Grow Tomato Plants from One Supermarket Tomato: The Slice Trick

Seeing the price of tomatoes in the shops each spring quickly raises the question of whether growing your own is worthwhile again. A British gardening expert has now demonstrated a technique that uses just one tomato to produce a whole tray of young plants – without costly seed packets and using items already found around the home.

Why this tomato trick is especially appealing right now

Tomatoes are a staple of British kitchens. Whether in salads, pasta sauces or sandwiches, they appear in the shopping basket almost every day. At the same time, food prices have risen noticeably. Anyone with a balcony, patio or simply a sunny windowsill can, with a little patience, grow some of their own summer tomatoes.

This straightforward supermarket tomato trick is ideal for exactly that. Rather than buying seeds, it makes use of the seeds already contained in every fruit. The key point is that the seeds stay inside the slice, so there is no need to pick them out individually. A single tomato can therefore create a whole ‘carpet’ of seedlings, ready to be pricked out and grown on later.

With very little effort, an everyday product from the chilled aisle becomes a small tomato plantation for summer.

The tomato slice trick: a step-by-step method

What you will need

• 1 ripe supermarket tomato, ideally a flavoursome variety
• 1 empty plastic fruit or vegetable punnet with holes in the base
• Seed compost or fine multi-purpose compost
• A watering can or spray bottle
• A bright spot on a windowsill or in a greenhouse

How to do it

Gardening expert Simon Akeroyd demonstrates just how simple this method is in a viral video. Rather than beginning with loose seeds, he starts directly with a shop-bought tomato.

1. Prepare the container: Fill the plastic punnet, such as one previously used for grapes or berries, with seed compost. Firm it gently and moisten it so that it is damp but not soaking wet.
2. Slice the tomato: Cut the tomato into four or five slices that are as even as possible. Every slice contains dozens of seeds.
3. Arrange the slices: Lay the tomato slices flat on the surface of the compost, leaving a little space between them.
4. Cover lightly: Add a thin layer of compost over the slices, using only enough to conceal the flesh.
5. Moisten carefully: Water gently with a spray bottle or a very fine rose, ensuring the slices are not washed away.

Then place the punnet somewhere warm and bright – a sunny windowsill is perfectly sufficient. After roughly one to two weeks, a dense covering of tiny green tomato seedlings will usually begin pushing through the compost.

The clever part is that both the packaging and the fruit are used in full – waste becomes a propagation station.

What to do once the tomato seedlings emerge

As soon as the seedlings develop their first ‘true’ leaves – rather than only the two narrow seed leaves – it is time for the most important stage: pricking them out. Leaving every plant in place risks producing weak, disease-prone tomatoes that will later bear only a small number of fruits.

Choose the strongest plants

• Pick out the most robust seedlings that are growing upright.
• Always hold a plant by a leaf, never by the stem, as stems break easily.
• Use a pencil or spoon to lift the compost slightly and carefully loosen the root ball.
• Plant each seedling in a small pot of fresh compost and water it in thoroughly.

The remaining seedlings can go onto the compost heap. That may seem harsh, but it saves space and effort while preventing too many plants from restricting each other’s growth.

The best timing and care in the UK

The expert begins this trick in spring in Great Britain. The crucial point is ensuring there is no longer any risk of frost when the plants are moved outdoors.

Region	Recommended indoor starting time
Southern England and milder lowland areas	Late February to mid-March
Central England, Wales and northern England	Early to late March
Cooler areas, Scotland and higher-altitude locations	March to early April

Young plants should remain indoors, in a conservatory or in a greenhouse until after the final night frosts. Before planting out, it is worth hardening them off for one week: put the pots outside in partial shade during the day, then bring them back inside in the evening. This helps plants adapt to wind, changing temperatures and sunlight.

How to encourage plenty of fruit later on

• Position: Choose a sheltered site with at least six hours of sun each day.
• Watering: Keep compost evenly moist while avoiding waterlogging. Water less often but more thoroughly.
• Feeding: Once flowering starts, feed regularly with tomato or vegetable fertiliser.
• Support: Use a cane or plant support so stems do not bend under the weight of the fruit.
• Pinching out side shoots: For cordon tomatoes, remove shoots growing from the leaf joints so the plant’s energy goes into the fruit.

Those who give their plants a good balance of light, warmth, water and nutrients will usually be rewarded with an impressive harvest.

What to consider when using a supermarket tomato

Technically, the trick nearly always works because a tomato contains many viable seeds. However, several factors can have a considerable effect on the result:

• Variety: Supermarket tomatoes often come from high-yielding cultivated varieties. The resulting plants can vary and may not be identical to the original fruit. This is usually not a problem for home gardeners and can be interesting in terms of flavour.
• Treatment of the fruit: In some countries, wax-based coatings or other treatments are used. Seeds in Europe will generally germinate regardless, although poor germination may be caused by this.
• Diseases: Fruit from professional growers is healthy in many cases. A small residual risk of seed-borne disease remains, but it is generally manageable for home growing.

Anyone wanting to play it safe can combine the trick with an organic tomato or a particularly flavoursome variety from the premium produce section. This improves the chances of producing tasty offspring.

Why the effort is worthwhile for balconies and gardens

The most obvious benefit is that home-grown tomatoes can save a noticeable amount of money. A pack of high-quality tomatoes can easily cost several pounds. If the experiment succeeds, a handful of plants can provide fruit for salads, sandwiches and sauces for weeks.

There is also the flavour. Tomatoes picked ripe from your own pot or bed have not spent days in the chilled aisle. Many home gardeners praise their more intense taste and better texture. Sustainability is another advantage: reusing existing plastic punnets creates less waste and conserves resources.

For families with children, the method also works well as a small experiment. Children can watch a slice gradually turn into a plant that later produces edible fruit. It can also make getting started with gardening feel less daunting – even without a garden, using only a windowsill.

Extra tips for even greater success with tomatoes in spring

Anyone already starting tomato plants can easily go one step further. Many people combine the slice method with conventional sowing in small pots, adding selected varieties such as colourful cherry tomatoes or beefsteak tomatoes. This creates a vibrant mix of experimental supermarket offspring and deliberately chosen varieties.

It is also sensible to consider the growing position. South-facing balconies can become very hot at the height of summer. In that case, light shade during the middle of the day can stop leaves and fruit from scorching. If you only have a north-facing window, a simple grow light can help. Tomatoes react strongly to insufficient light: they become tall and spindly, and later produce fewer flowers.

Air circulation is another frequently overlooked factor. Where plants are packed closely together in containers or a greenhouse, humid air can quickly build up. This encourages fungal diseases such as tomato blight. Leaving adequate gaps, regularly removing side shoots and airing the space from time to time significantly reduces this risk – including for plants raised from a supermarket tomato.

Anyone who gives the experiment a try will usually realise quickly that cutting into the tomato is the hardest part. Once the punnet has been filled with compost and slices, nature does much of the work itself – and by summer, in the best case, you may find yourself in your own tomato jungle above the dinner plate.