Pot size for tomatoes | 5 to 20 Gallons

The best pot size for patio tomatoes is 14 inches wide and 12 inches deep. Larger tomatoes like Cherry will need a 16 inch wide by an 18 inch deep pot. For the largest tomatoes like Black Russian will grow best if planted in a 20 x 18 inch pot. Use good quality potting soil when growing tomatoes in pots for the best result and delicious tomatoes.

Pot size for tomatoes

Tomato TypePot WidthPot DepthCubic Inches*Pot size in Gallons
Patio14 inches12 inches13705.9
Cherry Tomato16 inches18 inches243210.5
Beefsteak16 inches18 inches243210.5
Grosse Lisse20 inches18 inches329914.3
Black Russian20 inches18 inches329914.3

*assumes a 10 inch base

What size fabric pot to use for tomatoes

Fabric Pot SizeNumber of tomato plantsNumber of tomato plants
5 GallonPatio Tomato1
10 GallonCherry Tomato or Beefsteak1
25 GallonGrosse Lisse or Black Russian1
30 GallonCherry Tomatoes or
Beefsteak or
Grosse Lisse
Black Russian

What size pot to use for cherry tomatoes

Cherry tomatoes will grow well in a pot that is at least 16 inches wide and 18 inches deep or around 10 Gallons. This will give the cherry tomato to enough room to grow a strong root system and enough surface area for small feeder roots to absorb nutrients from the soil.

Choose a larger pot or grow bag that is at least 20 gallons or 32 inches wide if you want to plant 2 cherry tomatoes. These will produce enough tomatoes for a small family over the growing season

My cherry tomato plant is growing nicely over winter in a sub-tropical climate.

What size pot to use for Beefsteak tomatoes

Plant Beefsteak tomatoes in a pot at least 16 inches wide and 18 inches deep or 10.5 gallons for the best results. Use a good quality potting mix to provide slow release fertilizer and to hold moisture well. Place a stake or tomato cage in the pot at the time of planting to support the plant.

Using a pot that is at least 16 inches wide will allow the space to put a tomato cage.

The pots below from Amazon will fit a Beefsteak tomato and cage on top to support. Click on the image for more info.

A tomato cage will help to support Beefsteak tomatoes that can grow up to 4 feet high and 3 feet wide. Click on the image below to check out this one from Amazon.

Best size pot for tomatoes in a greenhouse

To grow tomatoes in a greenhouse successfully the minimum pot width for tomatoes is around 14 inches. If tomatoes are grown in smaller pots this can limit their root growth and will not reach their maximum size without lots of liquid fertilizer.

Depending on the width of your shelving in your greenhouse, you can use standard garden center pots. It is best to plant out tomato seedlings into the pot that they will ultimately grow in rather than moving them once they grow.

Once tomatoes have been planted out, they will grow better if they are not moved again and their roots are not disturbed.

How to stake tomatoes in pots

Tomatoes including Black Russian, Grosse Lisse and Beefsteak will all require support from a stake or tomato cage. The easiest way to support tall growing tomatoes is to place a hardwood or bamboo stake in the pot before planting.

Step by guide to staking tomatoes in pots

  1. Choose a pot that is at least 14 inches wide.
  2. Fill the pot with good quality potting soil with a slow release fertilizer. Leave a 1 inch gap down from the top of the pot.
  3. Dig a hole in the soil the same size as the root ball of the tomato seedling.
  4. Place the tomato seedling in the hole and backfill with soil.
  5. Choose a stake that is at least 5 feet long and press it firmly into the soil next to the plant. Do not put the stake into the plant roots.
  6. Use a small tie to fix the plant to the stake as it grows.

Growing patio tomatoes in pots

Patio tomatoes are a small variety that has been bred to grow well in containers. They grow to around 2 feet tall and up to 2 feet wide. They can be kept smaller by pruning the tips of the stems.

Place a tomato cage over the top of the plant as it grows if the stems are being weighed down with the weight of tomatoes.

Patio tomatoes grown in pots can grow up to 50 tomatoes in one season and are great for a small space.

What to plant with tomatoes in a pot

Here is a list of the best plants to grow with your tomato in a pot.

  • Marigolds
  • Basil
  • Parsley
  • Chives
  • Nasturtiums
  • Borage
Last seasons basil is growing tall next to my cherry tomato plant.

If you have chosen a smaller pot it is best to grow the tomato on its own so that it has full access to all of the soil, water and nutrients it needs.

Choose a larger pot if you would like to companion plant with delicious herbs like basil or parsley. Plant tomatoes with flowering plants like Marigolds and Nasturtiums to attract pollinating insects to produce more tomatoes on your plants.

What soil to use for tomatoes in pots

Use a good quality potting soil that is made for vegetables as this will contain a wide range of nutrients that will feed your tomatoes for around 3 months. Tomatoes are hungry plants so add in extra compost, worm castings or aged cow manure to boost the soil mix.

This will help the plant to stay moist

What fertilizer to use for tomatoes in pots

Use organic liquid fertilizer like fish emulsion on your tomatoes every 4 weeks during the growing season. Stop adding liquid fertilizer when you see the first flower buds.

Alternatively add 1 handful of pelleted chicken manure at the time of planting and 1 handful 4 weeks later. This will give your plant a slow, drip feed of nutrients when you water.

Pelleted chicken manure is great for tomatoes in pots.

Best mulch for tomatoes in pots

Straw, sugar cane or hay are the best mulch types to use for tomatoes grown in pots. After planting, place a 1 inch layer of mulch over the top of the soil to keep soil moisture in and prevent soil from splashing onto the plant stems and leaves.

Using mulch in tomato pots can help prevent diseases and mold forming on the leaves from water and soil splashing up when watering.

Sugar cane mulch is a great light mulch for tomato plants in pots.

Pot size for tomatoes – Summary

Choosing a pot that is big enough for your tomato to grow to full size will give your plant the best chance to produce its maximum tomato yield. If you plant into a smaller pot, you can still have success but you may not reach the full potential of your tomato.

Keep your tomatoes well watered when planting in pots because they will dry out quicker than those planted in the ground. Dark colored pots can heat up in the sun so on very hot days, surround your tomato with other pots to shade it and keep the soil cooler.

Happy gardening.

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