7 Reasons Why Your Tomatoes Are Very Small + Effective Solutions

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Quick Answer: Why Are My Tomatoes Very Small?

The main reason for smaller tomato fruits is the stressed plants. It may happen under different circumstances, including lack of water, high temperature, heavy shading, root damage, excessive fertilization, mislabelling of plants, and poor pollination. You may prevent the problem by watering consistently, providing some protection during high temperatures, using appropriate fertilizers, and assisting in pollination.

Are you wondering why your tomatoes are so small? If yes, this guide will highlight some causes and easy-to-implement solutions.

I have faced and solved this problem while growing tomatoes in my home garden. I have also incorporated the views of other gardeners. 

Scroll down to know more!

Why Are My Tomatoes Very Small? And Solutions

The stressed tomato plants may produce undersized fruits. It may be due to lack of water, changes in temperature, root damage, excessive fertilization, poor pollination, pest attack, or disease infestation.

Tomatoes are the most popular fruits to grow in my home garden. The standard size for the beefsteak greenhouse tomatoes is eight to ten ounces.

During my first attempt at growing tomatoes, I had a problem with undersized tomatoes. It is disheartening to put in lots of effort and get small tomatoes.

Ao, why are sometimes tomatoes so small? 

The tomato plants experience stress under the circumstances, including extreme drought, insect infestation, high heat, or perpetuation of blight diseases. Such plants will focus more on survival than on producing fruits. They may yield small fruits.

There are many other possible reasons for your tomatoes to be small. Some of the causes of undersized tomato fruits are

  • Lack of water
  • High temperature
  • Heavy shading
  • Root damage
  • Mislabeling of tomato plants
  • Lack of pollination

Now we get deep into these causes and steps to avoid undersized tomatoes

1. Lack Of Water

When the tomato plants do not receive sufficient water, they may develop undersized fruits. Water the plants consistently and regularly to avoid the problem. Mulch around the plants to retain moisture.

One of the important causes for smaller tomato fruits is the lack of water. It may happen due to drought or improper care. The tomato fruit may not grow to full size.

Eventually, the whole plant will wilt and die.

What You Should Do?

Take care to keep the soil moist, and soak the soil thoroughly. Maintain a regular and consistent watering schedule.

Also, watering in the morning gets evaporated by the afternoon and reduces the incidence of diseases.

A general rule of thumb is to provide one to two inches of water per week for tomato plants. You may use a trowel to see if the soil is wet. Sandy soils may need more watering.

I prefer to grow tomatoes in self-watering containers so that there is proper soil moisture throughout the growing season and ensures full-sized fruits.  

I use organic mulch around tomato plants to retain moisture and regulate temperature. I was surprised that watering consistently increased fruit size in tomatoes.

2. High Temperature

High temperatures may limit the size of tomato fruits. Provide some protection in the afternoon if living in a hot, humid climate.

Tomatoes grow at moderate temperatures between 65 to 85oF. High temperatures may cause delayed flower and fruit sets.

The Colorado state extension mentions that tomato fruit may not increase in size at temperatures over 95oF.

Delayed flowering and fruiting mean less energy to produce full-sized fruits. Likewise, low temperatures may also affect fruiting.

What You Should Do?

It is necessary to provide some protection if the plants are exposed to high heat.

I prefer to shade my plants in the afternoon as I live in hot and humid areas.

3. Heavy Shading

Excessive shading during the cloudier months produces smaller fruits as tomato plants require long hours of sunlight. Provide enough spacing between plants and avoid shading.

Tomatoes require at least six to eight hours of sunlight per day. They may not be productive if they receive less than optimum sunlight.

Excessive shading during the cloudier months may prevent the full development and cause smaller fruits.

Also, if your tomato plants grow in an area that is partially shaded, they will not grow to their full potential nor set full-sized fruits.

What You Should Do?

Take care not to shade the plants with large trees or tall buildings.

Provide enough spacing between plants and prune them so that they receive enough sunlight.

4. Root Damage

The damage to roots during transplanting or inserting support may affect the fruit development. Take care while transplanting to prevent the damage.

Tomato plants have delicate root systems.

You may damage the roots while transplanting. It may cause stunted growth and poor development of fruits.

What You Should Do?

The roots may also be damaged while inserting stakes or cages into the ground. You may insert the stakes before transplanting to avoid damage.

5. Mislabeled Plants

The accidental mislabelled plants may be one of the reasons for producing smaller tomatoes. Purchase the seedlings from a trustworthy nursery to avoid the mistake.

Sometimes, the plants may be mislabelled at the nursery or mixed up for smaller-sized fruits. You may have accidentally switched the labels.

Different varieties produce different-sized tomatoes. For example, If you have grown cherry tomatoes instead of beefsteak tomatoes, you may get smaller fruits.

What You Should Do?

Next time, make sure you buy the seedlings from a reputable store to avoid mislabelling.

Few gardeners prefer starting from seeds rather than purchasing the seedling. It gives you time to familiarize yourself with the nature of the plants.

6. Excess Fertilization

Excessive nitrogen application may cause lush vegetative growth but produce smaller, tasteless tomatoes. Use appropriate fertilizers.

Nitrogen is one of the vital nutrients required for the growth of tomato plants.

The application of high nitrogen fertilizers may promote green leafy foliage but may lead to small and tasteless tomatoes.

What You Should Do?

So, avoid using high-nitrogen fertilizers for the tomato plants. Do not use low-quality fertilizers that may affect the tomato fruit size.

7. Poor Pollination

Poor pollination may affect the size of the tomatoes. You may shake the pollen using your hand and assist in pollination.

Tomatoes are self-fertile and have both male and female flowers within the same flower. They need biotic and abiotic agents to help in pollination.

High humidity may cause problems in releasing the pollen. In low humid areas, there may be difficulty in sticking the pollen to the female part of the flower.

Poor pollination may cause no or smaller fruits. Wild varieties are more susceptible to undersized tomatoes than hybrids.

What You Should Do?

If there is poor pollination, your seed count may be less. You may cut the fruit left to right and check if the locules have lesser seeds.

In such cases, the tomato plants may need help in increasing pollinatory activity. You may try hand pollination techniques or use a motorized toothbrush.

Here is a quick hand pollination guide for tomatoes –


What are the different reasons for stressing tomato plants?

The stressing of the tomato plants may be caused due to known or unknown reasons. Some of the possible causes are sudden changes in temperature, pest attack, or an incidence of a disease. It may cause stunted growth of plants or affect fruit yield.

What can I feed my tomato plants to get bigger fruits?

Tomato plants need a good starter fertilizer. You may feed your plants with phosphorus at blooming time. Pinch off one or two tiny tomatoes so that all of the plant’s energy goes into the remaining tomatoes. It may result in super-sized tomatoes.


I hope now you have a better idea about what causes small tomatoes in your garden.

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