches above grade before planting.

   Science has some good evidence to support no-till and no-improve, but I’ve seen a marked difference in results between the improve-and-plant people vs. the dig-holes-and-plant-right-into-the-existing-ground people. The former seem to have way better results in our driveway-like yards.

   If you’re interested in more detail about this whole topic, check out Dr. Linda Chalker-Scott’s “Horticultural Myths” site. 

   Especially check out the parts on “Soil Amendments” and the article on Newspaper and Cardboard Sheet Mulches under “Mulches.”