Tomato Soil Preparation Tomatoes

A Helpful Guide to Prepare Soil for Tomatoes

Updated: November 09, 2022

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

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

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

How to prepare the soil for tomato plants

Do I Need To Prepare The 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 on investment (ROI)
  • Getting bounty harvest
  • Avoid soil-borne diseases
  • Getting risk-free crop
  • Secure your next year’s cultivation disease-free
  • Making quality garden soil

Learn the Basic Soil Types:

You will notice some common types of soil structures when preparing the soil.

Sandy Soil:

  • contain large particles
  • unable to bind together
  • good drainage system
  • proper aeration of 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 ideal combination of sand, silt, and clay soil is best for growing tomatoes.

No matter what type of soil holds your backyard, it can be turned into 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.

Contact your local agricultural extension center to finish the job if you find difficulties.

Before taking the soil preparation, you must 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 of getting a healthy harvest. But poor soil structure brings a significant challenge to achieving their goal.

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

So, the first thing you must know is the ideal soil structure features before growing tomatoes.

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

Tomato Soil Types and Texture:

You can grow tomatoes from any soil by making 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 with organic matter if they get the perfect soil composition. 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 on a scale.

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

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

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

According to the soil test report, how much lime or sulfur does your soil need?

-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 reach above 55 to 60°F. And the daytime temperature is at 60°F constantly.

For indoor tomato plants, soil temperature should be above 65° F. You can control your indoor temperature as 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, to get a 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 must take the 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 a 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 of around 12 inches.

How to Amend the Soil for Tomatoes

It’s unusual to expect the perfect soil for growing tomatoes everywhere. Different planting zones have different soil types; most ground contains a different combination.

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

Develop Extreme Sandy Soil:

Sandy soil cannot hold the water for an extended time and drain out quickly. Besides, it means it doesn’t contain the necessary soil nutrients.

As a result, tomatoes are 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 moisturize the soil.

Amending Rocky Soil:

Turning your rocky soil into a lovely garden patch is relatively easy but tricky. Unfortunately, most gardeners lose their hope of gardening when facing rocky soil.

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

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

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

After filtering and removing the larger stones from the soil, add a 3-4 inches layer of organic compost. Mix coconut fiber, old rotted manure, and 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 solid 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 a solid binding capacity which stops absorbing water. And, once absorbed, retain it for a long time.

To develop the soil condition, add the necessary compost to provide nutrients and loosen the dirt.

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

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

Amending Acidic (low pH) Soils:

Using limestone raises low soil pH and makes the soil less acidic. Different types of limestone are available out there, and all of them work well to increase soil ph.

Apply lime a few inches down into the soil to get 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 mixing 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. In addition, it can quickly sprinkle over the ground to increase 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 a fertilizer rich in ammonia, amino acids, or urea to acidify the soil.

Compost and organic matters are essential sources of acidity. Applying regular compost and mulch over time can bring the soil pH close to the standard acidic level.

Amend the Soil by Tilling:

Till the soil overtime during soil preparation brings some significant 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 the right mixture of soil additives like peat moss, coconut fiber, sand, and compost
  • Control weeds and provide more nutrients to the plants
  • Tomato roots can penetrate 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 home growers. So 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 the soil test result in adding 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 the 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 plants with nitrogen, phosphorous, potassium, calcium, and other vital elements.

Bury the fish heads at least 12″ inches deep to protect them 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 in each hole produces a good harvest.


Crushed eggshells are a great source of calcium for tomatoes. It boosts up the plant’s growth and protects blossom end root problems. Put some handfuls for each tomato hole, whether a garden bed or container.

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 to 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. In addition, it develops the soil quality and 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 for a tomato plants till the end of the season.

Bone Meal:

It also works like kelp meals. It provides phosphorus to the tomato plants, 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 matter. Add the elements in each plant hole during transplanting tomatoes. It develops soil quality and is a good source of fertilizer.

How to Choose the Best Soil Mix For Raised Bed and Container Tomatoes?

To start tomatoes in containers, you need a good potting mix.

Potting mix is often called potting soil, a soilless mixture of 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 that can hold water and other nutrients for longer. It also develops soil texture and consistency.

Peat moss lasts for several years in soil and is considered a bit more acidic with a pH of 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 balance the potting mix.

Coconut Fiber:

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

This can hold water and other nutrients like peat moss and drain well. In addition, coco coir naturally has a pH between 5.2 to 6.8 which is suitable for growing most 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 that is relatively sterile. It slightly contains natural pH and is very light in weight. It can also retain water for extended periods and control soil moisture.

Besides, it is a perfect medium for sprouting seeds that best suits tomatoes.


It is a white, hard, and highly porous material used to lighten the potting soil.

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

Moreover, it releases its retaining water quickly.


These are the most inexpensive additives used in the potting mix for aeration. Sand can increase the weight of the container, so use it to maintain the proper ratio.

Use coarse sand, silica sand, or beach sand to mix your potting mix.


This is one of the essential 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 to the mix.

Water-Holding Gels:

Using water-holding gels in the potting mix is becoming popular daily for 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 the 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 sound drainage system
  • Proper aeration of 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 mainly differ on the soil quality.

  • The standard potting mix is 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 combinations mainly fulfill the demand for a good potting mix.
  • There have different branded commercial mixes also available in local and online stores. Choose the right one, and compare it to the criteria of a good potting mix.

Which Soil Combination is Suitable for Growing Tomatoes on the Rooftop?

The lightweight potting soil mix is best for growing tomatoes on 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, you should sterilize your garden soil before growing tomatoes.

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

You could skip this step if you didn’t grow any nightshade-type plants like eggplants, pepper, potatoes, or tomatoes in your backyard.

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


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. Instead, 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 to your tomatoes. It will fulfill your gardening goal.

So make 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.

Leave a Reply

Your email address will not be published. Required fields are marked *