How to grow delicious tomatoes in pots this summer

Last updated on January 26th, 2022

Growing tomatoes in pots

There is nothing more satisfying than growing your own juicy tomatoes. Experiencing the enjoyment of being able to eat your own freshly picked tomatoes that always seems to taste better than the ones you’ve purchased from a supermarket.

What’s more, tomatoes are one of the easiest and simplest edible plants to grow. They grow very well in pots and there are so many varieties you can choose from. Ranging from the cherry tomatoes of ‘Tumbler’ that trail beautifully over pots and planters to old favourites like the ‘Moneymaker’ and ‘Shirley’.

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The best way to grow tomatoes

Growing tomatoes in pots are probably one of the best ways to grow tomatoes. Nearly anyone can grow them, even if you do not have a garden or if you have a smaller house or apartment. They can be easily grown in conservatories, on a porch and on a small balcony. There is even a variety called ‘Balconi Red’ which has been named after the ideal place to grow them. Other places to grow them include windowsills in the kitchen and of course a greenhouse or on the patio in the garden.

Wherever you choose to plant them, they need as much sunlight as possible, ideally at least 5-7 hours a day to be really successful. The advantage of growing them in pots is that they can be moved if necessary to a sunnier position.

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When to plant tomatoes

Tomatoes can be grown from seed, purchased as small plug plants/seedlings or as small established plants in 9cm and 1 litre pots. The easiest way to grow them is probably by purchasing them already growing with a good root system in 9cm pots or larger. These plants can be planted straight into their final pots.

You can learn more about growing tomatoes from seed in this guide here.

If you purchase them as plug plants you can usually buy packs of 3 or 6 plants for a few pounds from online nurseries and have them delivered directly to your door. You often get really good value for money getting them this way, however, they will need to be grown on in larger 9cm – 1 litres pots before being transplanted to their final pots.

If you want to grow them from seed, then we would recommend growing them in jiffy 7’s, these are small peat plugs that swell up when soaked in water, and then you can plant one seed in each jiffy 7. Ideally, you would then place them in a propagator with heating underneath. They usually take around 7-14 days to germinate at a temperature of around 21C (70F) but this varies depending on the variety and the time of year. The later you sow them, the quicker they germinate as they have more daylight hours. Once they have enough roots they can be potted on, being careful not to damage the stems by holding them by the leaves.

The best time of year to plant tomatoes

• Sow seeds from March to April onwards, the aim is to sow them 7-8 weeks before the final frosts.
• Plant purchased plug plants or larger plants from April-May onwards.

Choosing a pot to grow your tomatoes in

Tomato plants are hungry plants and greatly benefit from being in large pots. One thing a lot of gardeners are not aware of is that it has been proven that tomatoes grow better when they get more oxygen to their roots through the soil.

First off, you will need to choose the right size pot. For smaller growing varieties (including dwarf and cherry tomatoes) that grow as a bush or vine grow well in around a 6 litre pot. These varieties include Balconi Red (dwarf), Tumbler (bush) and the very popular Gardeners Delight.

Larger tomatoes, such as ‘Roma’ and ‘Big Boy’ need to be planted in larger pots that are around 10 or 12 litres.

For the best results, it is recommended that you use a pot with small holes in it because this will help oxygen get to the roots. You can buy special air pots online or from garden centres that have holes specially designed for this, however, you can also just drill some small holes into the side of the pot. Make sure you don’t drill the holes too big because you don’t want the soil to fall out.

If you don’t want to drill holes into your pot because it is a decorative pot, then you can get a simple plastic-type and drill holes in the tub and then insert this into the pot before filling with soil.

We have also reviewed some tomato planters that are specially designed to keep tomatoes hydrated and you can read our comparison here. I have reviewed 4 of the best tomato planters.

What compost to use

Preferably, you want to purchase the best compost you can, compost with feed in is ideal. Some composts have long term six month fertiliser granules in. Some nurseries have their own mix you can buy so it is always worth asking about their own compost because it is usually better and worth the extra premium you might pay.

To help improve drainage and help air get into the compost we recommend mixing around 20% perlite with the compost and mixing it well.

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Tomato plant care

Watering tomatoes

This is probably the most important step when growing tomatoes. Get this wrong and you will be disappointed. The key here is to keep the compost moist, but not wet. You will probably find that they need watering every day, probably in the morning and sometimes even twice a day in very hot weather as the plants become established.

If they get too much water the roots may rot. Younger plants are more at risk because they are still establishing their roots. Too little or inconsistent watering can lead to blossom end rot, where the tomatoes turn black and the skins of the tomatoes crack.

Important Note – Inconsistent watering is probably the biggest reason for failed tomatoes!

Hardening off tomatoes

If you plan to grow your tomatoes outside in summer, then you need to harden them off first. For the first week, place the tomato plants outside during the day but bring them in at night, continue to do this until they seem happy to be outside. In general, when there is no risk of frost they can go outside for the rest of summer. This is often around the end of May to early June.

Feeding tomatoes

To be successful when growing tomatoes it is important to feed your tomatoes with a liquid feed around once every 10-14 days. Feed with any balanced fertiliser but as soon as they come into flower, or at the very latest once the fruit sets you will need to feed with a high potash feed. The easiest way to do this is to purchase a feed specifically designed for tomatoes which are usually one of the cheapest feeds anyway.

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Our 5 steps to successful tomatoes

1. Use large pots with air holes.
2. Use quality compost mixed with perlite.
3. Keep soil moist and do not allow them to dry out.
4. Place in a position where they get 5-7 hours of sun.
5. Feed with a high in potash tomato feed as soon as they flower.

Why not try growing trailing and bush tomatoes in hanging baskets, following my step by step guide.

You can even grow them upside down in special upside-down planters, which we looked at in this guide too.