How to Prepare the Soil for a Vegetable Garden

Anyone can begin a vegetable garden, whether it’s in raised beds, garden boxes, or in a traditional garden. The first step to growing bountiful vegetables is to understand the health of your soil. Once you know how to create ideal soil conditions, you can grow just about anything.

Preparing your soil for a vegetable garden begins with knowing what your soil is made of. Then, you will need to add nutritious organic material or compost, aerate the soil by tilling or double digging, and keep pesky weeds away by weeding your vegetable garden regularly. 

Vegetable gardens are fun to grow, with the added bonus of being able to enjoy the spoils of edible, seasonal crops at harvest. But before you get gung-ho about planting, the first thing you should do is examine your soil.

Learn What Your Soil is Made Of

First, look to see what your soil is made of. The ideal soil for planting a vegetable garden is rich, loose soil with plenty of microbes and bugs to keep it healthy. 

There are 6 types of soil: clay, sandy, silty, peaty, chalky, and loamy. Clay soil and sandy soil are red flags for vegetable gardeners. While some crops can grow in clay or sand, healthy vegetables won’t thrive in these conditions. You can tell if your soil is made of clay or sand by picking up a handful of dry earth, wetting it under a faucet, and rolling it into an oblong ball in your hand. If the ball crumbles, you have sand. If the ball can be polished into a dull sheen, you have clay. 

In sandy soil, the necessary water needed to nourish healthy vegetables washes away, leaving them without enough moisture. And in clay soils, the roots of the vegetables do not have ample room to spread and grow under the high-pressure conditions of the tight, sticky clay. 

But don’t give up hope if your soil is clay or sandy. These soil conditions can be amended with time and effort. 

To amend sandy soil, it’s recommended to add compost, manure, and other soil builders like shredded leaves or peat moss. It’s best to add at least 3-4 inches of organic matter to your garden’s soil every week. If you live in hot, dry conditions, you may want to add even more. It may be a lot of work, but it will be worth it. These additives will keep the moisture in and build the overall health of your soil. 

If you’re not sure about your sandy soil conditions, but you’ve put in the work to fix it before planting, try planting just root vegetables your first season. Carrots and beets grow beautifully in loose soil, as long as it’s healthy. 

To amend clay soil, it’s best to loosen up the soil and add organic matter like compost, peat moss, or gypsum. As a general rule, add a layer of 3-6 inches of organic matter on your soil before you try and plant your garden. Keep up this practice regularly, working it down into the top 10-12 inches of your soil. That area—the top layer of your soil—is where most vegetable roots grow. After the growing season ends, turn your soil once more, and add about 1-3 inches of mulch. That will keep the healthy additives in place for the following year. Repeat this practice until you’ve set a nice foundation for your garden. 

Amending the soil to get it just right for your vegetable garden takes some elbow grease and some know-how. But with the right tools and the right amount of effort, you can grow your own vegetable garden.

If you’re still unsure of your soil conditions, or if you want to learn more about your soil, it’s a good idea to purchase a soil test.

Related: How to start a vegetable garden

Soil Tests: Get the Best out of Your Soil

Soil tests are easy to find and range in price from under $10 to over $100. Most soil tests that were best rated by user surveys online fell into the $30-$40 range. The point is, testing your soil when you’re ready to begin your garden and once every 3 years or so after that is well worth the cost. 

Most soil tests offer a mail-in service. All you need to do is collect a small sample of soil and mail it in. Soon, you will receive your results.

Depending on your soil test, it can contain a lot of information, including your soil type. But the most important thing you’ll want to look at when receiving your test results is your soil’s pH level. 

If your pH is too low or too high, there are steps you can take to balance it out, making it a healthier, happier place for your vegetables to grow. 

Most plants grow best in soils with a pH between 6 (slightly acid) and 7.5 (slightly alkaline). But if your pH is lower than 6, it is too acidic. If it is above 7.5, it’s too alkaline. 

To raise the pH in acidic soil, add limestone a little at a time, 20 lbs or less for every 100 sq. ft. A little at a time is recommended because it is easier to raise the pH if your soil is off than to lower it. 

To lower the pH in alkaline soil, add about 1 lb. of sulfur per every 100 sq. ft. If your soil pH is very alkaline, over 8.0, you can add up to 2 lbs. of sulfur per every 100 sq. ft.

It may take some time to create ideal soil conditions, but don’t give up. And if you want your soil to get healthier more quickly, try adding compost to the mix. 

Compost is the Secret Weapon

Compost is the “Mr. Fix-it” of the gardening world. There are very few soil issues that cannot be amended with soil-nutritious compost. 

Of course, not everyone has their own compost pile at home. You can absolutely buy organic compost from most garden stores, but composting is actually a pretty simple habit to start. A compost barrel costs less than $100, and a compost bin can be made from everyday materials that cost less than $50. Once you have a compost bin or barrel, then all you need to do is collect organic material, then churn and burn. 

