How To Prepare Organic Garden Soil For Vegetables

Building a sustainable lifestyle through gardening is something Marlene finds rewarding. Sharing tips with other gardeners is a true joy.

Plants grow best in soil that is well-nourished.

Markus Spiske

Aside from plenty of sunlight and water, the proper pH levels and nutrient-rich soil provides a healthy environment for plants to grow well. Knowing the characteristics of your soil is something many novice gardeners fail to do before planting, and then they become discouraged with the process of growing their own food.

When I became serious about growing a productive garden, I wanted the best condition I could provide for my growing endeavor. I tested the soil to determine which nutrients would be needed to help my plants grow healthy food for the people who would be eating the food in my household.

You do not have to test your soil if you prefer not to, but then you would have to hope that your soil is rich and ready for planting as is. The results may or may not be favorable to your satisfaction. Yellow-tipped leaves, scrawny limbs, and low yield are just a few of the signs which show you that your soil is not suitable for the vegetables you are attempting to grow in your garden.

One other thing that is important immediately after planting your garden is to provide mulch. Mulch is a top layer that adds additional protection to the soil and plants.

Let's look at pH levels, fertilizers, and mulching.

pH Levels

First, let's look at the soil's pH levels.

Before planting your vegetable garden, determine the pH level of your garden soil. pH is the soil's acid or alkaline level.

A neutral level on the scale is a pH of 7.0.
An acid level on the scale is from 1.0 up to 6.9 (with 1.0 being the most acid).
An alkaline reading is 7.1 to 14.0 (with 14.0 being the most alkaline.

Most vegetables prefer to be in soil that is slightly acid with a pH reading of 6.0 to 6.8.

Soil preparation is important for healthy plants.

Author

The pH level of your soil should be tested about every two years. Depending on the results of the pH test, it could take a month or more to get the soil adjusted to the intended level. Any time is a good time to test the pH level in your garden soil; however, many gardeners say fall is the best time to measure your soil's pH level because oftentimes, gardeners do not plant a garden during the colder months of the fall season. With the garden bed empty, gardeners have a full season to adjust the soil before planting in the warmer months of spring.

Considering that it may take some time to get the soil just right, be sure to factor soil adjustment time into your garden planting schedule.

Plants grow best in soil that is well-nourished. Knowing the pH level in the soil allows you the ability to adjust the soil to a level that helps your plants thrive. The only way to know the pH level is to test the soil. Once you receive the results of the test, you will know what type of soil you have, and you will know what to add to adjust the soil's pH levels.

There is an expensive way to test your soil for the most accurate results, and there is a cost-effective way of testing that is generally good enough for the average home gardener.

Expensive: Send a sample to a commercial soil laboratory. The cost to use the services of a commercial laboratory is about $100.
Less expensive: Send a soil sample to a Cooperative Extension Service which is usually offered through a state university. The cost of their service is about $20.

Least expensive: Purchase a soil pH test kit or use a digital soil pH meter to do the test yourself. The cost for these test methods ranges from about $7 to $20.
Soil pH Test Kit: The soil pH test kit is an economical home test tool that is easy to use and provides fast results. The kit has everything you need (except the clean bowls you will need to place the soil samples in). The kit comes with numbered step-by-step instructions that make it easy to test your soil, even giving examples of where to collect the soil. To adjust the soil, you may need to apply material such as dolomitic or calcic limestone, hydrated lime, iron sulfate, or aluminum sulfate. The kit has instructions that tell you how to adjust the soil, giving information about how much material you need to apply.

Digital Soil pH Meter: The digital soil pH meter is an effective tool for measuring the soil's pH level. It is also easy to use. You simply collect a sample of soil, mix it with water, and then wait for about five minutes before placing the meter in the soil and water. The meter records the results.
Unlike the pH test kit, the meter generally does not provide a pamphlet offering additional information about soil adjustments.

Soil Test Kit or Digital pH Meter?

