8 Top Tips for Growing Tomatoes

Updated: May 16, 2021

tomato plants.

Tomatoes are a home-growing staple, there are so many varieties to choose from and their reward is delicious!

One of our team members, Sophie, decided to try growing tomatoes for the first time recently. She found some tomato plants being sold in her local neighbourhood and decided to give it a go! Having given her some top tips to look after her new tomato plants, I wanted to share this advice with you too, to help you on your own home growing journey!

There are so many reasons to start growing food from home. You’ll know exactly where your food has come from and it will be fresher and generally more nutritious than food that’s travelled a long way. Not only that, there really is a joy to growing your own food, it’s hard to describe the feeling of seeing something you have nurtured develop and thrive and eventually being able to taste the product of your efforts!

1. Tomatoes need warm growing conditions

Tomatoes are commonly grown from seed, they require a high germination temperature of between 16-30°C and have to be kept in the dark until they have germinated. So unlike a lot of vegetable that can be directly sown outdoors, you'll have greater success growing tomatoes indoors for the beginning of their life cycle.

Once germinated they can be moved to a kitchen windowsill, conservatory or greenhouse. Tomato plants are frost-sensitive so only move them outdoors once the last frost of the spring has passed.

2. Re-pot your plants

Sow your seeds into small module trays or paper cups. Once the plant has grown its second set of leaves, also known as its ‘true leaves’, you should re-pot the plant into a larger pot for the first time. This is called ‘potting on’ your plants. Each time you re-pot your plants they will have more space to spread their roots. I advise potting on twice for tomatoes, the final re-potting will be 3-4 weeks after the first. This final repotting should be in a large, deep pot or straight into the ground if you have a garden.

3. Tomatoes need support

As tomato plants grow larger, they need to be supported because they can grow very top-heavy, especially vining tomato plants. As you can see in this video, the plant is susceptible to damage from strong winds.

You can use a bamboo cane or straight stick to do this. Use a cane which is around 3-4ft long (you can go longer if you’re growing vining tomatoes). By using a cane that's taller than the plant currently is, you won’t need to replace it as the plant grows.

Insert the support stick close to the main stem of the plant, being careful to minimise damage to the roots of the plant. The key here is to decide where you will place the support and go for it.

Then you’ll need some garden twine or string to secure the stem to the stick. I’d recommend at least making two ties, adding more as the plant grows. Be careful not to tie these too tight as this could damage the plant, you also need to allow the plant some room to grow, so leave a little bit of slack in the twine.

4. How to Water Properly

watering can. How to water tomatoes correctly.

Tomatoes are great because they'll let you know if you have under-watered them. If this is the case their leaves will droop down. You should try not to let it to that stage by watering your plants every two to three days, however this will depend on how warm and humid the growing space is.

The hotter and drier it is, the quicker the soil will dry out, so it is best to pay attention to your plants. Learn more about how to tell when your plants need watering here. Try not to wet the leaves when watering, because this will increase the risk of a fungal disease called tomato blight.

5. Fertilise well

You can find liquid feed for tomatoes in many garden centres and pound stores. Using the instructions on the bottle, dilute the feed with water and then water onto the soil (try to avoid wetting the leaves).

Use the feed first when you re-pot your plants in to their final pot, or into a vegetable bed. After this, I advise fertilising tomato plants little and often.

Once your plants flower, fertilise them every two weeks (some swear by using fertiliser weekly) and do this until the first frost kills your tomato plants. If you notice too much leaf growth and less flower development, use less fertiliser; subsequently if you notice yellow leaves, increase the amount of fertiliser or the frequency of feeding.

6. Harden your plants off slowly

You shouldn’t move your plants outdoors in a hurry! Your plants will grow better if you slowly accustom them to outdoor conditions which have far more sunlight, wind and colder nights.

If you don’t have a mini greenhouse or cold frame, the easiest way to ‘harden off’ your plants is to take them outdoors in the day and move them indoors in the evening, doing this for a week will