Beginner’s Guide to Planting and Growing Tomatoes

Have you ever tasted a tomato fresh from the garden? The flavour is rich and sweet, isn’t it? So unlike that tasteless produce you find at your local shop.

Your salads, sauces, and other dishes are so much better with homegrown tomatoes, and your wallet is also happy. Are you finally convinced to try and grow some of your own?

Then this guide will show you how to plant tomatoes properly. From picking the right sort to how to care for it, you will learn how to grow your fruits to their full sweet potential.

First, let’s answer a fundamental question…

What tomato variety will thrive in your UK garden?

In the UK climate, you can grow two types of tomatoes: bush (determinate) and cordon (indeterminate).

Bush tomatoes stay compact and stop once they reach a set height. They work best for pots, hanging baskets, or small gardens.

Cordon tomatoes, on the other hand, keep growing tall. For that reason, they need staking or tying to supports. They do well in greenhouses or warm outdoor spots.

With that said, the popular tomato choices are:

If you ask what is the easiest tomato plant to grow out of these three, the answer is cherry tomatoes. They handle the UK weather very well and still give a steady crop.

Now let’s delve into the next logical question…do tomato plants do better in pots or in the ground? Both methods can work, actually. Pots let you control soil and move plants to sunny spots. Soil, on the other hand, gives more root space and can support stronger growth.

When is it best to start planting tomatoes?

Tomatoes need warmth and light. You already know that our UK climate often lacks that when it’s early in the year. To succeed, you must match your planting method to the season.

What are the correct steps to plant tomatoes?

To enjoy the fruits of your labour, you need to know exactly how to plant tomatoes and look after them.

Step 1: Start seeds indoors

Start your tomato crop with fresh seeds. Fill trays or small pots with fine compost and press each seed about 0.5 cm deep. Leave space so the plants do not compete too soon. Keep the compost damp but not wet. Too much water can rot the seed.

Place the pot on a sunny south-facing windowsill if you have one. If not, go with the already mentioned grow light. Your fruits need at least 12–16 hours of light per day. That will keep the seedlings compact and stop them from stretching tall and thin.

In this line of thought it’s worth to demystify a common misconception. Many people ask whether you should put rocks in the bottom of tomato pots. They think rocks improve drainage. The answer is no. In fact, rocks reduce the soil’s available space for roots and water collects above the rocks instead of draining. That can lead to root rot.

Step 2: Potting on seedlings

Once the seedlings form two sets of true leaves, move them into larger pots. Hold each plant by the leaves, not the stem. The stem bruises easily and damage there can slow growth.

Fill the new pots with fresh compost to feed the roots and give space to spread. Firm the compost around the roots and water well. This step strengthens the plants and prepares them for life outside or in a greenhouse.

Step 3: Preparing the soil or compost

You need rich, well-drained soil for your tomatoes, so how do you prepare it? In garden beds, dig in plenty of compost or well-rotted manure. This will feed the roots and improve the soil so it holds water without turning heavy.

If you grow in containers, on the other hand, use deep pots, raised beds, or grow bags. These give the roots space to spread. Remember, always choose a mix that drains freely.

Put a slow-release feed in the holes before you plant. This gives steady nutrients through the season and helps the plants build strong growth and heavy crops.

Some gardeners wonder if adding Epsom salt when planting tomatoes is beneficial. You can add a little bit to supply magnesium. Use about 1 tablespoon per plant in the hole or mix it into the soil. Don’t overdo it, as too much can upset the soil. Honestly, regular compost and slow-release fertiliser usually give enough nutrients, so even if you don’t add this salt, you will be good.

Step 4: Planting depth

Plant tomatoes deeper than most crops. Bury the stem up to the first set of true leaves, usually 8-15 cm deep. Remove any leaves that would sit under the soil. 

The buried stem forms extra roots, which anchor the plant and draw more water and food. This makes the plant sturdier and less likely to topple in wind.

In pots or grow bags, set the plant 8 – 10 cm deeper than it was in its original pot. Afterwards firm the compost and top up the soil around the base.

In garden beds, if the plant is tall or leggy, make a shallow trench, lay the stem sideways, bury 10 – 15 cm of it, and bend the tip upward so it continues to grow straight. Roots will form along the buried stem and provide strong support.