My personal preference is the test kit. Call me lazy, because the only drawback from using the meter is that the dirt has to be cleaned off the prongs after each use. With the kit, I just throw out the used product.

Video Explaining How to Test the pH Level of Soil

Adjusting the pH level in your soil is an intricate process of adding lime and other chemicals that change the pH level of the soil. Before attempting to change the chemical makeup of your soil, be careful, or else you could inadvertently destroy the health of your soil and make it unsuitable for planting.

The following video explains the basic process of how to adjust the pH level of your soil.

How to Adjust Soil pH

Adjusting the Soil

Properly balanced soil needs a certain amount of nitrogen (N), phosphorus (P), and potassium which is also known as potash (K). Additionally, other soil nutrients include calcium and magnesium. Proper adjustment of the soil depends on the type of soil you have. Do you have clay soil? Is your soil sandy? The denser the soil, the longer it will take for the soil to adjust to the desired pH level. You will need to allow time for the additives to become incorporated into the soil before planting vegetables.

The number of additives you apply to adjust the soil will depend on the starting pH level, the type of soil you have, and the requirements of the vegetables you plan to grow in the soil.

Here are some basic guidelines for adjusting the soil to a 6.0 – 6.5 pH level that most (but not all) vegetables require.

Soil is Too Acidic: If the soil is too acidic (below pH level 7.0), add ground limestone or dolomitic limestone to the soil to neutralize the acidity. Generally, for acidic soil, apply 5 pounds of limestone per 100 square feet to raise the pH by one point. Some gardeners raise the pH level of the soil by applying wood ash. When using wood ash, apply 2 pounds of wood ash per 100 square feet to raise the pH by one point.
Soil is Too Alkaline: If the soil is too alkaline (above pH level 7.0), add ammonium sulfate, urea, and ammonium nitrate to lower the alkaline level. It is safe to apply 2 pounds of additives per 100 square feet to lower the pH by one point. Some gardeners apply pine needles, shredded leaves, sawdust, and peat moss. Generally, you will need to add about 2 pounds of material to 100 square feet to lower the pH by one point.

Note: If you need to raise or lower the pH level of the soil by more than one point, try adding half the amount more of additives per 100 square feet. Then wait about a month. Test the soil again to read the pH level. If the pH level is close enough to what you need (within .5 -1 point), leave the soil alone. Do not take a chance on adjusting the balance to a precise level because when the level is close enough, adding more chemicals may change the pH level beyond the intended level.

Table of Vegetable pH Preferences

In the table shown below, you will find the most common vegetables and the preferred pH level. These are just guidelines because, depending on environmental conditions, these numbers can vary slightly up or down.

Vegetable pH Preferences

Most vegetables can tolerate pH levels a point or two either way. The pH levels shown in the table are plant preferences.
Vegetable	pH
Artichoke	6.5 - 8.0
Arugula	6.0 - 6.8
Asparagus	7.00
Basil	6.0 - 7.0
Beans	6.0 - 6.8
Beets	6.5 - 7.0
Bok Choy	6.0 - 7.5
Broccoli	6.0 - 7.5
Broccoli Raab	6.0 - 7.5
Brussels sprouts	6.0 - 7.5
Cabbage	6.0 - 7.5
Carrots	6.0 - 6.8
Cauliflower	6.0 - 7.5
Celery	6.0 - 7.0
Chives	6.2 - 6.8
Collards	6.0 - 7.5
Corn	6.0 - 6.8
Cucumber	7.00
Dill	5.5 - 7.5
Eggplant	6.80
Endive	6.2 - 6.8
Escarole	6.0 - 7.0
Fennel	6.0 - 6.7
French Sorrel	5.5 - 6.8
Garlic	6.2 - 6.8
Kale	6.0 - 7.5
Kohlrabi	6.0 - 7.5
Leeks	6.2 - 6.8
Lettuce	6.2 - 6.8
Melons	6.5 - 7.5
Mustard Green	6.0 - 7.5
Okra	6.0 - 7.5
Onions	6.2 - 6.8
Parsley	5.0 - 7.0
Parsnip	6.0 - 7.0
Peas	6.0 - 7.0
Peppers	6.0 - 7.0
Potatoes	4.8 - 5.5
Pumpkins	5.8 - 6.8
Radicchio	6.0 - 6.7
Radish	5.8 - 6.8
Rhubarb	5.5 - 6.5
Rutabagas	Grows in any pH
Scallions	6.2 - 6.8
Shallots	6.2 - 6.8
Spinach	6.5 - 7.5
Squash - Summer	5.8 - 6.8
Squash - Winter	5.8 - 6.8
Sweet Potatoes	5.5 - 6.0
Swiss Chard	6.0 - 7.0
Tomatoes	6.0 - 6.8
Turnips	6.0 - 7.5
Zucchini	5.8 - 6.8

