How to Grow Tomatoes in the UK: Complete Guide

Growing tomatoes is one of the most rewarding things you can do in a garden, greenhouse, polytunnel or allotment. There’s something wonderful about picking a perfectly ripe tomato straight from the plant, especially when you’ve grown it yourself from a tiny seed.

Homegrown tomatoes can offer fantastic flavour, and there are hundreds of varieties to choose from, including sweet cherry tomatoes, traditional salad tomatoes, large beefsteak tomatoes and colourful heritage varieties.

However, growing tomatoes successfully in the UK requires a little planning.

Our unpredictable British weather can make tomato growing challenging, particularly during cold springs, wet summers and shorter growing seasons.

The good news is that tomatoes can thrive when given suitable warmth, sunshine, water and nutrients.

Whether you’re completely new to gardening or looking to improve your harvests, understanding the basics of tomato growing can make an enormous difference.

Here at Gardening with Ben, growing vegetables from seed is one of the great pleasures of allotment gardening. Tomatoes are particularly enjoyable because you can follow their progress throughout the season, from germination to flowering and eventually harvesting delicious fruits.

In this complete guide, we’ll explore how to grow tomatoes in the UK, including when to sow seeds, choosing varieties, planting, watering, feeding, pruning, dealing with common problems and harvesting your crop.

Can You Grow Tomatoes Successfully in the UK?

Yes. Tomatoes can grow extremely well in the UK.

However, they’re tender plants that require warmth and protection from frost.

Tomatoes belong to the nightshade family, Solanaceae, alongside potatoes, peppers and aubergines.

Their botanical name is Solanum lycopersicum.

In Britain, tomatoes are generally grown as annual crops, although they are perennial in suitable frost-free conditions.

Where Can You Grow Tomatoes?

Tomatoes can be grown in:

• Greenhouses
• Polytunnels
• Outdoor vegetable beds
• Raised beds
• Large containers
• Grow bags
• Hanging baskets
• Sunny patios

The best growing method depends on your available space, local climate and chosen variety.

When to Sow Tomato Seeds in the UK

Tomato seeds are generally sown indoors between February and April.

The ideal time depends on whether you intend to grow the plants under protection or outdoors.

February Sowing

February sowing can be suitable for gardeners with heated growing facilities and supplementary lighting.

However, starting seeds too early without enough light can produce weak, leggy seedlings.

March Sowing

March is an excellent month for starting greenhouse and polytunnel tomatoes.

Increasing daylight helps young plants grow strongly.

April Sowing

April is particularly suitable for tomatoes intended for outdoor growing.

Plants started in April can develop well before being planted outside after the final frost.

Should You Sow Tomatoes in January?

January sowing is generally unnecessary for most UK gardeners.

Without sufficient artificial lighting and warmth, plants may become weak before outdoor conditions are suitable.

Tomato Growing Calendar for the UK

Month	Gardening activity
January	Choose varieties and order seeds
February	Begin early sowings with suitable heat and light
March	Sow greenhouse tomatoes
April	Sow outdoor varieties and pot on seedlings
May	Plant into suitable protected growing positions
June	Plant outdoors after frost risk has passed
July	Water, feed, prune and begin harvesting
August	Continue harvesting and plant care
September	Harvest ripe tomatoes and monitor blight
October	Pick remaining fruits before cold weather
November	Clear spent plants and clean equipment
December	Plan next year’s varieties

These timings are approximate and should be adjusted according to local conditions.

Best Tomato Varieties to Grow in the UK

Choosing the right tomato variety is one of the most important decisions.

Some varieties are particularly suitable for greenhouses, while others perform well outdoors.

Gardener’s Delight

Gardener’s Delight is a popular cherry tomato variety.

It produces small, sweet fruits and is widely grown in British gardens.

It is generally a cordon variety that benefits from support and side-shoot removal.

Sungold

Sungold produces attractive orange cherry tomatoes.

It is particularly well known for its sweet flavour.

Sungold is commonly grown as a cordon tomato.

Moneymaker

Moneymaker is a traditional salad tomato variety.

It produces medium-sized fruits and is suitable for protected growing.

Alicante

Alicante is a popular salad tomato.

It is commonly grown in greenhouses and can also be grown outdoors in favourable conditions.

Shirley

Shirley is an F1 hybrid tomato often grown in greenhouses.

It produces medium-sized fruits and has resistance to certain tomato diseases.

Always check the supplier’s current resistance information.

Tumbling Tom

Tumbling Tom is a trailing tomato variety.

It is particularly suitable for hanging baskets and containers.

