Tomato Soil Preparation Tomatoes

A Helpful Guide to Prepare Soil for Tomatoes

Soil preparation is one of the important parts of getting a bounty harvest. Tomatoes can perform better if they get the right soil types they need.

In addition to balanced fertilization, proper irrigation, right tomato varieties, and planting zones play an important role in a successful tomato harvest.

Typically, early spring is the right time to prepare your soil. However, it may depend on your local planting zones when you actually start on.

How to prepare the soil for tomato plants

Do I need to prepare soil before growing tomatoes?

Yes! Of course, you do.

You must need to prepare your soil due to the following benefits:

  • Save money, time and labor over the season
  • Confirm healthy return of investment
  • Getting bounty harvest
  • Avoid soil-borne diseases
  • Getting risk free crop
  • Secure your next year cultivation disease-free
  • Making quality garden soil

Learn the basic soil types:

There are some common types of soil structures you will notice when preparing the soil.

Sandy Soil:

  • contain large particles
  • unable to bind together
  • good drainage system
  • proper aeration into the soil
  • unable to hold water and soil moisture
  • unfertile soil

Silt soil:

  • medium size particles
  • better drainage system
  • good aeration system
  • contain some nutrients
  • lack of organic components

Clay soil:

  • small particles
  • strong binding capacity
  • tilling is difficult
  • enrich in nutrients
  • extreme water holding ability
  • poor drainage system
  • less aeration supply into the soil
  • suitable for hot dry seasons

Rocky soil:

  • medium to large size particles
  • drain out quickly
  • less nutrient
  • heat quickly
  • difficult tilling process

Loamy soil:

  • This is an ideal combination of sand, silt, and clay soil best for growing tomatoes.

No matter what type of soil holds your backyard, it can be turned into an ideal soil for tomato plants applying proper soil amendments.

Taking a soil test first

A soil test is a primary job to do before starting soil preparation. There are plenty of soil test kits available in the garden stores. Just pick one and do the test.

If you found difficulties, contact your local extension center to finish the job.

Before taking the soil preparation you need to know which soil performs better for tomatoes.

Finally, compare your soil test result with the standard soil composition for tomatoes and figure out what you need.

Which soil composition is the best for growing tomatoes?

Every gardener dreams to get a healthy harvest. But poor soil structure brings a great challenge to achieve their goal.

This is one of the major issues to consider getting a bounty harvest.

So, the very first thing you have to know the features of an ideal soil structure before growing tomatoes.

A perfect soil structure contains the following particles with the right proportion:

Tomato soil types and texture:

Typically, you can grow tomatoes from any types of soil by taking proper amendments. But loam and sandy loam soils perform better.

Tomato plants established a deep rooting system to grow and set fruits. Well-drained, deep, and loamy soil helps the work easier.

Besides, heirloom tomatoes produce more flavorful fruits if they get the perfect composition of soil with organic matters. They like loamy soil enriched with humus or good compost.

Ideal soil pH for tomatoes:

Tomatoes perform better when the soil holds a pH level between 6 to 7 in scale.

Test your soil first to know the present level of the soil pH. You can get some cheap test kit available in the local garden centers or online stores.

Add lime to increase soil pH if the soil test result shows a low level of pH.

As well as, add sulfur to decrease soil pH if the soil contains high-level pH or alkaline soils.

Now the question arises, how much lime or sulfur does need your soil according to the soil test report?

-The best solution is to contact your nearest Agricultural Extension Center to measure the right proportion of the additives.

Ideal soil temperatures for tomatoes:

Don’t transplant your tomato plants outside until the nighttime soil temperatures drop below 55 to 60°F. and day time temperature in the 60s.

For indoor tomato plants, soil temperature should above 65° F. You can control your indoor temperature as you required by providing extra light.


Tomatoes grow well and thrive when they get at least 6 hours of direct sunlight and enough spacing surrounded by plants around 2-3 feet.

