How to Grow Tomatoes in Pots

Growing tomatoes in pots is a fantastic option for those with limited space or who prefer container gardening.

I've learned that choosing the right pot and potting mix, placing the plants in an optimal location with adequate sunlight, and providing proper care and attention to watering and temperature needs are crucial factors in ensuring a healthy and fruitful tomato crop.

In this article, I will share my insights and knowledge on growing tomatoes in pots, so you can enjoy the delicious rewards of your homegrown tomatoes.

Selecting Suitable Pots

One main factor to consider when selecting what pots to grow your tomatoes in is size. Tomatoes grow into large plants with extensive root systems, so they need large pots. They will grow in smaller pots, but the more you scrimp on the size, the smaller the plant will be, and with that, your harvests will also be reduced.

I like to use these fabric pots. They are large, cheap and can be folded away over winter, so they take up very little room when not in use.

The fabric is also meant to air prune the roots to aid growth, but how effective this is, I am unsure.

You can also use many reclaimed pots to grow tomatoes and save money. Buckets and tubs are perfectly fine as long as they are large enough. You can grow tomatoes if it can hold soil and allow the water to drain away. Look at these below growing in reclaimed plastic tubs, for example.

Whatever you grow in, make sure it is a decent size; for round pots, look for ones that are 30cm in diameter or above and at least 30cm deep.

Preparing the Soil

Getting a good soil mix is crucial for a successful harvest. I use one mix for anything growing in containers: compost, 6x chicken manure and vermiculite.

The Chicken manure adds plenty of organic feed into the soil to help your plants grow. The vermiculite is added as it acts like a sponge, soaking water up. This is then released back slowly over time, which means your soil holds onto more water, meaning you shouldn't have to water as often.

If you don't fancy using chicken manure, then other slow-release feeds, such as fish blood and bone, work just as well. Chicken manure does have a smell for the first few days, so isn't suitable for indoor growing.

Growing Tomatoes From Seed

I like to start my tomatoes indoors under grow lights in spring before moving them outside or into the greenhouse later.

Later in spring, you can also use a sunny windowsill, but early in the year, even the sunniest windowsill doesn't get enough sun for healthy plants.

Use a module tray or seed tray and sow your tomato seeds. Cover with a thin layer of compost, then place them somewhere nice and warm to germinate. A propagator is best, but it is not essential; tomatoes will germinate just fine without one.

Spacing

It's important to provide enough space for the seedlings, as overcrowded plants can lead to reduced air circulation and increased risk of diseases. They will also suffer from stunted growth as they all compete with each other for nutrients.

Leggy Seedlings

If your seedlings go leggy (long, thin and weak), then this is usually caused by inadequate light. The seedlings are growing long and thin, trying to reach for the light, thinking they are competing with taller plants.

I have a full article on this and how to fix it, which you can find here.

Transplanting

When it comes to translating your tomato seedlings, a key tip I've learned is to bury the seedlings a little deeper than the depth they were in their starter pots. Tomato plants have the unique ability to develop roots along the buried stem, which results in a stronger root system and sturdier plants.

This is particularly important for tomatoes grown in pots, as a healthy root system can help the plant thrive in limited space.

To achieve the proper depth, first, remove the lower sets of leaves, leaving only the top few sets. Dig a hole in the potting soil deep enough to accommodate the seedling, usually around 3-5 inches (7.5-12.5 cm) deep. Carefully insert the seedling into the hole, taking care not to damage the roots, and fill the hole with soil, gently patting it down around the base of the plant.

Providing Adequate Sunlight

Tomato plants typically require at least six to eight hours of direct sunlight daily for optimal growth and fruit development.

If needed, you can move the pots during the growing season to maintain the desired sun exposure. If growing indoors, you will need a sunny windowsill (preferably south-facing) or a conservatory to succeed.

Watering

One of the biggest issues you will face with growing tomatoes in pots is watering. In the middle of summer, tomatoes need constant watering, and this is only exacerbated by using pots. Ideally, you will want to water them daily.

If you don't stick to a watering schedule and let your plants regularly dry out, then you will suffer from blossom end rot, an all too common problem.

Watering Techniques

From my experience, it is best to water tomatoes in the morning so they have enough moisture to withstand hot or sunny days. When faced with exceptionally hot or windy days, it is advisable to water plants in the morning and late afternoon. Here are some tips for watering techniques:

• Water deeply, ensuring excess moisture runs out of the drainage holes, to promote better root development.
• Apply water directly to the soil, avoiding the leaves, to minimise the risk of blight and fungus.
• Check soil moisture by pressing a finger about an inch or two deep into the soil; water the plant if it feels dry to the touch.

Preventing Over-watering

While drying out is a big issue, overwatering can also cause problems all of its own, it is a delicate balancing act. Here are my top tips:

• Use a well-draining compost mix to improve drainage and provide extra nutrients.
• Ensure the plants are never sitting in water; tomatoes don't like overly wet soil - this will lead to root rot.
• Add a layer of mulch around your tomato plants, which will help retain moisture by keeping the soil cool and away from direct sunlight.

Staking and Support

Staking and support are crucial for tomatoes. This helps the plants to grow vertically, keeping them well-centred and stable as they start to bear fruit.

I start by selecting suitable stakes for my tomato plants. When growing in pots, I often use bamboo canes but tomato cages can also work well. Whether you need support or not will depend on the type of tomato you grow. There are vine tomatoes, which need support and bush tomatoes, which often don't.

As the plant grows, I fasten the vine to the stake with a loose tie (plant ribbon, twine or plant wire) about every 6 or 8 inches, making each tie 1 inch above a flowering stem. This prevents the fastener from cutting into the stem when it becomes weighed down with fruit.

In some cases, such as when using a shallow container or dealing with small tomato varieties, I may need to use two or three stakes to share the load and provide sufficient support for the plant.

Pruning and Maintenance

Removing Unwanted Shoots

This is only required on vining tomatoes; bush tomatoes don't need pruning.

Removing unwanted shoots, also known as suckers, helps the plant to channel its energy into producing fruits instead of excessive foliage. These suckers usually grow between the main stem and the branches. To remove them, I follow these simple steps:

1. Examine the plant carefully and identify the suckers below the first flower cluster.
2. For smaller suckers, I pinch them off gently with my fingers.
3. For larger suckers, I use a pair of clean and disinfected pruning shears, making sure to avoid harming the main vine or nearby leaves.

Pest and Disease Management

If you are growing outdoors then blight is going to be your main issue. This is a fungal issue that can wipe out your crop. It is more likely later in the year and a lot more common in some areas, do a quick Google search to see how bad your area is.

You can purchase more blight-resistant varieties but apart from this, there isn't too much you can do. Growing indoors or in a greenhouse usually avoids these issues as blight is spread via spores.

Other common pests are slugs (usually more of an issue with younger plants), caterpillars, aphids and red spider mites. Keep a look out for any signs of infestation and seek advice if you spot anything!

Good luck with your container toms! If you have any questions then please ask away in the comments below and I will do my best to answer them all.

Daniel