Plant Food Is Soil Fertilizer

Plant food adds nutrition to soil.

Author

Plant Food Fertilizes Soil

Now, let's look at your soil's nutrients that come from plant food, also known as fertilizers.

Fertilizer is basically "food" for the garden. And, just like humans need more of one nutrient or another to stay healthy, it is the same with plants. Depending on your soil and the plants you plan to grow, in order to grow healthy vegetables, you may need to provide more of one nutrient or another.

A basic vegetable garden is going to need nitrogen (N), phosphoric acid (P), and potassium (K) (sometimes called potash).

If you know specifically what your soil needs, you could mix your own combination of nutrients. However, without actually testing the soil, your best decision is to purchase a pre-mixed bag, box, or bottle of vegetable fertilizer.

When you look on the fertilizer label, you will see numbers such as 5-5-5, 10-10-10, 4-8-10 or any combination of these three numbers. These numbers tell you the proportion of each macronutrient contained in the fertilizer. The first number is always nitrogen (N), the second number is phosphorus (P), and the third number is potassium (K). Gardeners refer to this as the "N-P-K" ratios. The numbers reflect the available nutrients, by weight, contained in that container of fertilizer. So, if you have a 100-pound bag of fertilizer that has an N-P-K ratio of 4-8-10, that container has 4 pounds of nitrate, 8 pounds of phosphate, 10 pounds of potassium and 78 pounds of filler material. The filler could be sand, grains, wood chips, or whatever the manufacturer uses to make up the 100-pound container.

There are many brands of fertilizer from which to choose and you can drive yourself crazy trying to figure out which brand to buy. My experience with brands is that one brand is just as good as another. Chemicals are chemicals! I assume the package is correctly labeled. I simply choose the brand that is the least expensive and also contains the nutrients needed for growing healthy vegetables.

Sprinkle the fertilizer lightly onto the soil and mix well through the top six to twelve inches of soil.

Follow the directions on the fertilizer bag to be sure you are treating your soil correctly. More is not better because applying too much of the chemicals in fertilizer mixtures might burn the delicate seeds before they have a chance to grow.

What Nutrient Ratios Are Best for Vegetable Gardens?

If you test your soil, then you will know what ratios of fertilizer nutrients your soil needs. If, on the other hand, you do not test your soil, to be on the safe side, look for a moderate ratio of the following nutrients for vegetable crops.

Nitrogen: 5%
Phosphoric acid: 5%
Potash: 5%

Or, an N-P-K ratio of 5-5-5.

If you feel you have poor quality soil, it is safe to go with a higher N-P-K ratio of 10-10-10 which is readily available in most garden supply stores.

Some vegetable crops may need additional amounts of one element or another. As you read further about your particular crop, you may discover that you need to supply more of a specific nutrient to that plant. For example, corn grows better with a fertilizer that contains more nitrogen and phosphorus than potassium. So, for the corn, you may want to look for an N-P-K ratio of 16-16-8.