Roma

Roma-type tomatoes are commonly used for cooking and making sauces.

They produce fleshy fruits with relatively low moisture content.

Different Roma selections may have different growth habits, so check the seed packet.

Cordon Tomatoes vs Bush Tomatoes

Understanding the difference between cordon and bush tomatoes is essential.

Cordon Tomatoes

Cordon tomatoes are also called indeterminate tomatoes.

They continue producing a main growing stem and flower trusses throughout the growing season.

They usually require:

• Strong supports
• Regular tying in
• Side-shoot removal
• Suitable pruning
• Ongoing feeding and watering

Examples include Gardener’s Delight, Sungold and Moneymaker.

Bush Tomatoes

Bush tomatoes are also called determinate tomatoes.

They generally grow to a more limited size.

Many bush varieties require little or no side-shoot removal.

They’re particularly useful for containers and smaller spaces.

Comparison

Feature	Cordon tomatoes	Bush tomatoes
Growth habit	Tall and continuing	More compact
Support	Usually essential	Sometimes needed
Side-shoot removal	Usually recommended	Usually unnecessary
Container growing	Possible with large pots	Often particularly suitable
Harvest pattern	Often extended	Often more concentrated

How to Sow Tomato Seeds Step by Step

Growing tomatoes from seed is straightforward when suitable conditions are provided.

Step 1: Choose Suitable Containers

Use seed trays, modules or small pots with drainage holes.

Step 2: Fill with Compost

Use a suitable peat-free seed compost or fine multipurpose compost.

Gently firm the surface.

Step 3: Sow the Seeds

Sow seeds approximately 0.5cm deep, or follow the packet instructions.

Cover lightly with compost.

Step 4: Water Gently

Moisten the compost without washing seeds out of position.

Step 5: Provide Warmth

Tomato seeds germinate well at approximately 20–25°C.

A heated propagator can be useful.

Step 6: Wait for Germination

Many tomato seeds germinate within approximately 5–10 days under favourable conditions.

Cooler temperatures may delay emergence.

Step 7: Provide Light

Once seedlings emerge, move them into a bright position.

Remove propagator lids as appropriate to improve airflow.

Why Are My Tomato Seeds Not Germinating?

Poor germination can result from several problems.

Compost Is Too Cold

Low temperatures can slow or prevent germination.

Too Much Water

Waterlogged compost can encourage seed rot.

Not Enough Moisture

Seeds need consistent moisture to germinate.

Old Seeds

Seed viability declines over time, particularly when stored poorly.

Incorrect Sowing Depth

Seeds buried too deeply may struggle to emerge.

Follow the packet instructions.

How to Care for Tomato Seedlings

Young tomato seedlings need light, warmth and suitable moisture.

Provide Bright Light

Insufficient light can cause seedlings to become tall, thin and weak.

Avoid Overwatering

Keep the compost appropriately moist without leaving it saturated.

Maintain Suitable Temperatures

Young tomato plants grow best in warm conditions.

Avoid prolonged exposure to cold temperatures.

Improve Airflow

Gentle ventilation can help reduce excessive humidity and encourage stronger growth.

When to Pot On Tomato Seedlings

Tomato seedlings are usually ready for potting on when they have developed their first true leaves and are large enough to handle.

How to Pot On Tomatoes

1. Fill a slightly larger pot with suitable compost.
2. Carefully lift the seedling.
3. Handle it by a leaf or root ball rather than squeezing the stem.
4. Position it in the new pot.
5. Plant slightly deeper if the seedling is leggy.
6. Gently firm the compost.
7. Water carefully.

Tomatoes can produce additional roots along buried sections of stem.

This makes slightly deeper planting useful for certain leggy seedlings.

When to Plant Tomatoes in a Greenhouse

Tomatoes can be moved into a greenhouse or polytunnel once conditions are sufficiently warm.

In many UK gardens, this is during April or May, depending on whether the structure is heated.

An unheated greenhouse can become extremely cold at night.

Avoid planting too early simply because daytime temperatures feel warm.

Aim to keep young plants protected from frost and prolonged cold.

When to Plant Tomatoes Outside in the UK

Outdoor tomatoes should only be planted once the risk of frost has passed and the weather is consistently mild.

In many parts of the UK, late May or June is suitable.

In northern England, Scotland and exposed locations, June may be safer.

Hardening Off Tomato Plants

Before planting outdoors, gradually acclimatise the plants.

Place them outside in a sheltered position during suitable weather.

Increase exposure over approximately 7–14 days.

Bring plants back inside if cold conditions are forecast.

