Pruning Tomato Plants: 6 Mistakes Most First-Time Growers Make

Proper pruning is one of the most important things you can do to keep your tomato plants healthy and productive. While it may seem counterintuitive to cut off perfectly good branches and leaves, strategic pruning strengthens the plant and maximizes fruit yields.

Pruning isn’t difficult, but there are a few common mistakes tomato growers make. Avoid these pruning pitfalls and you’ll be rewarded with bumper crops of beautiful, delicious tomatoes.

In This Article

Pruning Tomato Plants: 6 Mistakes Most First-Time Growers Make

Why You Should Prune Tomatoes?

Pruning tomato plants accomplishes several things:

  • Removes non-productive suckers and excess foliage so the plant’s energy goes towards developing fruit instead of unnecessary leaves and stems.
  • Opens up the plant canopy to allow better airflow and light penetration. This reduces moisture and the risk of disease.
  • Allows you to train and support plants, keeping fruits off the ground and preventing rot.
  • Gives you better spray coverage when applying fertilizers, pest control, or disease prevention products.
  • Makes harvesting easier with better access to ripe tomatoes hidden by foliage.
  • Improves overall plant shape for easier management in small spaces.

Proper pruning also enhances fruit quality:

  • More sunlight exposure means higher sugar content and better tomato flavor.
  • Cutting off competing shoots means nourishment is focused on existing fruit, leading to larger tomatoes.
  • An open canopy reduces foliar disease that can disfigure or damage fruits.

The bottom line, is that pruning tomato plants means healthier, more productive plants and much higher yields of beautiful, delicious tomatoes to enjoy all season long.

Determinate vs. Indeterminate Tomatoes

The most important thing to know before pruning tomato plants is to recognize whether you have determinate or indeterminate varieties. This determines the pruning method:

Determinate Tomatoes

  • Also known as “bush” types.
  • Reach a compact height, usually 3-4 feet.
  • Stop growing once fruit sets on terminal buds.
  • Do not need pruning except to remove lower leaves or damaged foliage.
  • Examples: Celebrity, Roma, Early Girl, Ace 55.

Indeterminate Tomatoes

  • Also known as “vining” types.
  • Keep growing and producing fruit all season until killed by frost.
  • Grow tall, reaching 6 feet or more if not staked.
  • Require pruning and staking/caging for best results.
  • Examples: Brandywine, Beefsteak, Cherokee Purple, Black Krim.

So determinate varieties should never be pruned the same as indeterminates. Removing suckers or pinching on determinate tomatoes will sacrifice some fruit production.

Pruning Means Improved Airflow

One of the biggest benefits of pruning tomato plants is opening up the plant canopy to allow better airflow. This serves several purposes:

  • Prevents moisture buildup on leaves and stems that can lead to foliar fungal and bacterial diseases. These include early blight, late blight, and bacterial spot which all thrive in humid conditions. Good airflow keeps the foliage drier.
  • Improves pollination and fruit set by allowing better access for bees and other pollinators into the plant canopy.
  • Allows any sprays such as fertilizer, pesticides, or disease prevention products to penetrate deeper into the plant foliage for better coverage.
  • Prevents mildew and mold growth.

Aim to remove enough foliage to open up the canopy without going overboard and stressing the plants. A good rule of thumb is to be able to see some light through the plant without leaves touching each other.

Pruning Means Bigger Fruit

Pruning tomato suckers and excessive foliage forces the plant to focus its energy on the existing fruit rather than grow more vegetation. The result is usually larger fruit size and higher total yield per plant.

Think of it like this – a plant can only support so many fruits. Would you rather have 20 smaller tomatoes or 10 bigger tomatoes on each plant? Plus larger fruit often store better and have a longer shelf life once picked.

Follow these tips for the biggest tomatoes from pruning:

  • Prune properly and consistently through the growing season to control excess growth.
  • Leave only 1-2 suckers per plant, ideally ones that don’t compete with existing fruiting branches.
  • Remove the first few flower clusters to let plants establish size and strength before fruiting.

When to Prune Tomato Plants?