It also helps to receive enough airflow among plants.


Tomatoes need fertile soil to grow and set fruits. So, getting better yield, you need to check your soil fertility first to make necessary amendments. A Soil test kit will make the work easier.

Based on your soil test report you need to take necessary steps to provide nutrients to your garden soil.

Don’t apply fertilizer without testing your soil. It may sometimes harm your tomato plants due to over-fertilization or imbalance of fertilization.

Read more about tomato fertilization.

Tomato soil depth in a raised bed:

Tomatoes are deep-rooting plants. Their roots can reach up to 5 feet deeper into the soil to search for nutrients and water.

If the soil under the raised bed doesn’t contain a good mixture, you must need at least 2-3’ feet high raised bed.

On the other hand, if the garden soil under the raised bed contains good soil mix, you can grow tomatoes in a raised bed around 12 inches’ height.

How to amend the soil for tomatoes

It’s quite unusual to expect the perfect soil for growing tomatoes everywhere. Different planting zone got different types of soil and most of the soil does not contain the perfect combination.

So you need modifications to turn the soil fit for growing tomatoes.

Develop extreme sandy soil:

Sandy soil cannot hold the water for a longer period of time and drain out quickly. Besides, it means doesn’t contain necessary soil nutrients.

As a result, tomatoes rundown from the required nutrients and need quick watering.

To develop this soil condition, add organic components, coco coir or peat moss to increase the water holding capacity and nutrients.

Besides, good quality compost will provide the necessary nutrients and moisturizing the soil.

Amending rocky soil:

Turning your rocky soil into a nice garden patch is not very difficult but a little bit tricky. Most of the gardeners lose their hope of gardening when facing rocky soil.

First of all, select the area where you want to grow tomatoes. Slice the total cultivable area into several small pieces to make the job easier.

Remove the large heavy rocks first from the selected areas. Move the surface rocks and other debris using a flat rake.

Start tilling the area using a rototiller carefully to move out the large stones. Work slowly to save your equipment from damage and break down the soil around eight inches or deeper.

After filtering and removing the larger stones from the soil add 3-4 inches layer of organic compost on it. Mix coconut fiber, old rotted manure, organic components, and till them well with the rototiller. Do this several times for the best output.

Plant dipper your tomato plants to develop a strong rooting system. If you notice that your tomatoes keep dying, contact the nearest local extension center or nursery experts.

Develop extreme clay soil:

Clay soil holds small particles and strong binding capacity which stops absorbing water. And, once absorbed retain it for a long time.

To develop the soil condition, add necessary compost into the soil to provide nutrients and loosening the soil.

Add coconut fiber or peat moss for good aeration. It also helps to improve soil pH and reduces the acidic level.

For extreme hard soil add a part of sand to develop drainage system and proper aeration. Clay soil performs better in dry hot conditions.

Amending acidic (low pH) soils:

Using limestone to raise low soil pH and make the soil less acidic. There are different types of limestone available out there and all of them work well to increase soil ph.

Apply lime a few inches down into the soil for getting better performance.

Wood ash is an organic way to reduce the acidity of the soil. Dusting ½ inch of wood ash throughout the tomato plants and mixes it properly.

Amending alkaline (high pH) soils:

Sulfur is the most common way to amend alkaline soil. It is relatively cheap, easy, and safe to use. It can easily sprinkle over the soil to increase the soil acidity.

Sulfur is a slowly released element, so don’t apply more than 2 lb per 100 square feet at a time.

Sphagnum peat is an organic way to increase soil acidity and water holding capacity. Till deep as possible after applying the sphagnum peat into the soil.

Apply fertilizer which rich in ammonia, amino acids, or urea to acidify the soil.

Compost and organic matters are an important source of acidity. Applying regular compost and mulch over time can bring back the soil pH close the standard acidic level.

