Your Ultimate Guide to Pruning Tomato Plants

How to Prune Tomatoes for Your Best Harvest Yet  

Pruning tomato plants might seem like one of those mysterious gardening skills that only the pros know, but I promise – it's simpler than you think. More importantly, it can mean the difference between a mediocre harvest and baskets full of juicy, sun-ripened tomatoes.  

Do I Really Need to Prune My Tomatoes?

The short answer? Yes, There are a few reasons why tomato plants need pruning.

Firstly it encourages bigger, better quality fruits. But importantly, it also improves air circulation (vital for preventing disease) and allows sunlight to reach all parts of the plant both of which make pest control easier  

However, not all tomatoes are created equal. 

Cordon (indeterminate) varieties

The ones that keep growing taller – absolutely need pruning. Left to their own devices, they'll put all their energy into growing leaves rather than fruit.  

Bush (determinate) varieties –

The more compact types – generally don't need much pruning at all. A light tidy-up is all they require.  

5 Tell-Tale Signs Your Tomatoes Need Pruning  

Wondering when to grab those pruners? Look out for these signs:  

1. Suckers appearing – These are the small shoots that grow between the main stem and branches. Pinch them out when they're small (about 2-3cm long).  

2. Yellowing lower leaves – These older leaves aren't doing much for the plant and can be removed.  

3. Overcrowded growth – If leaves are overlapping and creating dense shade, it's time for a trim.  

4. Flowers developing – This is when you want to direct energy to fruit production.  

5. Signs of disease – Remove affected leaves immediately (more on this later).  

The Essential Pruning Toolkit  

Before you start snipping away, make sure you've got the right tools for the job.  

Basic toolkit:

• Sharp, clean secateurs or scissors

• Gardening gloves (tomato sap can irritate skin)

• Disinfectant for cleaning tools between plants

Tool care tips:

• Clean blades with disinfectant after each plant - that's where your spray will come in handy

• Keep tools sharp for clean cuts - jagged edges take longer to heal allowing disease in

• Wipe away sap immediately to prevent sticking

The Best Time to Prune Tomatoes  

Timing is everything when it comes to pruning:  

Early morning is ideal – plants recover better when they have the whole day ahead.  

Avoid pruning Tomatoes:

- When plants are wet (spreads disease)  
- During the hottest part of the day (can stress plants)  
- Late in the season (plants need leaves to ripen remaining fruit)  

Weekly maintenance is better than occasional heavy pruning. Just 5 minutes every few days keeps plants in perfect shape.  

Step-by-Step Tomato Pruning Guide  

Step 1: Remove suckers

- Identify the small shoots between main stem and branches  
- Pinch out with fingers when small or use pruners if woody  

Step 2: Trim lower leaves

- Remove leaves touching the ground  
- Clear the first 15-20cm of stem as plant grows  

Step 3: Thin out dense areas

- Remove some inner leaves to improve air flow  
- Focus on leaves that shade developing fruit  

Step 4: Top plants late season

- About 4 weeks before first frost  
- Cut off top of main stem to stop new growth  

 3 Diseases to Watch For When Pruning  

Pruning is the perfect time to spot and deal with these common tomato problems:  

1. Blight

- Signs: Brown patches on leaves, white mould underneath  
- Action: Remove affected leaves immediately, avoid overhead watering  
- Prevention: protect with a micromesh cover 

2. Leaf Spot

- Signs: Small dark spots with yellow halos  
- Action: Remove infected leaves, improve air circulation  
- Prevention: Water at base of plant only  

3. Powdery Mildew

- Signs: White powdery coating on leaves  
- Action: Remove affected leaves, spray with milk solution (1:9 milk to water)  
- Prevention: Ensure good spacing between plants  

Common Tomato Pruning Mistakes to Avoid  

Even experienced gardeners sometimes slip up with these:  

Over-pruning – Never remove more than 1/3 of foliage at once  

Using blunt tools – Crushed stems invite disease (that's why our Precision Pruners are worth every penny)  

Pruning in wet weather – Water droplets spread fungal spores  

Ignoring plant signals – If a plant looks stressed, hold off on pruning  

Aftercare: What to Do After Pruning  

Your plants need a little TLC after their trim:  

Water carefully – Avoid wetting the fresh cuts  

Feed lightly – especially after pruning to support recovery  

 Special Cases: Pruning Greenhouse vs Outdoor Tomatoes  

Greenhouse tomatoes:  
- Need more aggressive pruning due to higher humidity  
- Remove more leaves to improve air flow   

Outdoor tomatoes:  
- Leave slightly more foliage for weather protection  
- Watch for wind damage on newly pruned plants  

When to Stop Pruning  

As summer winds down:  
- Stop removing suckers about 4 weeks before first frost  
- Leave all healthy leaves to help ripen remaining fruit  
- Switch focus to harvesting rather than plant maintenance  

Why Pruning Tomatoes is essential

The thing to remember about growing tomatoes is that the plant has two jobs to do.  Grow leaves and grow fruit.  So unlike other plants where tons of bushy leaves equate to a better plant - with tomato plants you do not want them wasting all of their energy on leaves when they have juicy tomatoes to produce.  

Tomato Growing Tools

Before you go we have a number of tomato growing products that will help you along the way and up your tomato growing efforts so you don't have to eat supermarket tomatoes at all this summer. 

The Tomato Crop Booster frame uses the patented TerderBrace support system to support your tomatoes properly allowing them to put all of their energy into growing fruit.  Proven in trials to give a bigger yield of tomatoes.

The Twist Up Tomato Cloche provides a cosy, moist growing environment and help to protect against blight, slugs and harsh weather.  Most useful early in the season but could certainly be useful in the heavy hail showers that are becoming more common in summer.  

To grow them in we can improve on your growbag with dedicated tomato planters - either the pack of 2 Tomato Planters which do the job brilliantly with reinforced handles and good drainage holes or the Vigoroot Tomato planter made from air-pruning fabric for those who want a bigger yield but are short of space. Or if you need one with its own support then the Climbing Tomato Patio planter could be just the thing 

And of course there is Soft Tie - the perfect plant tie to support your heavy tomato plants without damaging the stems and allowing diseases to take hold. So when you are pruning tomato plants make sure to look out for any that need extra support.