Growing Tomatoes in a Small Space: A Guide to Grow Bags & Pots

There’s something pretty special about picking a ripe, sun-warmed tomato straight from your own plant. And you don't need a big backyard to do it.

You don't need a large vegetable garden to enjoy a good harvest. With the right variety, a suitable container and a little attention to watering, you can grow productive tomato plants on a balcony, courtyard, patio or in even the smallest of gardens.

Tomatoes can grow surprisingly well in pots, containers and grow bags.  They're not particularly difficult, but choosing the right variety for your space and understanding what they need to thrive will make all the difference.

And when you grow your own, you get to choose the varieties you like the sound of – perhaps a sweet cherry tomato, an old-fashioned heirloom or a big beefsteak – rather than simply choosing what's available at the supermarket.

You can also leave your tomatoes on the plant until they're properly ripe and ready to eat. Pick one straight from the vine and you'll understand why growing your own is worth the effort! The taste, flavour and texture are completely different from store-bought tomatoes that have been picked unripe, transported and refrigerated.

The trick is to choose a tomato that suits the space you have and then give it enough sun, room for its roots, water, nutrients and something to support it as it grows.

Here are some of the things I've found most important when growing tomatoes in containers and grow bags.

When should you plant tomatoes in Australia?

Tomatoes are warm-season plants, so when you plant them depends on where you live.

omatoes are warm-season plants, so timing is important. Plant too early while the soil is still cold and growth can be slow. Plant too late in areas with hot summers and you may find the heat affects flowering and fruit production.

When to plant depends on where you live, your local climate and the conditions in your particular growing space.

As a general guide:

• Tropical and frost-free warm regions: Tomatoes can be grown at different times of the year, although it's often best to avoid the wettest periods and extreme summer heat. In some tropical areas, the cooler dry season is a better time to grow.

• Subtropical regions: Spring and autumn are often good planting opportunities. You may also be able to grow through winter in frost-free locations.

• Temperate regions: Spring is a popular time to plant, generally from August through to November, depending on local conditions.

• Cool and cold regions: Plant in spring once the risk of frost has passed and the soil has warmed. September to November is a useful general guide, but colder inland areas may need to wait longer.

These are starting points rather than fixed dates. Your local conditions matter more than the calendar.

If you're unsure about the conditions in your garden, take a look at our blog, Know Your Small Space Garden Grow Zone. It will help you understand the growing conditions in your space and when to make the most of each planting season.

Choose a tomato that suits your space

Not all tomato plants grow in the same way, and this is worth thinking about before you buy your seedlings.

Tomatoes are generally divided into two growth types: determinate and indeterminate.

Bush or determinate tomatoes stay relatively compact and are often easier to manage in pots and smaller spaces. They tend to produce their crop over a shorter period and finish their growing cycle.. they are often called bush or patio tomatoes because they are an excellent choice for smaller containers, balconies and courtyards.

Indeterminate  keep growing and producing fruit over a longer period when conditions are favourable. They can be wonderfully productive, but they need more room and a good support.

Some climbing tomatoes can easily grow well over a metre, and some will grow considerably taller than that. If you're growing one on a balcony, make sure you've thought about where it's going to go!

If space is really limited, look for words such as bush, dwarf, patio or determinate on the plant label or seed packet.

Cherry tomatoes can also be a good choice for smaller gardens. Many varieties are very productive, and because the fruit is small, you don't have to wait for one enormous tomato to ripen before you start harvesting.

Some tomato growers suggest planting herbs or other plants in the same container. I would recommend refraining from adding additional plants to the container unless it is a large container with a lot of space around the centrally planted Tomato. You do not want other plants competing with the tomato plant for water or nutrients. Different tomato varieties require different spacing, so consult the seed packet or tag on your tomato plant for information.

Cherry tomatoes are another popular choice for smaller gardens, but don't assume every cherry tomato plant will be compact. Some varieties grow into quite substantial vines, so check the plant label or seed packet before choosing.

If space is limited, look for dwarf, bush or patio varieties. These are often easier to manage in containers.

Choosing the right grow bag size for your tomatoes

The size of your container is one of the most important decisions you'll make. Tomatoes develop an extensive root system and need enough room to access the water and nutrients required to support healthy growth and fruit production.

A container that's too small can dry out quickly, leaving you with a plant that needs constant attention, particularly during warmer weather.

When choosing a Root Pouch grow bag, consider both the eventual size of the plant and the amount of space you have available.