When feeding plants additional food, apply the additional food to the top of the soil after planting. In other words,

Apply and mix the regular fertilizer to the entire crop.
Then, plant your seeds.
And then, once the plants have grown to reach a height of about 2 to 3 inches, add the additional nutrient mix on top of the soil for the particular crop that needs the additional nutrients.

Note: Be careful about adding too many nutrients all at one time because too much of a good thing may cause the seeds to burn. After mixing the regular fertilizer to the entire bed, you want to wait until the plant has grown foliage and roots so that the developed roots can safely absorb the additional nutrients that you plan to add later.

Table of Vegetable Nutrient Preferences

In the table shown below, you will find vegetables that are known for needing additional nutrients.

Vegetable Nutrient Preferences

Determine which nutrients are best for your vegetable plants and then fortify the soil accordingly. The vegetables in the table are plants that require more of one element over another.
Nutrient	Description	Vegetables that need more of this nutrient
Nitrogen (N)	Nitrogen is the main component of chlorophyll which helps plants utilize sunlight energy. Nitrogen is the building block for protein in plants. Nitrogen helps promote health in leaves and foliage	Cabbage, Corn, Lettuce, Tomato, Squash
Phosphorus (K)	Phosphorus helps in cell division and developing a strong root system of the plant.	All plants need phosphorus to survive.
Potassium/Potash (K)	Potassium, also known as Potash helps the plant in utilizing water and in synthesizing plant sugars to be used as food. Potassium helps the plant remain strong and resistant to disease, and also helps plants withstand extreme hot and cold temperatures.	Asparagus, Beets, Okra, Parsley, Potatoes, Radishes

Add Mulch to Your Garden Soil

Mulching

Finally, let's look at mulching.

Mulching is an activity which adds a layer of protection to the top of the soil. Mulch protects the plant from frost, keeps moisture from evaporating from the soil, and suppresses weeds. Mulch can be any type of cellulose or natural fiber such as shredded or chipped bark, composted food scraps, composted manure, grass clippings, newspaper (made with organic dyes), shredded leaves, and straw.

Natural, organic mulch will decompose and will have to be replenished each season, unlike cellulose material which does not decompose and stays in the soil for an unlimited time. I opt for natural materials. In fact, one year I purchased a bale of hay and found much success with that. The hay was very inexpensive, was pretty in the garden and lasted a full year before having to be replenished.

When mulching your soil, apply mulch debris on top of the soil about 4 to 6 inches deep.

Test the Soil and Add Necessary Nutrients

For the most vibrant and productive vegetables, take a little time to prepare your soil before planting. Make sure your soil has enough nitrogen, phosphorus, and potassium (potash) for the vegetables you wish to grow. Test your soil for pH balance and nutrient levels and then adjust the soil if needed. Finally, add mulch to protect the soil and your plants from extreme weather and to hold in all that nutritious soil.

I hope your gardening endeavors are successful and that your garden delivers an abundance of fresh vegetables for you to harvest and enjoy for many years.

This article is accurate and true to the best of the author's knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

Marlene Bertrand (author) from USA on February 07, 2020:

Hello Kemydbest,

I hope all goes well with your plans.

Kemydbest on January 14, 2020:

Thanks i have actually gained a lot. I hope to do something this year.

Marlene Bertrand (author) from USA on February 13, 2019:

Yes, Eric, it is certainly time to start thinking about getting into the garden again. I'm looking forward to it.

Marlene Bertrand (author) from USA on February 13, 2019:

Thank you Liberty Lawn Maintenance. Your feedback means a lot to me. I am sure I'll be reading plenty of your articles for more help on the subject.

Eric Dierker from Spring Valley, CA. U.S.A. on February 12, 2019:

It is about time to start here again.

Liberty Lawn Maintenance from 528-17750 Highway 10, Surrey, BC V3S 1K4 1-604-313-9990 on February 12, 2019:

I don't see any recent comments here but nonetheless great article. Thank you Marlene. Soil prep is key. I am eagerly awaiting the spring season when I can get my hands dirty in the garden! :) I am sure you understand.