Best Position for Growing Tomatoes

Tomatoes prefer a sunny, warm and sheltered location.

Sunlight

Aim for at least six to eight hours of direct sunlight where possible.

Shelter

Strong winds can damage tomato plants and increase water stress.

Soil

Tomatoes prefer fertile, well-drained soil with sufficient organic matter.

Airflow

Good ventilation helps reduce prolonged humidity and certain disease problems.

How to Plant Tomatoes in the Ground

Step 1: Prepare the Soil

Remove weeds and incorporate suitable well-rotted compost if needed.

Step 2: Dig a Planting Hole

Make a hole large enough to accommodate the root ball.

Step 3: Remove the Plant

Gently remove the tomato from its container.

Step 4: Plant

Position the tomato at its previous growing depth or slightly deeper if appropriate.

Step 5: Water Thoroughly

Water around the root area to settle the soil.

Step 6: Provide Support

Install a suitable cane, string or frame for cordon varieties.

Step 7: Maintain Moisture

Keep the soil consistently moist as the plant establishes.

How Far Apart Should Tomato Plants Be?

Spacing depends on the variety and growing method.

Cordon tomatoes are often planted approximately 45–60cm apart.

Bush varieties may need different spacing depending on their mature size.

Follow the seed supplier’s recommendations.

Adequate spacing improves airflow and makes plant maintenance easier.

Growing Tomatoes in Pots

Tomatoes are excellent for container growing.

This is particularly useful for patios, balconies and small gardens.

Choosing a Container

For many cordon tomatoes, a container holding approximately 20–30 litres of compost or more is useful.

Large plants may benefit from additional root space.

Compact bush varieties may grow successfully in smaller containers.

Choosing Compost

Use a good-quality peat-free multipurpose compost suitable for growing vegetables.

Drainage

Ensure the pot has drainage holes.

Position

Place the container somewhere warm and sunny.

Watering

Containers can dry out quickly during summer.

Check moisture regularly.

Feeding

Container tomatoes usually require regular feeding once flowering and fruiting begin.

Growing Tomatoes in Grow Bags

Grow bags are a popular option for greenhouse and patio tomatoes.

Advantages

• Convenient to use
• Suitable for patios
• Useful for greenhouses
• Relatively easy to position

Disadvantages

• Compost can dry out quickly.
• Root space may be limited.
• Nutrients can become depleted.
• Watering requires careful attention.

Tips for Success

Use good-quality grow bags with sufficient compost volume.

Avoid overcrowding plants.

Provide suitable supports and maintain consistent moisture.

How Often Should You Water Tomato Plants?

Consistent watering is one of the most important parts of tomato growing.

Irregular watering can contribute to fruit cracking and blossom end rot.

Watering Young Plants

Keep compost lightly moist while plants establish.

Watering Mature Plants

Water thoroughly when the root zone begins drying.

Avoid repeated severe drought stress.

Watering Greenhouse Tomatoes

During hot weather, greenhouse tomatoes may require frequent watering.

Watering Container Tomatoes

Large plants in containers may need daily watering during warm summer conditions.

However, always check moisture before watering.

Best Time to Water

Early morning is often a convenient time.

Apply water around the roots rather than repeatedly soaking the foliage.

Best Fertiliser for Tomato Plants

Tomatoes require nutrients to support healthy growth, flowering and fruit development.

Feeding Young Plants

Young plants growing in fresh compost may not require additional feeding immediately.

Feeding Flowering Tomatoes

Once the first fruit truss begins setting fruit, a suitable tomato fertiliser can help support production.

Potassium

Potassium is important for fruit development and numerous plant processes.

Nitrogen

Nitrogen supports leafy growth.

However, excessive nitrogen can encourage foliage at the expense of fruit production.

How Often Should You Feed?

Follow the instructions on your chosen fertiliser.

Feeding frequency depends on the growing medium, plant size and nutrient availability.

How to Remove Tomato Side Shoots

Removing side shoots is an important task for many cordon tomato varieties.

Side shoots develop between the main stem and leaf stalks.

How to Identify Side Shoots

Look for small shoots emerging from the junction between the main stem and a leaf.

How to Remove Them

When small, gently pinch them out using your fingers.

Larger shoots may require clean secateurs.

Why Remove Side Shoots?

Removing side shoots helps maintain a single main stem and makes cordon plants easier to manage.

Should You Remove Side Shoots from Bush Tomatoes?

Usually not.

Bush tomatoes generally develop their fruiting structure differently.

Unnecessary pruning may reduce the harvest.

How to Support Tomato Plants

Cordon tomatoes can become tall and heavy.

