Grow a whole tray of tomato plants from one supermarket tomato

Tomato prices in the shops can make anyone wonder in spring whether growing their own is worthwhile again. A British gardening expert has demonstrated a method in which one tomato is enough to raise a whole tray of young plants – without expensive seed and using materials that are usually already at home.

Why this tomato trick is especially appealing right now

Tomatoes remain a staple in German kitchens. Whether used in salads, pasta sauces or on bread, they find their way into shopping baskets almost every day. At the same time, food prices have risen noticeably. Anyone with a balcony, patio or even just a sunny windowsill can, with a little patience, grow some of their own summer tomatoes.

That is precisely where this straightforward supermarket tomato trick comes in. Rather than buying seed, 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 painstakingly remove them. One tomato can therefore produce a whole “carpet” of seedlings, which can later be pricked out and grown on.

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

The sliced tomato trick: how it works step by step

What you will need

• 1 ripe supermarket tomato, ideally a flavoursome variety
• 1 empty plastic fruit or vegetable tray with holes in the base
• Seed compost or fine potting compost
• A watering can or spray bottle
• A bright spot by a window or in a greenhouse

The method

In a viral video, gardening expert Simon Akeroyd shows just how simple the technique is. He does not begin with loose seeds, but with a tomato bought from the shop.

1. Prepare the container: Fill the plastic tray – for example, one previously used for grapes or berries – with seed compost. Firm the compost lightly and moisten it so that it is damp but not soaking wet.
2. Slice the tomato: Cut the tomato into four or five slices of roughly equal thickness. Each slice contains dozens of seeds.
3. Place the slices: Lay the tomato slices flat on the compost surface, leaving a little space between them.
4. Cover lightly: Add a thin layer of compost over the slices, using just enough to cover the flesh.
5. Moisten gently: Water carefully with a spray bottle or a very fine rose, so the slices are not washed out of place.

Then place the tray somewhere warm and bright; a sunny windowsill is perfectly sufficient. Within around one to two weeks, a dense carpet of tiny green tomato seedlings will usually emerge from 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 have germinated

As soon as the seedlings develop their first “true” leaves – rather than only the two very narrow seed leaves – the most important stage begins: pricking them out. Leaving every little plant where it is can result in weak, disease-prone tomatoes that later produce only a small number of fruits.

Choose the strongest plants

• Pick out the most vigorous seedlings that are growing upright.
• Always hold a seedling by a leaf, never by the stem, as the stem can 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 filled with fresh compost, then water it thoroughly.

The remaining seedlings can go on the compost heap. It may seem harsh, but it saves space and effort while preventing too many plants from restricting one another’s growth.

The right timing and care in German-speaking regions

The expert begins this trick in spring in Great Britain. It can be adapted easily for Germany, Austria and Switzerland. The crucial factor is ensuring that there is no longer any risk of frost when the plants are moved outdoors.

Region	Recommended time to start indoors
Southern Germany, lower-lying areas of Austria and Switzerland	Late February to mid-March
Upland areas, northern Germany	Early to late March
Cooler locations, the Alps and high-altitude valleys	March to early April

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

How tomato plants later produce plenty of fruit

• Position: At least six hours of sunshine each day, in a sheltered spot.
• Watering: Keep the compost evenly moist and avoid waterlogging. Water less often but more thoroughly.
• Feeding: Once flowers begin to form, feed regularly with tomato or vegetable fertiliser.
• Support: Use a cane or climbing support so that stems do not snap under the weight of the fruit.
• Pinching out: On cordon tomatoes, remove shoots that develop in the leaf axils so the plant can direct its energy into fruit production.

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

What to bear in mind when using a supermarket tomato

Technically, this trick works almost every time because a tomato contains many viable seeds. Even so, several factors can have a considerable effect on the result:

• The variety: Supermarket tomatoes often come from high-yielding cultivated varieties. The resulting plants can vary and will not always match the original fruit exactly. For home growers, this is usually not a problem, and the flavour can be interesting.
• Treatment of the fruit: In some countries, wax-based coatings or other treatments are used. In Europe, the seeds will generally still germinate, although weak germination may be caused by this.
• Diseases: Fruit from professional growing operations is healthy in many cases. A small residual risk of seed-borne disease remains, but it is generally manageable in a home-growing setting.

Anyone wanting to be extra cautious can combine the trick with an organic tomato or an especially flavoursome variety from the delicatessen aisle. 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 quickly 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 a pot or garden bed have not spent days in the chilled aisle. Many home gardeners rave about their more intense taste and better texture. Sustainability is another advantage: reusing existing plastic trays creates less waste and conserves resources.

For families with children, the method works well as a small experiment. Children can watch a plant gradually develop from a slice before it eventually produces edible fruit. It also makes starting to garden feel less daunting, even without a garden and with only a windowsill available.

Extra tips for even more success with tomatoes in spring

Anyone already raising tomatoes can easily take the process a step further. Many people combine the sliced tomato method with traditional sowing in pots to add particular varieties, such as colourful cherry tomatoes or beef tomatoes. This creates a vibrant mix of experimental supermarket offspring and deliberately selected varieties.

It is also sensible to consider the growing position. South-facing balconies can become extremely hot at the height of summer. In that case, light shade during the midday heat helps prevent leaves and fruits from scorching. Anyone with only a north-facing window can provide extra light with a simple plant lamp. Tomatoes react strongly to insufficient light: they become tall and spindly, then produce fewer flowers later on.

Air circulation is another point that is often underestimated. Humid air can quickly build up, particularly where plants are packed closely together in containers or a greenhouse. This encourages fungal diseases such as blight. Leaving adequate gaps, pinching out regularly and ventilating from time to time significantly reduces the risk – including for plants grown from a supermarket tomato.

Those willing to try the experiment usually realise quickly that the hardest part is making the first cut into the tomato. Once the tray has been filled with compost and slices, nature does much of the work itself – and, in the best case, you could be leaning over your own tomato jungle in summer, ready to serve dinner.