Marlene Bertrand (author) from USA on January 05, 2017:

Happy New Year to you, too ChitrangadaSharan. And, thank you for your feedback. I absolutely love to spend time in the garden and this year I hope to plant more and harvest more. I don't have a lot of space, so my garden area is packed to the brim.

Chitrangada Sharan from New Delhi, India on January 05, 2017:

This is a very helpful and informative article about gardening!

I am saving it for my future reference.

I don't have much space for growing vegetables and other of my favourite plants right now but I may have in future.

As always an excellent hub with every detail, that we may need to prepare soil for a greater yield.

Thank you for sharing and a Very Happy New Year to you!

Marlene Bertrand (author) from USA on November 05, 2016:

Thank you, BlossomSB. A lot of this is written from the experience that comes from trial and error, combined with a LOT of reading and taking copious notes.

Bronwen Scott-Branagan from Victoria, Australia on November 04, 2016:

You have done a lot of research for this article and it is very helpful. Thank you so much!

Marlene Bertrand (author) from USA on November 04, 2016:

Hello Blond Logic. Here in California where I live the soil is clay-like. It is very dense and takes a long time to prepare. I didn't realize how important mulching was until I did it one year and it helped the veggies grow so much stronger. It actually made my job easier since I didn't have to tend to weeding so much.

Mary Wickison from Brazil on November 04, 2016:

Where I live we have sandy soil which is a challenge. We mulch and add compost, and it is slowly improving.

Excellent information about soil preparation for gardens.

Marlene Bertrand (author) from USA on November 04, 2016:

Hello manatita44. I was just reading your book when my computer alerted me of a new message and it happened to be you here. Anyway, I enjoy being in the garden. When things are growing well, it kind of reminds me of a well-painted picture. I can't help bringing my camera out each day to take photos. I know I have to put the effort in up front to reap the rewards later. And now my garden provides a good portion of the food I consume. A little expensive in the beginning, yes, but it is all worth it in the end I think.

manatita44 on November 04, 2016:

Well Marlene. A lot here. Did not know that so much was involved. A great way to cultivate good Karma, perhaps. A little expensive to and requiring time. My garden is terrible! No time or know -how. Good luck, considering the money and time. Much Peace.

Marlene Bertrand (author) from USA on November 04, 2016:

Thank you for your feedback Venkatachari M. I learned a lot by trying things from memory of the gardens my grandparents and parents had. But, I learned the technical stuff from reading and taking notes. I am truly glad you enjoyed reading this article.

Venkatachari M from Hyderabad, India on November 04, 2016:

This hub is a very thorough and complete guide to the preparing and seasoning of soil in your gardens. You have done it so profoundly. Thanks for sharing this valuable information.

Marlene Bertrand (author) from USA on November 04, 2016:

Bill, thank you for your validation. Ask me how I learned all of this stuff! Yep! Trial and error. Then I got smart and started reading the "why" for gardening. It helps to know what to do. I truly enjoy watching my garden grow.

Bill Holland from Olympia, WA on November 04, 2016:

For anyone reading this, Marlene is "right on" with everything she said. Prepare first, reap the benefits second.

Great stuff, my friend!

Marlene Bertrand (author) from USA on November 03, 2016:

Hello Ericdierker. Believe it or not, this little article was actually written from research I did because I wanted to know what nutrients my roses needed. I tend to pay more attention to the vegetable garden and now my roses look like they need a little attention too. After pruning, I'll give them the extra nutrition they need so next year they will be absolutely gorgeous.

Eric Dierker from Spring Valley, CA. U.S.A. on November 03, 2016:

Very cool stuff. I think we need to know that when we go all growing organic that that does not mean we eschew the good parts of science. As I say this I am feeling guilty about not providing more nutrients for my roses.