Determinate Tomatoes (Bush or Dwarf)  - we recommend 16L to 56L Root Pouch grow bag

Indetermintae Tomatoes - we recommend from 78 L upwards to our smaller Raised Garden beds. Keep in mind, the reason for starting the recommendation at the 78L bag is to allow room for trellising or stakes to support the tall plant)

As a general rule, I'd rather give a tomato plant a little more room than try to squeeze it into a container that's too small. A larger volume of growing medium gives the roots more room to develop and can help maintain more consistent moisture.

Remember that the size of the plant matters too. A compact bush tomato has different requirements from a vigorous climbing variety that will continue growing and producing fruit throughout the season.

Root Pouch grow bags are particularly useful when you're short on garden space. They're lightweight, easy to position and provide a breathable growing environment for healthy root development. Their fabric construction allows air to reach the roots, encouraging air pruning rather than the circling roots that can occur in some solid-sided containers.

Good drainage is equally important. Tomatoes like consistent moisture, but their roots need access to air and shouldn't be left sitting in waterlogged growing medium.

Incorporating a Waterpot Olla into your grow bag

One of the things I particularly like about growing tomatoes in a Root Pouch grow bag is the ability to incorporate a Waterpot Olla directly into the growing medium.

If you're not familiar with ollas, they're simple terracotta watering vessels that have been used for centuries to help irrigate plants. Their porous terracotta walls allow water to seep gradually into the surrounding growing medium as the soil dries.

Rather than applying all your water at the surface, an olla makes moisture available closer to the root zone, where your tomato plant can access it.

This is particularly useful for tomatoes because they need a reasonably consistent supply of moisture, especially when they're flowering and developing fruit.

When setting up your grow bag, position the olla in the growing medium before planting your tomato. This makes it much easier to get everything in place without disturbing the roots later.

A few things to consider when incorporating an olla:

• Choose an appropriate size: The olla needs to be suited to the volume of growing medium in your bag and the water requirements of your plant. 

  16L to 56L Root Pouch grow bag - We  recommend the Waterpot Tall Olla Olla

  78 L upwards to our smaller Raised Garden beds -  Keep in mind, the amount of trellising or stakes you need for your plant when looking at the size of Waterpot Olla to use.  Any grow bag from 78 upwards can accomodate a  3L Waterpot Large Round Olla or 6L Extra Large Olla  trellising or stakes to support the tall plant). The Waterpot Tall Olla can also be used but the smaller volume of water in the !L vessel will require more frequent refilling.

• Position it carefully: Place it so that the porous terracotta is surrounded by growing medium, with the "shoulders" just covered, leaving the neck exposed,

• Allow room for the roots: Position it before planting, taking care not to damage the seedling's root system.

• Keep an eye on moisture: An olla helps maintain moisture around the root zone, but it doesn't mean you can forget about watering altogether. Check your plants regularly, particularly during hot and windy weather, when they may need additional water.

Combining a generously sized Root Pouch grow bag with a Waterpot Olla gives you a practical way to manage moisture while providing plenty of room for your tomato plant to grow.

Plant your tomato deeper 

Tomatoes have a useful trick that many other plants don't. They can develop additional roots along the stem where it is buried in the growing mix. When planting tomato seedlings, you can encourage a stronger root system by planting them a little deeper than they were growing in their original pot.

Remove the lower leaves and bury part of the stem in the growing medium. Tomatoes have the ability to develop additional roots along buried sections of stem, helping establish a more extensive root system.

Take care not to bury the leaves themselves, and avoid this technique with grafted tomato plants, where the graft union needs to remain above the growing medium.

Water the seedling in well after planting and allow it time to establish.

Give your tomato plant some support

A tomato plant might look small and harmless when you first bring it home. Give it a few months and it can be a completely different story!

Once the plant is carrying fruit, the branches can become surprisingly heavy.

If you're growing an indeterminate tomato, you'll need to provide support as it grows. Even some of the smaller bush varieties benefit from a little support once they're carrying a good crop of fruit.

It's best to put your stakes or climbing frame in place when planting. Trying to push supports into the growing medium once the plant is established can damage the roots.

As the plant grows, gently tie the stems to the support using soft garden ties or strips of fabric. Avoid tying them too tightly, as you don't want to restrict the stems as they thicken.

If you're growing in a small space, consider the height and spread of your support structure before you plant. You want to make the most of your available vertical space without allowing the plant to become overcrowded.

Sunlight and heat requirements

Tomatoes love sunshine, but there's a difference between giving them enough light and exposing them to excessive heat.

Aim for at least six hours of direct sunlight a day, with around seven to eight hours being ideal in many growing conditions. One of the great advantages of growing in containers is that you can move your plants if their position isn't quite right. A balcony or courtyard that receives morning sun, for example, may be more suitable than a position exposed to intense afternoon heat.

