Best Potting Soil For Tomatoes And Top Growing Tips

Best Potting Soil For Tomatoes And Top Growing Tips

It’s no secret that I love to grow tomatoes in my garden during summer. There’s nothing quite like that taste of a homegrown tomato when you compare it to store-bought varieties.

Why Are Homegrown Tomatoes So Good?

Homegrown tomatoes have an intensity of flavor that you just don’t get when you purchase fruits that have been grown commercially. And, there’s a good reason for this.

When we grow delicious tomatoes at home, we generally let them ripen fully on the plant. This allows the sun to do its magic which helps to develop the sugars in the fruit. This, in turn, means that you end up with tomatoes that are sweet, juicy, tangy and full of flavor.

*This website is reader-support so this post may contain affiliate links for which I earn commissions.*

On the other hand, store-bought tomatoes are usually harvested well before they’re fully ripe. This is necessary in order to store them for long periods and stop them from getting damaged during transport and handling.

After being harvested, commercially produced tomatoes are put into cold storage in order to preserve them. Then, when they’re ready to go to market, they’re artificially ripened using ethylene-type gas.

So, now that you know why homegrown tomatoes taste so much better, you might be wondering whether you have room to grow them in your garden.

Depending on the variety that you’re growing, tomatoes can take up a fair amount of space. 

However, if you don’t have a suitable outdoor space to grow them, you can easily grow your tomatoes in pots.

Before we go into this further, let’s have a look at the type of soil that tomatoes like best.

What Kind Of Soil Do Tomatoes Prefer?

small tomato plants growing in rich soil

Tomatoes are heavy feeders. This means that they like soil that is rich in organic matter and nutrients. The soil should also be free-draining but not dry out too quickly because tomatoes are also quite thirsty plants. In general, nice loose soil is great for optimum growth in healthy tomato plants.

The soil should be slightly on the acidic side with an optimum soil pH level of between 5.8 and 7. Therefore, if you’re growing your tomatoes in the garden, you want to ensure that you enrich your soil with plenty of organic materials such as compost and aged manures.

Ideally, you want to make your own compost if you can as this gives you complete control over what goes into it. If you have enough space in your garden for a compost bin or compost tumbler, you might want to read my comprehensive article about how to make the best compost.

However, if you don’t have a reasonable outdoor garden area or you only have a very small space, you can easily grow luscious tomatoes in a large pot. Choose a determinate variety rather than indeterminate tomatoes if you can as these will generally be more compact.

If you visit your local garden centers, look out for varieties labeled as “Patio Tomatoes”. These will be the easiest to grow in a large pot.

Make sure that the pot you choose is at least 12 inches (30 cm) in diameter so that the roots of your plant have enough space to grow. This will give you the best results.

Once you decide to grow your tomatoes in containers, you’ll have to select the best potting soil that will allow your tomatoes to thrive and produce plenty of fruits.

Great Potting Mixes For Growing Lush Tomato Plants

Planting small tomato seedlings in premium potting soil

When selecting the best potting soil for your tomato plants, you have two choices. You can either purchase a good commercial mix that is designed for growing vegetables such as tomatoes or make your own with some prime ingredients.

Let’s first have a look at some of the better commercial potting mixes that I would consider for growing healthy tomatoes.

Important Note: Never ever fill your pots with common garden soil. Garden soils are generally too heavy and don’t have the perfect structure for pot-grown plants. They will suffer from soil compaction when used in containers and the plant roots of your tomatoes will not be able to grow well.

Best Commercial Potting Mix

To give you an idea of some really good commercial potting mixes that I could recommend, I did some research on Amazon to see what is readily available. I then carefully looked at the composition of the various mixes and also the N:P:K content.

For those who don’t know, the N:P:K content is a common ratio used in the horticultural industry to let you know how much Nitrogen (N), Phosphorus (P) and Potassium (K) is in the mix.

These three are the vital nutrients that you need to consider when choosing the right potting soil for your pot-grown plants. In saying that, different plants need different levels of each nutrient in order to grow well.

For tomatoes, which are fruiting plants, you want a mix that has a relatively even mix of phosphorus and potassium and only a slighter higher ratio of nitrogen. 

To put it simply, nitrogen is necessary for green growth such as leaves and stems. Phosphorus helps to grow a strong root system while potassium is necessary for good flowering and fruiting.

So, after taking a closer look at some of the commercial mixes that are readily available and carefully looking at the organic ingredients that they contain, here are my top picks.

Back To The Roots All-Purpose Potting Mix

Back To The Roots All-Purpose Potting Mix

This looks like the perfect mix for growing your tomatoes. It contains coco coir, earthworm castings and Yucca extract. It should be noted that when I look for premium potting mixes, I always look for ones that are peat-free.

This is because I understand the importance of protecting the naturally occurring peat bogs rather than harvesting the peat and watching them all dry up and release dangerous greenhouse gases in the process.

The other thing I like about this mix is that it contains mycorrhizae that are beneficial for root formation. 

The mix has an N:P:K ratio of 0.18:0.4:0.4. This is fairly adequate for growing tomatoes but I would definitely supplement this with additional organic fertilizer during the active growing period.