Proper tomato pruning starts early in the season and continues regularly as plants grow:

  • Start pruning – When transplant seedlings are 12-18 inches tall.
  • First flowers – Prune determinate varieties lightly, avoiding any flowering stems.
  • Before frost – Prune indeterminate varieties until 2-3 weeks before the expected first fall frost.
  • Frequency – Check for new suckers and excessive growth weekly at minimum.

Some other tips regarding tomato pruning timing:

  • Ideally prune on a sunny, dry day to minimize stress and disease entry. Avoid pruning wet plants.
  • Prune in the mornings when leaves are less prone to sun-scald.
  • Remove lower leaves gradually over time rather than all at once.
  • For late plantings, you can prune more aggressively to limit size before frost.

Consistent, timely pruning is key. Don’t allow excessive foliage and shoots to grow out of control.

How To Prune Tomatoes

Tomato pruning does not require expensive or specialized tools. Bypass hand pruners are ideal, but even a sharp pair of scissors or garden snips will work.

The key points are using a clean, sterilized, and very sharp tool to ensure the best pruning cuts. Dull tools will crush and tear plant tissues.

Follow this basic process when pruning tomato plants:

1. Remove Diseased and Dead Foliage

Always start any pruning session by first removing yellow, withered, or damaged leaves and stems which can harbor pests and disease. Check under leaves for insects. Remove any branches or foliage with spots, lesions, or other evidence of disease.

To limit spread, dip your pruning shears into a 10% bleach solution or rubbing alcohol between cuts. Or use dedicated shears for diseased plants only.

2. Snip Off Suckers

Suckers are shoots that form in the joint between the main stem and branches. Left to grow, they divert energy away from fruit production.

Identify suckers by their distinctive singled-stalked appearance. Firmly pinch the base between your fingers and snip off right against the main stem. Be diligent as new suckers continually form.

3. Prune Off Lower Leaves and Branches

Leaves or branches touching the ground can transmit soil diseases. Start by removing the lowest 1-2 sets of leaves soon after transplanting.

As the plants grow, gradually remove additional lower leaves up to the first fruit cluster to improve air circulation. Avoid over-pruning lower foliage too early before plants are established.

4. Train and Top Indeterminate Varieties

Indeterminate tomatoes will grow lanky and spindly without pruning and support. When plants reach 2-3 feet tall, pinch or snip off 3-4 inches from the top to encourage bushier growth. Add tomato cages or stakes at this time too.

As plants grow, check 1-2 times per week for any branches getting too long and out of control. Trim them back by 6 inches or so to encourage more side shoots and fruit clusters.

5. Check for and Correct Excessive Growth

Keep an eye out for any rapidly growing shoots that are encroaching on other stems. Prune them back by 6 inches or so to maintain even growth and light penetration.

Common Pruning Mistakes

Even experienced gardeners sometimes make pruning errors. Be aware of these common tomato pruning mistakes:

  • Pruning determinate varieties too aggressively – avoid cutting flowers and fruiting stems.
  • Leaving stubs when removing suckers which invite disease. Snip suckers flush with the main stem.
  • Using unsterilized or dirty tools spreads infection between plants.
  • Over-pruning lower leaves early on before plants are established.
  • Not pruning indeterminate varieties enough leads to leggy, spindly plants.
  • Pruning too late in the season after diseases have taken hold.
  • Pruning in hot midday sun which stresses plants.

The key is finding the right pruning balance – not too much and not too little. With a little trial and error, you’ll get a feel for properly pruning your tomato plants.

The Correct Way to Prune a Tomato Plant

There are a few different pruning techniques tomato growers use with indeterminate varieties:

Simple Pruning

This involves:

  • Removing all suckers – leave at most 1-2 per plant
  • Snipping off lower leaves and branches touching the ground
  • Pinching off 3-4 inches from the top when plants are 2-3 feet tall
  • Removing any diseased or dead foliage

Simple pruning is suitable for most home growers and keeps plants manageable with good yields.

Missouri Pruning

Developed for commercial growers, this is a more aggressive pruning method to optimize fruit production:

  • All foliage and suckers are removed up to the first fruit cluster.
  • Only leaves immediately above the first fruit set are left intact.
  • Can be done early in the season up to the first flower clusters.

