The best potting soil or mix for tomatoes

The bag must say either potting soil or potting mix, these terms are interchangeable. How to use these potting soils/potting mixes in each type of planting application such as pots, containers, raised beds, regular backyard dirt, etc. will be explained in each of those separate articles.

As you know I suggest specifics. Now we are talking brands of potting soil/mixes. Whether you are planting in a container, a raised bed, or a backyard type garden I suggest using store bought potting soils/potting mixes that have sphagnum peat moss or peat moss listed as the No. 1 ingredient. Go to ingredients on the bag and see what is listed first.

Why is it important to use these specific potting soils? They have valuable water holding abilities. Soil with sphagnum peat moss as the No. 1 ingredient can hold up to 25 pounds of water. Soil with peat moss as the No. 1 ingredient holds almost the same. These potting soils/mixes cost a little more and in return you will not need to water as often.


Your soil looks and stays moist/wet all the way to top and all the way down the sides. Holds water around your roots like a sponge. With good soil you may need to water every 3-4 days compared to probably daily with cheap soil. Roots die when soil is dry. Less roots, smaller top, smaller top, less tomatoes.

Cheap potting mixes/potting soils that do not have the No. 1 ingredient as sphagnum peat moss or peat moss will have listed as the No. 1 ingredient something like contains “processed forest products” or “recycled forest products.”

So, what is that? This is like ground up brush and tree branches. Yes, left over forest type products. Yes, much cheaper to fill your bag with ground up tree branches than sphagnum peat moss or peat moss for sure. And this cheap soil dries out rather quickly. To keep these cheap soils moist you may need to water daily. As we said, when the soil is dry, the roots in that area will die.

Small root zone because of dry soil results in a small top and less fruit. Do you want to be known as the “Bonsai” tomato person? Your full grown tomato plant only a foot or two tall because of very small root systems, yes “Bonsai” tomato plants. Hahaha. So make sure to use a 20-25 gallon size pot or dig that hole big and fill it or your raised bed with great potting soil.

We want a big massive root zones which produce a big top and with a big top we get lots of tomatoes/fruit. This applies for most all vegetables except succulents. For example, dragon fruit/cactus will not want a lot of water.

Your biggest improvement this season will most likely be in using great potting soil/potting mix containing sphagnum peat moss or peat moss as the No. 1 ingredient listed on the bag. A little more expensive but you do not toss the old potting soil/potting mix out after each season. Reuse the old potting soil each year, just add new on top. The potting soil/mix will rot and decompose and next season you will simply add new potting soil/potting mix on top of the old.

Should you ever feel your potting soil/potting mix contains disease simply replace with new otherwise keep adding new on top the old as needed.

My brand recommendations:

  • “Organic Choice” found in Costco during spring is my overall top choice because it’s a great product that works and is about half the price of the others. Stock up.
  • G&B Organics Blue Ribbon made by Kellogg's is found year-round in nurseries and big box stores.
  • For those not concerned about organics, the Miracle-Gro blue bag is a great product. It's available at big box stores like Home Depot and Lowe's but is almost double the price of Costco soil.

🍅 Bumper Harvests Made Simple - Discover the secrets to cultivating tomato plants that yield over 100 lbs of fruit!

Expert Advice At Your Fingertips - Get straight-to-the-point guidance on tomato care, including:

  • Pest Control: Keep your tomatoes safe from critters.
  • Disease Prevention: Spot signs early and take action.
  • Optimal Growth Tips: Watering, sunlight, soil, and more!

A quick review!!! We want the No. 1 ingredient of potting soil/mix to be sphagnum peat moss and/or peat moss because?

Yes, it holds lots of water and acts like a sponge around the roots of your plants and you don’t need to water as often.

General definitions of soil ingredients on labels

Sphagnum peat moss and peat moss both have great water holding capabilities and aerate soil very well. Sphagnum peat moss is a partially decomposed sphagnum moss collected from bogs alive and then dried after harvesting. Peat moss is harvested from peat bogs. Many of these bogs are found in wetland areas of Canada.

Coir is the hairy part of coconuts, natural fiber extracted from the outer husk of coconut. One pound of of coir can hold up to about seven to eight pounds of water.

Perlite is like rock popcorn, or steam-expanded rock foam. Allows excess water to easily drain away and aerate the soil while retaining a little moisture and catching nutrients that plants need to grow.

You are welcome to share this information with others—family, friends and clubs, etc. Sharing tips helps us be better growers.

Sharing tips helps us be better growers.

Dave Freed /  the Tomato Guy