Strong support is essential.

Bamboo Canes

Suitable for smaller plants and certain growing situations.

Tomato Strings

Commonly used in greenhouses.

Plants can be trained around secure vertical strings.

Tomato Cages

Useful for supporting bush and some semi-determinate varieties.

Plant Ties

Use soft ties and avoid fastening stems too tightly.

Check supports regularly as plants grow.

Should You Remove Lower Tomato Leaves?

Removing some lower leaves can improve airflow and access.

However, tomatoes need healthy foliage for photosynthesis.

Avoid removing large quantities unnecessarily.

When to Remove Leaves

Remove leaves that are:

• Yellowing naturally
• Diseased
• Touching wet soil
• Obstructing airflow significantly

Use clean tools where appropriate.

Avoid excessive pruning during hot weather because fruits may become exposed to intense sunlight.

Should You Stop Tomato Plants Growing Taller?

For cordon tomatoes, stopping the growing tip can help limit height and direct resources towards existing fruits.

This is particularly useful as the UK growing season approaches its end.

When to Stop Outdoor Tomatoes

Outdoor cordon tomatoes are often stopped after approximately four to five fruit trusses have formed, depending on the variety, growing conditions and available season.

When to Stop Greenhouse Tomatoes

Greenhouse plants may support more trusses because they have a longer protected growing season.

The appropriate number depends on the space and growing conditions.

How to Stop the Plant

Remove the growing tip above the uppermost truss you intend to keep, leaving sufficient foliage above it.

Do Tomatoes Need Pollinating?

Tomato flowers are generally self-fertile.

Each flower contains both male and female reproductive structures.

However, pollen still needs to move within the flower for successful fertilisation.

Outdoor Pollination

Wind and insects often provide enough movement.

Greenhouse Pollination

Gently tapping or shaking flowering stems can help release pollen.

Why Aren’t My Tomatoes Setting Fruit?

Possible causes include:

• Excessive heat
• Cold conditions
• Poor light
• Water stress
• High humidity
• Poor pollen transfer

Very high greenhouse temperatures can reduce fruit set.

Provide suitable ventilation.

Common Tomato Growing Problems

Tomato Blight

Late blight is caused by Phytophthora infestans.

It can cause dark leaf lesions, stem damage and fruit rotting.

Wet, humid conditions can encourage rapid spread.

To reduce risk:

• Choose varieties with useful resistance.
• Maintain suitable airflow.
• Avoid prolonged leaf wetness where practical.
• Monitor plants regularly.
• Remove affected material appropriately.
• Avoid leaving infected debris in the growing area.

Blossom End Rot

Blossom end rot causes dark, sunken patches on the blossom end of tomatoes.

It is associated with inadequate calcium reaching the developing fruit, often due to irregular water supply.

Maintain consistent moisture.

Adding calcium fertiliser without evidence of deficiency may not solve the problem.

Tomato Fruit Cracking

Cracking can occur when fruits experience sudden changes in water availability.

Maintain reasonably consistent soil moisture.

Yellow Tomato Leaves

Yellowing leaves may result from:

• Natural ageing
• Overwatering
• Nutrient deficiencies
• Root damage
• Disease
• Temperature stress

Inspect the plant carefully before taking action.

Tomato Leaf Curl

Leaf curling can be caused by environmental stress, irregular watering, temperature extremes or other problems.

Not every curled leaf indicates disease.

Whitefly

Whiteflies can become troublesome in greenhouses.

Monitor plants regularly and encourage appropriate biological controls.

Aphids

Aphids may gather on tender shoots.

Beneficial insects can help reduce populations.

Why Are My Tomatoes Not Turning Red?

Tomatoes require suitable temperatures and time to ripen.

If fruits remain green, possible causes include:

• Cool weather
• Excessive heat
• Immature fruits
• Late planting
• Insufficient light
• Plant stress

Tomato ripening generally proceeds well at moderate temperatures.

Very high temperatures can slow the development of red pigments.

As autumn approaches, lower temperatures can also delay ripening.

When to Harvest Tomatoes in the UK

Tomatoes are commonly harvested between July and October.

The exact period depends on the variety, sowing date and growing conditions.

Signs Tomatoes Are Ready

Look for:

• The expected mature colour
• Full fruit development
• Slight softening, depending on variety
• Easy separation from the plant when properly ripe

Harvesting Cherry Tomatoes

Pick when they reach their mature colour and flavour.

Harvesting Salad Tomatoes

Allow fruits to colour fully where possible.

Harvesting Beefsteak Tomatoes

Large varieties may take longer to mature.