Amend the soil by tilling:

Till the soil overtime during soil preparation brings some major benefits. Such as:

  • Providing enough aeration into the soil
  • Helping the soil dry out if it remains wet
  • Ensure proper mixing of nutrients, organic materials, and fertilizers
  • Making a right mixture of soil additives like peat moss, coconut fiber, sand and compost
  • Control weed and provide more nutrients to the plants
  • Tomato roots can penetrate into the soil easily
  • Reduce the risk of some diseases

What to add in tomato holes for the best soil amendments?

Only growing fresh tomatoes don’t satisfy the home growers. Your homegrown tomatoes must be tastier than commercially grown tomatoes.

To improve the flavor and taste of the tomatoes, you need to add some extra elements in the hole before planting tomatoes.

Always keep in mind the soil test result to add any component in your garden soil for amendments.

Baking soda:

This is the best trick to get sweeter tomatoes. It mainly works for container tomatoes. Add some baking soda inside holes before planting tomatoes. This will decrease the soil acidity level and turn tomatoes sweeter.

Fish heads:

Using fish heads in tomato plants is an old method of fertilizing tomatoes naturally. It provides nitrogen, phosphorous, potassium, calcium, and other vital elements to the plants.

Bury the fish heads at least 12” inches deep to protect it from the attack of the critters.

Aspirin tablets:

Boost up the tomato plants’ immunity and protect them from blight diseases. Using 2-3 aspirin tablets each hole also produces a good harvest.


Crushed eggshells are a great source of calcium for tomatoes.  It boosts up the plants’ growth and protects blossom end root problems. Put some handfuls for each tomato holes whether it is garden bed or containers.

Epsom Salt:

Epsom salt fulfills the magnesium deficiency of tomato plants. Both garden beds and containers need 1 or 2 teaspoons of salt in each planting hole to do miracles.

Make sure that, your plant roots can’t touch the Epsom salt directly.

Old composted manure:

It is slowly released nutrients support the tomatoes over the growing season. You can distribute a couple of handfuls for each tomato plant.


It will fulfill the basic nutrient requirements for the plants. It develops the soil quality, drainage system, and retains moisture. Add 2-3 handfuls for each plant hole.

Kelp fertilizer:

Kelp meal is a complete package of slowly released micronutrients for tomato plants.

Add one cup of kelp meal in each hole at the beginning of the growing season. This can fulfill the demand of a tomato plant till the end of the season.

Bone meal:

It also works like kelp meals. It provides phosphorus to the tomato plants which is very essential for blossoming and setting quality fruits. Add one handful in each tomato hole.

Used Coffee Ground:

Composted coffee grounds are slow to release organic matters. Add the elements in each plant hole during transplanting tomatoes. It develops soil quality and a good source of fertilizer.

How to choose the best soil mix for raised bed and container tomatoes?

If you want to start tomatoes in containers, you must need a good potting mix.

Potting mix is often called potting soil, which is actually a soilless mixture of different organic and inorganic elements. It is called potting soil only because it helps to grow plants.

Potting mix is a balanced combination of the following ingredients:

Peat moss:

It is a dead fibrous material which can hold water and other nutrients for a longer period of time. It also develops soil texture and consistency.

Peat moss lasts for several years in soil and considered a bit more acidic with a pH around 3-4 in scale to grow tomatoes.

Besides, it doesn’t cover the potting mix all alone. And so, you need to add lime and other ingredients to bring the balance of the potting mix.

Coconut fiber:

Also known as coir fiber or coco coir or coco peat is the best alternative medium of peat moss, perlite, and vermiculite.

 This can hold water and other nutrients like peat moss and drain well too. Coco coir naturally holds the pH between 5.2 to 6.8 which is suitable to grow most of the plants.

Besides, coir fiber has some inherent natural capacity to grow new plants. It also contains potassium, iron, manganese, copper, and zinc.


