What Size Grow Bag for Tomatoes

A grow bag – or growth bag – is simply a container that your plant can live in. It can be made from many different materials, including plastic, paper and fiber. In terms of plants, the term “grow bag” refers to a container that is filled with soil and used for growing something other than vegetable plants.

There are two basic types of grow bags: air-pruned and self-watering. The air pruned bags use an internal plastic skeleton which the plant roots grow through as they spread out into the soil that you placed in the bottom of the bag. This allows better water and nutrient absorption because there is more surface area in the roots.

What Size Grow Bag for Tomatoes?

You will need a minimum of 10 gallons for a tomato plant, but the optimal size can vary by region and you should consult the specific requirements of your tomato variety to determine what will work best.

 How to Calculate the right Grow Bag Size for Tomatoes

I am going to provide a few simple instructions on how to figure out what size grow bag you need for your tomatoes, and also some of the most popular sizes available.

1) Take 3 measurements: height, width, depth. Height would be from top of the plant’s roots to the point where you are measuring (typically an inch or two; wherever space is limited), width would be from left-to-right and depth from front-to-back.

2) Assume tomatoes are going to need 2-3 square feet:

5 Gallon = 12″x12″x30″ (diameter x height x depth). 10 Gallon = 12″x12″x38.5″. 15 Gallon = 12.5″x12.5″x45″. 20 gallon = 16″x16″x50″. 30 gallon = 18.75″x18.75″42″. 40 or 55 gallon – 24″×24″×50″.

3) If you do not have a tape measure and are shopping online, consider purchasing one from Amazon.com so you can guarantee the right size when buying your grow bag.

4) If your grow bag says 6″ diameter, but the description does not include a height and you are unsure if it will work for what you need.

5) If your plant is on the taller side (6 feet or more), consider using more than one grow bag – even two or three (or four!). Make sure you add the height of all grow bags together and purchase accordingly.

Why Should You Use Tomato Grow Bags?

Why should you consider growing your tomatoes in a grow pot in the first place? We’ve already mentioned the benefits of grow bags in situations where there are space constraints. Grow bags are the perfect option for confined spaces, apartments, and condos.

Grow bags are also used on plantations where the soil in the area is not ideal for growing tomatoes. Instead of planting in the soil, they use grow bags instead.

When it comes to confined spaces, grow bags have an advantage over pots, for example, because they deal with root balling. When a plant is in a pot, the roots eventually reach the wall of the pot. When they do, they keep growing in a spiral manner around the pot, and this known as root balling.

When the plant root reach the walls of a grow bag, they are exposed to oxygen and end up dying and drying off. This allows for the development of a stronger central root system which bodes well for the plant.

Grow pots are also a lot cheaper than regular pots and have great drainage meaning you will root rot. They also have the advantage of being able to suck water up from the bottom.

It’s great for when you travel for a number of days and are not able to water them. Simply sit them in a water bath about a quarter of the way up and your plant will be watered from the bottom up while you are away.

What is the best grow bag for tomatoes?

The bags that will produce the most tomatoes are assuming you follow the grow bag instructions above and have a tomato plant that stays healthy for your region.

Grow Bags vs. Soil

Grow bags are easier to plant in, maintain and clean up. A grow bag provides a stable root system – making it easier to produce fruit, because it is contained in a contained space.

It is both easier and more convenient than having to spread some soil out on the ground or create your own bed. It is more convenient than having to add compost into your soil each year and trying to make sure it is the right amount. We have found that a grow bag does not need any additional additives besides an occasional dose of nutrients (either from our recommended fertilizer or fish emulsion).

In addition, the soil in a grow bag retains moisture better than soil in beets and weeding is easier with a grow bag as well. Quite simply, you will see bigger tomatoes and fruit with flower clusters that are larger, healthier and more robust because the plant has been contained overall with less upkeep.

Are grow bags good for tomatoes?

That all depends on the grow bag and how you use it. We have found that a grow bag should be used as follows:

1) It is best for plants in small container gardens (and yes, tomatoes are a plant of the nightshade family), berry vines, herbs, or flowers.

2) If your tomatoes are still young (no taller than 6″), then no – you do not need a grow bag. A tomato plant in a properly sized planter box will work just fine. Grow bags for tomatoes become necessary when they are taller than 6″ – and sometimes even sooner.

3) If you are growing more than one tomato plant, we recommend using a grow bag for each – as opposed to the same size container. Otherwise, the plants will compete with each other for resources and it will hinder the overall growth of both plants.

4) If you are growing in a grow bag and have a tomato plant that is taller than 6″, it is possible to tie your tomato to another tomato or some kind of support system (like a stake or old rake handle you’ve bent into an arch). This will help keep your plant healthier (and safer) because the weight of the fruit will not be pulling down towards the center of gravity. It also increases yield by maximizing space and light exposure.

How to Plant Tomatoes in a Grow Bag

Planting tomatoes in a grow bag is an easy process. All you will need for this process is the grow bag (we recommend using 2-3 bags per plant), some good potting soil, a tomato plant, and some gardening tools. You will also want to purchase our recommended fertilizer to ensure your tomato plant is healthy and strong.

Step 1: Preparing Your Grow Bag

First, make sure that the grow bag has been sealed right before use. It should not be wet – but it should not be totally dry either. It should feel about the same as a damp sponge. It is also a good idea to mist the grow bag before you put your tomato in it so it will not dry out. You can spread some seeds or chicken manure on the bottom (about 3 inches) to provide nutrients for your plant and aid with drainage.

Step 2: Add Your Planting Mix

You will want to fill the grow bag about half full with planting mix – enough to add up to 8 inches of soil above the plants. It is best to buy organically-grown, sterilized potting soil from your local nursery or garden center. If you do not have access to a decent supply of potting soil, you can purchase the Miracle-Gro All Purpose Potting Mix and add a heaping handful of compost or composted manure at the bottom for fertilizer and drainage.

Step 3: Plant Your Tomato with a Grow Bag

Now that your grow bag is prepared you are ready to add your plant. Make sure this tomato plant is healthy – it should ideally be taken from another location – and look healthy.

Also make sure that it has been in sunlight for about 12 hours prior to transplanting so it will be able to get accustomed to its new home quickly. Your tomato should have some of its leaves intact. If it doesn’t, that is okay – but try to make sure that the plant is at least 3-4 inches tall and has some root growth.

Step 4: Watering Your Tomatoes with a Grow Bag

When you first transplant your tomato plant, it will need about 1 inch of water each week. Make sure you are not over-watering or under-watering the plant – you should be using enough water to ensure it has proper drainage, but not so much that it is sitting in a puddle of water.

Step 5: Feeding Your Tomatoes with a Grow Bag

Your tomatoes will require some additional fertilizer when they are about 3 to 4 feet tall. You will want to apply approximately 1/4 cup of water-soluble fertilizer. Do this every two weeks and continue until the plants are about 5 to 6 feet tall. At this point, you can stop fertilizing.

Step 6: Watering Your Tomatoes with a Grow Bag

Once your tomatoes start producing flowers, you will want to make sure you are watering them every day. This will ensure a good fruit set and quality. You can water lightly twice per day if needed. Be sure that the soil is kept moist but not soggy or sitting in a puddle of water.

Step 7: Harvesting Your Tomatoes with a Grow Bag

Your tomatoes can be harvested at any time once they are ready to cut from the plant.