New — and old—garden success begins with raised beds!
Q. Mike: I just moved from Texas to New Jersey and have a sunny, grassy backyard I want to prep for a vegetable garden. Any 'first step' advice? I was thinking about tilling it all up and putting some topsoil down when the ground became soft enough. Thanks.
- ---Eric; originally from Michigan, then Houston, now Swedes boro, PA
I want to create a small raised garden, maybe 5x5, for herbs, tomatoes and peppers. I do not want to plant anything in the existing ground; I think it may have a lot of chemicals in it. I will get new soil from somewhere else. How deep should the new soil be?
- ---Dee in Newark, Delaware
We're recent transplants from New York City, and want to take up our lawns to plant flowers and vegetables. We can make three raised beds that will be 9x3 feet in the back yard; the front is only about 9x4 total. What should we be doing now (or when the ground warms up a little) to be able to plant this spring? Visitors will be bringing us some compost this weekend; should we try and work it into the ground, or wait closer to planting time? If we try it this weekend, should we cover the ground with mulch afterwards, and what kind of mulch is best? Thanks!
- ---Winifred in Roxborough, PA
A. Ah, to be a newbie gardener again—the thrills, the excitement, the rookie mistakes ("nobody told me tomatoes were vines!")…
Anyway, this is the perfect time of year to plan the building of new gardens—and the improvement of existing ones. But folks in cold climes shouldn't actually do anything besides plan just yet. Wait till the soil warms up and dries out before you start trying to work it. Yes, this means that you'll probably get a later start than you were hoping for. Good! You'll burn out fast if you try to do too much too soon. And we're going to help you create a system that will allow you to start super-early NEXT season if you like.
First, if grass is growing where you want a garden, DON'T till it all up—unless you plan to only grow grass in your new garden. Use a sharp instrument like a linoleum knife to cut foot wide sections, and then roll them up like a carpet. Use this sod to start a lawn somewhere else; or turn it upside down, let the grass die, and use it as mulch around your plants later in the season.
Now let's plan some raised beds. Nine by three feet is an excellent design; five by five is not. Raised beds should never be more than four feet wide, so that you can always reach the center without stepping into them. Keeping your big feet out insures that the soil will stay loose and light, allowing you to start gardening in future seasons without any tilling or turning to loosen up flat, compacted soil. Raised beds can be as long as you want—the longer the better, in fact, to maximize your growing space.
Be sure and wait till the soil is dry several inches down to do ANYTHING other than grass removal. If you try to work wet soil, you'll just make a big muddy mess. And go slow! Don't try to accomplish everything the first year; start with a couple of raised beds the first season and add more every year. You garden-horny former New Yorkers should be content with getting the back yard together; save the front for next season.
Map it all out with stakes and string, allowing two feet in between your beds for walking lanes. Shovel some of the dirt from those lanes up onto what will become your beds, and then mix in high-quality compost until the beds are about a foot higher than the surrounding area. You can allow the sides to slope naturally or frame them using local field stone, naturally rot-resistant wood like cedar, locust or Osage orange, or faux landscape timbers made of recycled plastic or plastic and wood composites like Trex. Don't use toxic materials like pressure treated wood or old railroad ties. (You'll find more raised bed framing info at this previous raised bed Question of the Week: Raise High Your Garden Beds, Growers!)
And don't mulch now. You want to leave the soil bare early in the season to allow the sun to warm and dry it. After your plants go in, spread an inch or two of shredded fall leaves or compost around them to prevent weeds and conserve soil moisture. Some locally available mulches, like cocoa hulls and pine straw, are also excellent choices. Don't use any kind of wood—chips, bark or root; it will steal plant food from the soil. And don't use that nasty rubber mulch—the old tires it's made from contain toxic amounts of zinc and other metals, and it stinks up the place in the summer. (Lots more mulching info at these previous Questions of the Week: Is Your Mulch Magificent? Or Miserable? and Keeping Mice Out of Your Mulch – And Your Mansion)
Back to Dee in Delaware, who's concerned about the prospect of dicey soil. If you know for sure that something really nasty—like an old factory or garage—was on the site, contact your local county extension service and arrange to have the soil tested for lead and other metals; some dirt is so dangerous it really needs to be removed.
If you're just being cautious, put down a couple inches of black and white newspaper sections where your beds will be and then cover that with a foot of good clean earth. My top choice would be a screened load of half compost, half high-quality topsoil. The newsprint should prevent your plant's roots from reaching down into the suspicious stuff.