Vermiculite is a soft brown spongy soil additive which is relatively sterile. It slightly contains natural pH and very light in weight. It can also retain water for a longer period of time and controlling the soil moisture.

Besides, it is a very good medium for sprouting seeds which best suits for tomatoes.


It is a white color, hard and highly porous materials used for lightening the potting soil.

This is very lightweight and provides enough aeration into the potting mix. It also helps to develop plant roots and suitable for alkaline loving plants.

Moreover, it releases its retaining water quickly.


This is the most inexpensive additives used in the potting mix for aeration. Sand can increase the weight of the container so use it maintaining the proper ratio.

Try to use coarse sand, silica sand, or beach sand to mix your potting mix.


This is one of the important additives of the potting mix. It provides necessary nutrients to the plants and holds the soil moisture.

Other ingredients:

Based on your potting mix and plant varieties you can add small amounts of fertilizer or slow-release nutrients with the mix.

Water holding gels:

Using water-holding gels into potting mix becoming popular day by day to the home gardeners. These gels can absorb water more than their size and release it slowly.

How do I confirm my potting mix is perfect for growing tomatoes?

To make a good potting mix of your own, mix together equal parts of each of the following additives:

  • One part – peat moss or coco coir
  • One part – compost
  • One part – sand or perlite
  • Mix proper portion of vermiculite depending on the plants you grow
  • Add organic components or other nutrients if required.

A good potting mix always –

  • Retain moisture
  • Stay wet free
  • Maintain a good drainage system
  • Proper aeration into the soil
  • Contain necessary nutrients and humus

If your potting mixes contain the above elements and fulfill the condition of a good potting mix, it would be a perfect medium for growing tomatoes.

You can also buy the potting soil from the local garden center, home improvement stores, or online stores.

There are different types of potting mix available out there and, the prices mostly differ the quality of the soil.

  • The standard potting mix is fairly less expensive. But you need to add some fertilizer, nutrients, and other elements to fulfill the criteria of a good potting mix.
  • You can also get some premium level mixture losing a few more bucks. But these types of mixtures mostly fulfill the demand of a good potting mix.
  • There have different branded commercial mixes also available in local and online stores. Choose the right one, compare to the criteria of a good potting mix.

Which soil combination is good for growing tomatoes in the rooftop?

The lightweight potting soil mix is the best choice for growing tomatoes in the rooftop.

Keep in mind the composition of a good potting mix for tomatoes.

Then, try to apply comparatively lightweight elements like coco coir or peat moss, vermiculite, perlite, and other organic components to combine the mixture.

Do I need to sterilize my garden soil before growing tomatoes?

Sterilizing garden soil or potting mix can reduce the risk of soil-borne diseases. This process kills harmful bacteria, viruses, and other pathogens.

Good quality potting soil must be sterilized. So, if you want to make a potting mix of your own, you should sterilize your garden soil before growing tomatoes.

Most of the premium or commercial levels potting mixes are sterilized by their companies.

If you didn’t grow any nightshade type plants like eggplants, pepper, potatoes, or tomatoes in your backyard before, you can skip this step.

But I recommend you to sterilize your garden soil if you grow tomatoes in the previous season.


A good soil preparation leads you one step ahead to get your dream harvest. Moreover, it also develops the fruit quality and ensures a disease-free yield.

Spending a little more time on preparing your soil can make other associated jobs easier like:

  • Good quality soil doesn’t need additional chemical fertilizer. It will save you money.
  • High-quality moisture soil doesn’t need frequent watering. So, it will save you time and labor.
  • Organic components and good quality compost bring an iconic taste and flavor in your tomatoes. It will fulfill your gardening goal.

So do some extra afford to make the best soil composition for your tomato plants.

Happy tomato gardening.


John Michael
John Michael is a self-help writer and a hobby gardener. Michael’s passion in writing is to inspire the beginner gardeners to not just “hang in there” or “make it through” but to thrive. He does this through blogging.

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