Churning the pile with a pitchfork keeps your compost aerated and warm, breaking it down into the proper nutrients to nourish your garden. Churning the handle on a compost barrel is even easier. 

If you’re churning and you notice that your compost is very dry, you can add a bit of water. Dry compost is not going to stay warm enough, but it also shouldn’t be sopping wet, either. Compost that is too wet can be fixed by adding more “brown” material. 

If your area is going to get heavy rainstorms or experience extremely high temperatures, it’s best to cover your compost pile with a tarp to keep the moisture level at 40%-60%, and to keep it aerated and healthy. 

Since compost is just a mix of organic materials that you normally throw in the trash, you will not run out of things to toss into your compost pile. 

Compost must consist of “green” items and “brown” items. The correct ratio of brown to green is still being disputed, but keeping it at 1 part green and 3 parts brown when possible creates “hot fuel,” keeping your compost cooking. 

Green items add nitrogen to the pile. These include veggie scraps, fruit peels, coffee grounds, green grass, and plant clippings. 

Brown items add carbon or carbohydrates. These include leaves, straw, wood shavings (unpainted and unstained), dead grass, twigs, cardboard, and printer paper without ink.

Manure is also great to add to compost, but make sure it is from vegetarian animals only. 

Compost is a perfect additive to any soil, but it does wonders to amend sandy soil and clay soil:

1. Compost helps sandy soil retain water and nutrients.
2. Compost loosens tightly bound clay or silt soil so roots can spread, water can drain and airflow can improve. 

Indeed, compost is the magic ingredient that makes any soil easier to work. But how does it work? 

Compost brings diverse life to the soil and feeds the bacteria, fungi, insects, and worms that make the soil a living, healthy environment. Those insects, worms, and bacteria burrow through the soil keeping it aerated. And when the green matter in compost breaks down, it creates soil-friendly nitrogen which the bacteria convert into plant-healthy nutrients.

Composting also keeps food scraps, coffee grounds, cardboard, and many other items out of landfills. Also, since compost piles need “brown” material such as grass clippings and tree leaves, you won’t need to leave your yard waste bagged up at the curb, saving you time, energy, and the cost of yard waste bags. Once you start composting, you may not want to quit. 

Related: How to start a vegetable garden

Soil Aeration 

Aerating soil before your initial planting not only improves airflow to your plants but increases the overall health of your soil. Soil particles can sometimes get so densely crammed together, they prevent vitamins, air, and water from properly circulating in the ground. Vegetable gardeners should turn over the soil twice a year, in spring and fall, until your soil improves. After your soil is healthy, it’s good practice to leave it undisturbed, feeding it organic matter from the top and allowing worms and insects to aerate the healthy soil naturally. 

If you are just starting, you will need to loosen compacted soil. There are two great methods for loosening your garden’s soil: 

1. Tilling: Tilling before you plant in spring increases airflow in soil and stimulates the activity of helpful bacteria. The bacteria help break down organic matter more quickly, releasing heat as energy. Tilling soil in fall sets you up for the following growing season. It’s good practice to add organic matter while tilling in fall, such as the season’s dying vegetable plants, grass clippings, and decomposing fall leaves. 
2. Double digging: Simply put, double digging involves removing the top layer of soil, exposing the subsoil or hardpan beneath. Then, you can add organic matter and replace the soil on top. Double digging helps to break up the soil, increasing airflow to the deeper part of the bed where roots thrive. It’s good practice to add organic matter while the soil is dug up, then again on top.

Already healthy soil is best left undisturbed. If you have spongy soil full of a healthy life, you don’t need to churn it. But if your healthy soil gets a lot of foot traffic, it may be a good idea to till again. 

Read also: How to Till a Garden

Pull those Pesky Weeds

Also, don’t forget to weed your soil. Be sure to weed thoroughly as you’re preparing your soil, and then regularly thereafter. Regular weeding keeps the weeds’ root systems from penetrating into your garden, creating disastrous conditions for your vegetables.

The best way to pull weeds is to pinch them at the bottom, then slowly wiggle and pull to get the majority of the root system out. The roots of weeds can easily sprout new plants, so you don’t want to leave them under the soil. 

Weed your garden at least once a week. The best time to weed is after the rain when the ground is damp and soft. That way, when you pull your weed gently from the base, the root system will more likely come all the way out. If you don’t have rain coming, early morning weeding is also a good idea. Depending on where you live, there may be some morning dew keeping the ground moist. If that’s not the case, you can weed right after watering. 

Regular, weekly weeding not only keeps your garden’s root systems healthy but also keeps weeds from spreading. If weeds are not allowed the ability to seed and spread, then you’ll have to deal with far fewer weed issues. 

If you follow all of these practices—testing your soil, adding compost, aerating, and weeding—you will have healthy garden soil to grow a fruitful vegetable garden. 

Resources

• Wisconsin Horticulture Division Extension