In Australian summers, this is particularly worth considering. Extended periods of very hot weather can affect flowering and pollination, while intense sunlight can scorch exposed fruit.

If temperatures are forecast to climb, a little afternoon protection can help reduce stress. Avoid removing too many leaves when pruning, as the foliage also provides valuable shade for developing tomatoes.

The aim is to give your plants plenty of light without allowing them to become stressed by extreme heat.

Keep your tomato fed

Tomatoes need a steady supply of nutrients to support their growth, flowering and fruit production. They're particularly hungry once they start producing fruit.

Start with a good-quality potting mix suitable for vegetables and containers. Check whether it contains a starter fertiliser and follow the manufacturer's instructions.

As the plant develops, use a fertiliser formulated for tomatoes or fruiting vegetables. Follow the recommended application rates, as too much fertiliser, particularly nitrogen, can encourage lots of leafy growth at the expense of flowers and fruit.

Plants growing in containers generally need more regular feeding than those growing in the ground because nutrients are gradually used up or washed through the growing medium when watering.

A regular feeding routine, adjusted to the fertiliser you're using, will help keep your plants productive throughout the season.

Watering consistently

Getting the watering right is probably one of the biggest challenges when growing tomatoes in containers.

Tomatoes need a consistent supply of moisture, particularly when they're flowering and developing fruit. Allowing the growing medium to become very dry before giving the plant a heavy watering can cause problems.

Inconsistent watering can contribute to fruit splitting and blossom-end rot. It can also put the plant under unnecessary stress, particularly during hot weather.

Root Pouch grow bags have breathable fabric sides, which are beneficial for root health but also mean moisture can be lost through the sides of the bag. This is why it's important to keep an eye on moisture levels, particularly during summer.

Water deeply enough to reach the root zone, rather than simply wetting the surface. Mulching the top of the growing medium can also help reduce moisture loss.

This is where incorporating a Waterpot Olla can make a real difference. By gradually releasing water into the surrounding growing medium, it helps provide moisture closer to the roots and reduces reliance on frequent surface watering.

You'll still need to check your plants and refill the olla as required. Think of it as a useful part of your watering routine rather than a complete replacement for watering.

What causes blossom-end rot?

If you've ever grown tomatoes before, you may have seen a dark, sunken patch develop on the bottom of a tomato. This is called blossom-end rot.

Despite the name, it's not a disease.

Blossom-end rot is associated with insufficient calcium reaching the developing fruit. However, this doesn't necessarily mean there's not enough calcium in the growing medium. Calcium is transported through the plant with water, and when moisture levels fluctuate, the plant can struggle to deliver enough calcium to the developing fruit.

This is why inconsistent watering is such a common contributing factor.

To help prevent it:

• Maintain reasonably consistent moisture in the growing medium.

• Avoid allowing the plant to dry out completely, particularly when fruit is developing.

• Don't overdo nitrogen fertiliser, as excessive leafy growth can contribute to the problem.

• Make sure the growing medium is suitable and has an appropriate nutrient balance.

• Protect plants from excessive heat and stress.

Other factors can play a part too, so simply adding calcium isn't always the answer.

The first thing I'd look at is your watering.

A layer of mulch over the growing mix can also help slow down moisture loss during hot weather.

Enjoy growing your own tomatoes

You really don't need a large garden to enjoy homegrown tomatoes. A sunny balcony, a small courtyard or even a few well-positioned grow bags can provide plenty of opportunity to grow your own.

Choose a variety that suits your space, give the roots enough room, provide support where needed and pay attention to watering and feeding.

If you're growing in containers, a Root Pouch grow bag combined with a Waterpot Olla is a particularly practical way to get started. You have room for healthy root development and a simple way to help maintain moisture around the roots.

And perhaps the best part? Once you start picking your own tomatoes, you'll wonder why you didn't try it sooner!

Happy growing!

🍅KEY REMINDERS🍅

Whilst th list above seems like a long one of things one must remember to do or not do...here's a quick summary to make it easy peasy - 

☀️ Give it sunshine – aim for at least six hours of full sun.

🍅 Choose the right variety – bush and dwarf varieties can be easier when space is limited.

🪴 Give the roots room – don't put a vigorous tomato into a tiny pot.

💧 Keep the moisture consistent – especially when the plant is flowering and fruiting.

🌱 Feed it as it grows – tomatoes need plenty of nutrients to keep producing.

🪵 Provide support – don't wait until the plant is falling over under the weight of its fruit.

🌿 Give it some breathing room – good airflow around the plant can help reduce fungal problems.

Take a look at our Root Pouch grow bags and Waterpot Ollas – two simple ways to make growing tomatoes in a small space easier.

Happy growing! 🌱