Wonder Soil Organic Potting Soil

Wonder Soil Organic Potting Soil

This is another good potting soil that is completely peat-free. It contains coco coir, worm castings, kelp and perlite. All these ingredients make up a fantastic potting mix for tomatoes. 

Another benefit is that this mix is compressed. This means that you have to add water which will expand the mix making it very economical for pot-grown plants.

I couldn’t find an exact NKP ratio for this mix but all major nutrients are below 1%, so you will need to add some fertilizer while your tomatoes are growing. A liquid fertilizer high in potassium once a week will be sufficient.

Organic Plant Magic Compressed Potting Soil

Organic Plant Magic Compressed Potting Soil

This is another compressed organic potting soil that contains only natural ingredients such as coconut coir, worm castings, rock phosphates and kelp. This product actually has a balanced N:P:K ratio of 1.0:1.0:1.0.

This means that it has equal amounts of the three main nutrients required for great plant growth. 

However, because tomatoes are heavy feeders, I would still supplement the tomatoes with a liquid feed once a week during their flowering and fruiting time.

Organic Mechanics Peat-Free Potting Soil

Organic Mechanics Peat-Free Potting Soil

This is another peat-free potting soil that I found. It contains coconut coir fiber, worm castings, compost, pine bark and rice hulls. What I particularly like about this mix is that it will retain moisture but is still free-draining. 

The N:P:K content of this mix is also fairly low, so you’ll have to add fertilizer for your tomatoes to produce lots of growth, flowers and fruits.

Best Homemade Potting Mix

filling a pot with homemade potting soil using a small trowel

You can also make your own potting soil for your tomatoes. This ensures that you have complete control over the contents of the mix and can use all-natural materials without having to resort to using mixes that contain any kind of peat moss.

My all-time favorite best soil mix is relatively simple to make, highly nutritious and great for optimum plant growth. I just like to combine homemade compost with coconut coir for a light and fluffy mix that has both water-holding capacity and plenty of nutrients to get the plants started.

Generally, I would mix two parts of compost with one part of coconut coir. I purchase the coconut coir in compressed bricks. Then, I place the brick into my garden cart and just add the required amount of water to make it expand.

If you don’t have the space to make your own compost, here’s another recipe for a good mix that you can make from purchased materials:

Use equal parts of coconut coir, builder’s sand and perlite and mix together. This will create a nice open mix that can hold enough moisture but still allow for good drainage.

With this type of mix, you will need to add in some fertilizer because it doesn’t contain any nutrients. You can purchase an organic slow-release fertilizer in pelleted form that you can just mix in while you’re making the potting soil.

If you find you have some homemade potting soil left over and won’t be using it straight away, just store it in a plastic container with a tight-fitting lid.  

Top Tips For Container Grown Tomatoes

Here are some of my top tips for growing tomatoes in containers:

  • Keep your plants well-watered and don’t let them dry out. Proper watering is essential for a healthy crop.
  • Feed your plants regularly – at least once a week if using a liquid feed such as fish emulsion
  • Sprinkle some wood ash on top of the soil as this is full of potassium and will promote more fruiting
  • Make sure that you place your potted tomatoes in a nice sunny spot
  • Remove some of the lower leaves once your plants start to grow taller
  • Make a potassium-rich liquid feed by steeping banana skins in water for around a week or two

Frequently Asked Questions

Do tomatoes prefer deep or wide pots?

The pot that you choose for your tomato plant should be both deep and wide. Select a pot that is at least 12 inches (30 cm) in diameter and of about the same depth.

What is the best fertilizer for tomatoes in pots?

To promote good fruiting, you should use a fertilizer that is high in potassium. There are plenty of proprietary fertilizers that are designed specifically for growing tomatoes.

What is the best mulch for container tomatoes?

For tomato plants in containers, I would use a thick straw mulch. This will help to keep more moisture in the soil.

Is Seasol good for tomato plants?

Standard Seasol is a soil conditioner and not a fertilizer. However, it is definitely beneficial for using on your tomato plants because it will promote strong and healthy growth.

How often do you water tomatoes?

Tomatoes grown in pots do need regular watering. During summer, they should be watered daily and if it’s really hot, they may need to be watered twice daily. Your tomato plants will wilt if they’re not receiving enough water.

Final Thoughts

Tomatoes are not that difficult to grow if you give them the right environment. Even if you don’t have enough outdoor garden space, you can still successfully grow tomatoes in pots. 

For optimum results, choose a large pot and a premium potting soil. Try to select one that is peat-free as this is better for the environment. Coconut coir is a good substitute for peat as it is a by-product of the coconut industry and is freely available.

You can also make your own quality potting soil at home. Especially if you like to make your own compost as well. This way your tomato plants will get the nutrients that they need right from the start.

Above all, make sure that you keep your pot-grown tomato plants well-watered and feed them regularly to ensure lots of growth and fruit production. Then, enjoy your harvest!

Leave a Reply

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

This site uses Akismet to reduce spam. Learn how your comment data is processed.