While it leaves more scarring on the stem, Missouri pruning shifts all growth towards fruit development rather than leaves and vines. It does take more effort and plant stress though.

Topping and Training

For very tall indeterminate varieties staked to 10 feet or more:

  • Allow 2-3 main leaders to grow with regular topping to encourage lateral shoots.
  • Train leaders loosely to stakes as they grow, weaving stems through garden twine.
  • Remove all suckers and leaves below the top flower/fruit cluster.

This technique is used by some commercial tomato growers producing very large plants. It requires tall, sturdy stakes and more tying as plants grow but maximizes production.

Tomato Pruning Mistakes to Avoid

It takes some practice to master proper tomato pruning techniques. Be aware of these common pruning mistakes:

1. Pruning determinate tomato plants incorrectly.

Determinate tomatoes should never be pruned aggressively like indeterminate varieties. Removing suckers and foliage will only remove fruiting branches, reducing yields.

2. Pruning when the plants are wet.

Wet foliage is very fragile and your pruning shears will simply shred leaves rather than make clean cuts. Wet tools can also spread disease between plants. Always prune once plants have dried after rain or watering.

3. Using dirty or dull pruning tools.

A clean, sharp pair of bypass hand pruners will make the best pruning cuts. Use rubbing alcohol to sterilize tools between plants to avoid transmitting blight or wilt diseases through open wounds.

4. Waiting too long to prune overgrown tomato plants.

Don’t allow suckers and branches to grow too large before pruning. Making smaller, frequent prunings removes less plant resources than one drastic chop.

5. Over-pruning tomato plants.

Removing too much foliage starves plants of the ability to photosynthesize and causes stress. Stick to minimal suckers, lower leaves, and strategic pinching of branch tips.

6. Not topping indeterminate varieties.

Failing to pinch off tall top growth results in leggy, weak plants. Top regularly once flowering starts to encourage bushy growth.

Avoiding these common errors will lead to successfully pruned tomato plants and bumper harvests!

How To Prune Tomato Plants?

A Simple Pruning Makes Productive Plants

Tomato plants respond so well to correct pruning. Just a few simple snips make all the difference in plant health, fruit production, and ease of harvesting. Here’s a quick guide to pruning tomato plants successfully:

Why Prune Tomatoes?

  • Redirects energy towards fruit rather than excess foliage
  • Allows better light and airflow to reduce disease
  • Keeps fruits clean and off the ground
  • Gives better access to care and harvesting
  • Maximizes yields in a limited space

Pruning Tips

  • Use clean, sharp bypass hand pruners for the best cuts
  • Remove suckers weekly by snipping at the base
  • Prune off lower leaves and branches touching soil
  • For indeterminates, pinch off 3-4 inches of top growth
  • Stop pruning determinates when flowers appear
  • Avoid over-pruning -moderation is key

Supporting Pruned Plants

Add stakes or cages to support fruit-laden plants after pruning. Trellising prevents broken branches. Match support size to mature plant height.

Benefits of Pruning Tomato Plants

Taking the time to prune tomato plants properly pays off all season long with these benefits:

  • Higher total yields – With less foliage competing for resources, more energy goes towards fruit production.
  • Lower disease pressure – An open canopy has better airflow and light exposure to reduce foliar fungus and bacteria.
  • Larger fruit size – Again, with less plant tissue to support, nourishment is focused on developing bigger tomatoes.
  • Easier harvesting – Removing leaves and shoots gives you better access to find and pick ripe tomatoes.
  • Better spray coverage – An open plant allows sprays to better penetrate to where they’re needed.
  • Extended harvest period – Regular pruning encourages continuous new flower and fruit production.
  • Efficient use of space – Controlling growth keeps plants tidy and compact.
  • Higher quality fruit – Better sunlight and air exposure lead to higher sugar content and better flavor.

How to Prune Tomato Plants?

Follow these steps for pruning healthy, productive tomato plants:

1. Start pruning when plants are 12-18 inches tall.

This ensures they are established and actively growing. Use clean, sterilized pruners for best results.

