How to Prune Tomato Plants (UK Guide)

Pruning is one of the most important jobs when growing tomatoes in the UK. Done correctly, it improves airflow, reduces disease risk and dramatically increases fruit production.

Many gardeners are nervous about cutting their plants — but tomato plants actually perform better when pruned properly.

This guide explains how to prune tomato plants correctly, what to remove, and when to do it.

For full tomato growing advice, see TOMATOES: HOW TO GROW, BEST VARIETIES, PROBLEMS & EXPERT TIPS (UK GUIDE).

Do All Tomato Plants Need Pruning?

No — pruning depends on the type of tomato.

Cordon (Indeterminate) Tomatoes

These must be pruned regularly.
They grow tall and keep producing leaves and shoots all season.

Bush (Determinate) Tomatoes

These need very little pruning.
Over-pruning them actually reduces yield.

If unsure, see DETERMINATE VS INDETERMINATE TOMATOES.

Why Pruning Is Important

Proper pruning:

• Directs energy into fruit production
• Improves airflow
• Reduces fungal disease
• Prevents overcrowding
• Makes plants easier to manage

Unpruned greenhouse plants often become a tangled jungle with lots of leaves but little fruit.

The Most Important Job: Removing Side Shoots

Side shoots grow between the main stem and leaf branch.
They grow quickly and, if left, form new stems that divert energy away from fruit.

You should remove them weekly.

See WHAT ARE TOMATO SIDE SHOOTS? for identification help.

How to Remove Side Shoots

1. Check plants every few days
2. Pinch the small shoot between finger and thumb
3. Remove while small (under 5cm)

Small shoots snap off easily.
Large shoots should be cut cleanly.

Morning is the best time — plants are firm and wounds heal quickly.

Removing Lower Leaves

As the plant grows:

• Remove leaves touching soil or compost
• Remove yellowing foliage
• Improve airflow around the base

This helps prevent disease and reduces humidity around the stem.

Never remove too many leaves at once — the plant still needs foliage to photosynthesise.

Topping the Plant (Pinching Out)

Late summer, tomato plants keep growing but new flowers won’t have time to ripen.

At this stage:

• Pinch out the top growing tip
• Usually after 5–7 fruit trusses

This directs energy into ripening existing fruit.

Common Pruning Mistakes

• Removing healthy leaves too early
• Not removing side shoots
• Pruning bush varieties heavily
• Letting plants become overcrowded

The goal is balance — airflow without stripping the plant bare.

Pruning Outdoor Tomatoes

Outdoor plants require lighter pruning.

Focus on:

• Removing lower leaves
• Removing damaged foliage
• Improving airflow

Over-pruning outdoors can expose fruit to sunscald and slow growth.

Final Thoughts

Tomato pruning isn’t harmful — it’s essential for cordon varieties.
A few minutes weekly leads to healthier plants, fewer diseases and larger harvests.

Return to TOMATOES: HOW TO GROW, BEST VARIETIES, PROBLEMS & EXPERT TIPS (UK GUIDE) for complete tomato guidance.