Grow Your Own Food: 5 Tips For Perfect Soil

By Anthony Todd in Food on May 6, 2013 2:30PM

Last time on "Grow Your Own Food," we discussed the steps for planning your garden while the ground was still frozen and/or flooded. Over the last couple of weeks the weather has brightened up, the trees have started to sprout leaves and those of us who love gardening have gotten that old familiar feeling — time to put our hands in the dirt.

But for home gardeners, "dirt" isn't all that simple. How do you get soil that will grow huge, perfect vegetables? What if you're a container gardener? There are so many different bags at your local garden store, and if you buy 10 or 20 cubic feet of the wrong thing, your back (and your wallet) is going to be seriously pissed. That's why we've asked our resident garden expert (and all-around lovely person) Sara Gasbarra to help us make sure our dirt is just perfect.

1.) Don't buy the wrong stuff.

We were at Home Depot a couple of weeks ago, and the sheer number of different bags of dirt and dirt-like substances was astounding. You could've built a whole extra Home Depot in the parking lot just out of the bags of dirt in the garden center.

What the heck should you buy? Most of the products that you will see fall into three categories: Topsoil, Peat and Potting soil. If you're a container gardener, only one is gonna do it for you. Gasbarra explains:

"Use a high quality potting soil mix for your containers, never use top soil. Think of top soil as a product that dresses your shrubbery, patches bare spots in lawns and fills holes. It's dense and often low in nutrients and not ideal for growing vegetables. Peat moss is typically used as an additive to soil — it's made of decomposed fibers, organic plant and soil matter and loosens heavy soils and will improve moisture retention in your garden bed."

Potting soil often comes pre-fertilized, so make sure you get the right sort — you don't want to buy soil that is customized for roses when you are trying to grow lettuce. In other words, unlike us, don't just buy based on how pretty the pictures are on the bag.

2.) Don't just start digging in your yard.

Even if you're an apartment dweller, you may be tempted to dig into your courtyard/backyard/random bare patch of ground. If you have a yard of your own, it looks like it's crying out for growing things, right?

Wrong. Much of the soil in Chicago is badly contaminated, and even the big community gardens use raised beds. You might be able to pull it off, but don't take a chance.

"If you plan to garden in ground in the city, you must test your soil for lead. This is easy to do and costs less than $20 for each test and results come back in about 5 days. Located near UIC, companies like Stat Analysis even have a convenient drop off box for your soil samples.

If your soil test comes up with high levels of lead and and you still would like to utilize your backyard space (and forgo container gardening), you will need to build raised beds at least 18” high. Spend the extra money and go with untreatred cedar rails for the beds, as they will wear longer. You will also need to create a barrier between the existing lead tainted soil and the fresh soil you fill the bed with. Lake Street Supply carries barrier landscape cloth that can be placed at the bottom of your raised bed to prevent the soils from incorporating. Lake Street Supply also carries a wide range of high quality organic composted soil specifically blended for vegetable gardening, sold by the cubic yard."

Or, you can do what we are doing and cover your porch in Earth Boxes. That way, you know exactly what is going in the boxes and there's no need to worry about contamination.

3.) Buy the right soil for containers

If you're a container gardener, your task is a tiny bit easier — you control everything that goes in, from fertilizer to water to dirt. But you have to make sure to get the right stuff, or you'll end up with some very heavy, very dead ornamental boxes on your porch.

"I would recommend a high quality organic container soil — my go-to product for my restaurant gardens is Fox Farm’s Happy Frog. It's super lightweight and perfect for container growing, plants just love it and thrive in it. Dr. Earth and Baccto also have great potting soil mixes. You can find these products at any Chicago area Brew and Grow location, Christy Webber Farm and Garden Center in West Town or at Sprout Home in Ukrainian Village. These products cost more, but soil is key to a garden’s success, so it's worth the investment."

4.) Pick the right fertilizers before you start.

We'll be talking about fertilizers in more detail in a later installment, but it's good to build up your soil a bit before you start. Compost is always wonderful, but gardeners starting from scratch might not have any. There are a bewildering array of products to choose from, all promising luscious, perfect success. What to do?

"Limit yourself. You don’t need it all, but you want to go organic. For my restaurant gardens, I stick to a combination of two simple organic fertilizers: Fish and Seaweed emulsion (Neptune’s Harvest Fish and Seaweed Fertilizer 2 - 3 - 1) and a granulated fertilizer such as Espoma’s Plant-tone 5 - 3 - 3, which contains a blend of beneficial microbes and breaks down gradually over time. You can find Espoma products at most garden retailers in the city. The Neptune’s Harvest product line can be found at Gethsemane Garden Center.

When preparing your soil before planting, I incorporate the Plant-tone into the new soil with a trowel or shovel — make sure to follow the guidelines on the packaging for the proper amount to use for the size of your container or bed. When popping in transplants, I will add a small amount to the transplant hole before I place the plant in. I do this for my tomatoes, peppers, eggplant and herbs. After planting, I will water in the entire garden by hand with the diluted fish/seaweed emulsion mixture. (Note: Fish emulsion can scorch plants on hot sunny days, so make sure you apply this fertilizer treatment on an overcast day or early/late in the day when the sun is down!)

There are other great options for amending your soil out there as well — earthworm castings are an excellent additive to soil and a ittle goes a long way. Growing Power sells bagged earthworm castings from their own on-site vermiculture beds at Green City Market. Its a fantastic product!"

5.) Go organic.

When you are confronted with the millions of bags of dirt, some say organic and some don't. The organic ones, as you'd expect, are more expensive. Is it worth it?

"Go organic with everything, including soil and fertilizer. Its simple: you just don’t know what sorts of chemicals are going into that non-organic soil. Your plants are feeding off the nutrients in the soil and you in turn will be feeding off your plants. You want your soil to be organic, ensuring that your garden is producing veggies grown organically."

Start playing in the dirt!