2. Identify and remove suckers weekly.

Check where leaf stems meet the main vine. Suckers will appear as single-stemmed shoots. Snip them off cleanly at the base.

3. Gradually remove the lower leaves up to the lowest fruit.

Start by pruning just the 1-2 lowest leaves. Work upwards over time to improve air circulation.

4. Pinched off 3-4 inches from the top on indeterminate varieties.

Pinching the growing tip encourages more side shoots and fruit production. Do this once they reach 2-3 feet tall.

5. Remove any diseased or dead leaves immediately.

Check under leaves for pests too. Disinfect tools after any diseased pruning.

6. Avoid pruning determinate varieties heavily.

Only remove lower leaves and any damaged foliage. Don’t prune flowering or fruiting stems.

7. Prune flowering varieties less as the fruit develops.

Remove only new suckers and leaves shading fruit. Limit pruning to avoid stress.

Pruning and Supporting Tomato Plants

Supporting pruned tomato plants is just as important as pruning them. Use these guidelines:

  • Add tall stakes or cages when plants are 18-24 inches high.
  • Select support 7-8 feet tall for most indeterminate varieties.
  • Use strong metal posts or treated wooden stakes that won’t break.
  • Weave plant stems loosely through support openings as they grow.
  • Tie main leaders to supports using stretchable garden tape or twine.
  • Ensure supports are firmly anchored and won’t topple from wind or weight.
  • Prune as needed to train plants up supports and control width.

Properly pruned and supported tomato plants will yield bumper crops of beautiful ripe tomatoes! Just avoid common pruning mistakes and practice proper technique.

Key Tomato Growing Tips

  • Choose disease-resistant tomato varieties suitable for your climate. Early Girl, Celebrity, and Better Boy are popular options.
  • Start seeds indoors 6-8 weeks before the transplanting date. Use a seed starting mix and grow lights.
  • Harden off tomato seedlings first before transplanting. Gradually exposed to sun and wind over 7-10 days.
  • Transplant seedlings 18-24 inches apart in full sun once soil warms to 60°F or above.
  • Add supports or cages when transplanting. Stakes should be 5-7 feet tall for most varieties.
  • Use black plastic mulch and soaker hoses to conserve moisture and suppress weeds.
  • Apply a balanced vegetable fertilizer when transplanting and every 3-4 weeks thereafter.
  • Prune regularly to maximize fruit production and allow for airflow and disease prevention.

Tomato Gardening Supplies Checklist

  • Bypass hand pruners
  • Tomato cages or tall metal stakes
  • Trellis netting
  • Drip irrigation tubing or soaker hose
  • Granular fertilizer or soluble plant food
  • Liquid organic pest and disease control
  • Tomato clips for attaching vines to supports
  • Red plastic mulch
  • 5-gallon buckets for harvesting
  • Mesh bags for storing picked tomatoes

When to Prune Different Tomato Types?

Variety Pruning Method
Determinate Remove lower leaves only
Ace 55 Prune lightly until flowering
Early Girl Avoid cutting flowering stems
Roma Minimal pruning needed
Indeterminate Pinch and prune regularly
Beefsteak 2 weeks before the frost
Cherokee Purple Remove all suckers
Brandywine Top when 2-3 feet tall
Black Krim Use stakes or cages

Common Tomato Pruning Errors

  1. Over-pruning determinate varieties
  2. Leaving stubs when removing suckers
  3. Pruning plants when wet
  4. Using unsterilized tools between plants
  5. Removing too many lower leaves at once
  6. Not staking and topping indeterminates

Tomato Plant Pruning Tips

  • Start pruning when plants are 12-18 inches tall
  • Use clean, sharp bypass hand pruners
  • Remove suckers at their base as they appear
  • Gradually prune lower leaves up to the lowest fruit
  • Pinch off 3-4 inches from the top on indeterminates
  • Stop pruning determinates when flowers appear
  • Avoid heavy pruning in hot sun or high winds
  • Sterilize tools before pruning diseased plants
  • Add supports as needed to trellis-pruned plants

Leave a Comment