Step 5: Spacing guidelines

Space tomatoes well so air can move around them. In garden beds, leave 45–60 cm between plants. Use the same spacing if you plant them in a greenhouse.

In pots, grow one plant per container at least 30 cm wide with holes for drainage. In grow bags, place two plants per bag, or three if the bag is large. Good spacing keeps plants healthy and makes sure each one has enough food, light, and airflow for a heavy crop.

You already know that tomatoes like direct sunlight. Keep that in mind when you choose a spot in your garden.

Tomato care and ripening tips

Your tomatoes will grow best when they get steady care through the season.

Watering

Water deeply and regularly only at the base of each plant. Never water from top to bottom. Wet foliage invites disease, that’s why leaves should always be dry. Outdoor plants often need extra water during dry spells. If you ask how to grow tomatoes outside, steady watering is the most important rule to follow.

Feeding

Start to feed once fruit begins to form. Use a high-potash tomato fertiliser to boost size and flavour. That’s the best fertiliser, frankly. For container plants, choose compost that holds water and nutrients but still drains well.

Supporting plants

Train cordon (indeterminate) tomatoes up a stake and tie them as they grow taller. Bush varieties stay smaller and usually need no support. If you plant outdoors early, cover young plants with cloches or fleece to protect them from cold nights.

Pruning

Pinch out side shoots that grow between the main stem and leaves on cordon plants. This keeps growth focused on fruit instead of excess foliage. Bush tomatoes do not need pruning.

There is also a way to get more tomatoes per plant and here is how. Pick ripe fruit often. This will encourage the plant to set more. Feed once a week to keep growth steady and remove yellow or damaged leaves. This will allow light and air to reach the fruit. 

You likely will get pests like whitefly and aphids sooner or later. Fortunately, you can repel them with some companion panting. Grow tomatoes with basil, marigolds, or garlic. These plants will help significantly.

However you should also know what not to plant tomatoes with. Avoid potatoes, cabbages, and fennel as these compete too much for food or share the same diseases.

How long do tomatoes take to ripen on the plant?

Most tomatoes ripen 60 to 85 days after you plant them outdoors. The time depends on variety, sunlight, and temperature. Warm, bright conditions speed the process, while cool, cloudy days slow it down.

If you wonder how to make tomatoes ripen faster on the plant, try these tips:

Common tomato problems and how to deal with them

Even the best cared-for plants can run into trouble. Here are the most common issues and how to handle them.

Tomato blight prevention. Blight spreads fast in damp, cool weather. For that reason space plants so that air moves freely between them. You already know you should avoid wetting the leaves when you water. If you find any infected leaves, remove them at once to slow the spread.

Greenhouse humidity control. High humidity in greenhouses makes plants prone to mould and disease. Open vents or doors so it doesn’t come to fruition. Also water the base of plants in the morning so excess moisture can dry through the day.

Pest control. The already mentioned aphids and whitefly weaken plants when they suck their sap. You can spray them off with water and soap, or use a mild insect soap that kills the bugs without harming the plant. Do that in addition to the companion plants and you should be good to go.

Blossom end rot. This shows as dark patches on the base of fruits. It often comes from uneven watering, which affects calcium uptake. Keep soil moist at all times, and avoid long dry spells followed by heavy soaking.

Tomatoes stopped growing. You may ask, why has my tomato plant stopped growing? Common reasons are poor soil, lack of feed, or cold weather. Check that the plant has enough nutrients, warmth, and light. Pinching out too many shoots at once can also slow growth.

When is the time to harvest tomatoes and how?

In a way tomatoes tell you when they are ready. The fruit turns a deep, even colour – red, yellow, or orange, depending on the variety. When you squeeze the fruit you will sense slight softness. This is another sign it is ripe.

Now you know when, but how do you harvest tomatoes from plant? Use scissors or pinch the stem just above the fruit. If you pull, you can damage the plant. For greenhouse crops, you may pick earlier, as warmth helps them finish ripening indoors. Outdoor plants often ripen slower, so wait for full colour before you pick.

As autumn sets in, many plants still hold green fruit. You can pick green fruit and ripen it indoors on a sunny windowsill or in a paper bag with a ripe banana. If some stay firm, use them for chutney or cooking. And what month do tomatoes stop? In the UK, most plants slow right down by September or October, as nights grow cold. 

Takeaways