Avoid leaving overripe fruits on the plant.

How to Harvest Tomatoes Correctly

Tomatoes can be harvested by gently lifting or twisting ripe fruits when they detach easily.

Alternatively, use clean scissors or secateurs.

Avoid pulling forcefully and damaging the stems.

Handle ripe tomatoes carefully because they bruise easily.

Can You Ripen Green Tomatoes Indoors?

Yes.

Mature green tomatoes can often continue ripening after being picked.

How to Ripen Tomatoes Indoors

Place healthy, mature green tomatoes somewhere at a suitable room temperature.

Keep them out of prolonged direct sunlight.

Check them regularly and remove any showing signs of decay.

A ripe banana or apple can sometimes help because these fruits release ethylene, a natural ripening hormone.

However, tomatoes must be sufficiently mature to ripen successfully.

Very immature green tomatoes may never develop good colour or flavour.

Can You Grow Tomatoes Every Year in the Same Soil?

Repeatedly growing tomatoes in the same soil can increase the risk of certain soil-borne problems.

Where practical, rotate tomatoes with unrelated crops.

Tomatoes belong to the same family as potatoes, peppers and aubergines.

Avoid following one crop with another susceptible crop if soil-borne disease is a concern.

In greenhouses, crop rotation may be difficult.

Maintaining healthy soil, using disease-free plants and managing growing conditions are important.

Can You Save Tomato Seeds?

Yes, seeds can be saved from suitable tomato varieties.

Choose Ripe Tomatoes

Select healthy, fully mature fruits.

Remove the Seeds

Scoop out the seeds and surrounding gel.

Clean and Dry

Use a suitable seed-cleaning method and dry the seeds thoroughly.

Store Carefully

Keep dried seeds somewhere cool and dry.

Will Saved Seeds Grow True?

Open-pollinated varieties often produce similar offspring when cross-pollination is avoided.

F1 hybrid varieties may not produce plants identical to their parents.

Frequently Asked Questions About Growing Tomatoes

What Month Should You Sow Tomatoes in the UK?

March and April are suitable for many gardeners, although earlier sowing is possible with adequate heat and light.

Can You Grow Tomatoes Outside in the UK?

Yes. Choose suitable varieties and plant after frost risk has passed.

Do Tomatoes Need a Greenhouse?

No. Many tomatoes grow successfully outdoors or in containers.

How Much Sun Do Tomatoes Need?

Approximately six to eight hours of direct sunshine is a useful target.

How Often Should You Water Tomatoes?

Water according to soil moisture, plant size and weather conditions. Consistency is important.

What Is the Best Fertiliser for Tomatoes?

A suitable tomato fertiliser can support flowering and fruit development.

Should You Remove Tomato Side Shoots?

Usually for cordon tomatoes, but not routinely for bush varieties.

Why Are My Tomato Flowers Falling Off?

Temperature extremes, water stress and poor pollination conditions can contribute to flower drop.

Why Are My Tomatoes Splitting?

Sudden changes in water availability can cause fruits to crack.

Why Are My Tomatoes Green?

They may need more time or suitable temperatures to ripen.

Can You Ripen Tomatoes After Picking?

Yes, if the fruits are sufficiently mature.

How Long Do Tomatoes Take to Grow from Seed?

Many varieties take approximately four to five months from sowing to their first ripe harvest, although conditions and varieties vary considerably.

Can You Grow Tomatoes in Hanging Baskets?

Yes. Choose suitable compact or trailing varieties.

Can You Grow Tomatoes in Pots?

Yes. Use appropriately sized containers with good drainage.

When Do You Harvest Tomatoes in the UK?

Usually from July to October, depending on growing conditions.

Final Thoughts: Growing Tomatoes Successfully in the UK

Growing tomatoes is one of the most enjoyable and productive gardening activities.

Whether you’re growing sweet cherry tomatoes, traditional salad varieties or large beefsteak tomatoes, the rewards of harvesting your own fresh fruit are fantastic.

The key to success is starting seeds at the right time, providing plenty of light and warmth, and choosing varieties suited to your growing conditions.

As the plants develop, maintain consistent watering, provide suitable nutrients and support cordon varieties properly.

Keep an eye out for common problems such as tomato blight, blossom end rot and fruit cracking.

With patience and regular care, you can enjoy delicious homegrown tomatoes throughout summer and into autumn.

Whether you grow them in a greenhouse, polytunnel, raised bed or a few containers on your patio, tomatoes are a crop well worth making room for.

Keep smiling, keep shining, keep gardening with Ben!