Blossom RotDiseaseTomato Plants

Why Does My Tomato Have Blossom End Rot?

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Quick Facts About Tomato Plants and Blossom End Rot

Key PointsDetails
Scientific Name:Solanum lycopersicum
Growing Conditions:Prefers well-drained soil and ample sunlight.
Reason Why Tomato Blossom End Rot:Blossom end rot is a sign of calcium deficiency in the developing fruit.

Tomatoes are a popular choice in gardens and a go-to ingredient in cooking, whether you’re making salads, sandwiches, or pizza sauce.

But what should you do if your well-loved tomato plants produce fruits that have blossom end rot? 

Is there a way to fix it?

In this article, we’ll explore why tomato end rots and I will offer some simple solutions that you can do to prevent it in the future. 

Let’s get started!

What Exactly is Tomato Blossom End Rot?

Blossom end rot is a common disorder in tomatoes that causes dark, sunken spots to form at the blossom end of the fruit—the part opposite the stem. 

Many people believe this issue is caused by disease or insects, but it's not. 

Blossom end rot is actually a physiological problem that results from a calcium deficiency in the developing fruit.

Even though most soils are already calcium-rich naturally, various factors can prevent this nutrient from reaching the parts of the fruit where it’s needed most. 

And since Calcium is crucial for cell structure and strength. When certain areas of the fruit don’t receive enough, the cells will collapse, leading to those familiar leathery spots.

Inconsistent Watering

One major factor that leads to this condition is water stress or inconsistent moisture levels. 

When tomato plants don't receive a steady supply of water, the flow of nutrients, including calcium, to the developing fruits is disrupted. 

This can happen when the soil alternates between being too dry and too wet, causing the plant to prioritize sending nutrients to the leaves over the fruits. 

As a result, the fruits are deprived of the calcium they need, which can lead to the development of blossom end rot.

Excessive Use Of Fertilizers Rich In Nitrogen

Additionally, excessive use of nitrogen fertilizers can disrupt the plant’s ability to transport calcium to the fruit, triggering blossom end rot. 

High levels of nitrogen encourage rapid vegetative growth, causing the plant to produce more leaves and stems. 

This increased leaf growth demands more water, which in turn pulls calcium away from the developing fruits. 

As the plant directs more resources to the leaves, the fruits are left with insufficient calcium, leading to the characteristic symptoms of blossom end rot. 

Can My Tomatoes with Blossom End Rot Be Saved?

When you discover that your tomatoes have blossom end rot, it can be disappointing. 

But the good news is, that not all is lost. In many cases, you can salvage the affected tomatoes with a few simple steps.

First, if the rot is confined to a small area of the fruit, you can simply cut away the damaged portion. While the remaining part of the tomato is still edible and can be used in cooking or eaten fresh. 

You can do this by removing the affected area quickly before secondary infections or mold sets in, which could render the entire fruit inedible.

Lastly, while affected fruits can’t be cured, focusing on the plant’s care can stop blossom-end rot from spreading to new fruits. 

What you can do is regularly check your plants, especially during critical growth periods, to ensure that they are receiving consistent care. 

Managing it properly can reduce the likelihood of future fruits being affected.

Common Misconceptions About Blossom End Rot

Blossom end rot is a well-known issue among tomato growers, so it’s not surprising that several myths and misconceptions exist about how to prevent or treat it. 

Here are three common myths that often circulate, along with explanations of why they don't work.

Myth 1: Putting Tums Tablets at the Bottom of the Tomato Plant

One popular myth is that placing Tums or other calcium-rich tablets in the soil at the base of a tomato plant can prevent blossom end rot. 

The idea here is that the calcium in the tablets will be absorbed by the plant and prevent the deficiency that causes blossom end rot. 

However, this method is ineffective. 

Because the problem with blossom end rot isn’t a lack of calcium in the soil but rather the plant's ability to transport calcium to the developing fruit. 

The roots of the plant need to take up calcium from the soil, and this process relies on consistent watering and proper soil conditions, not on adding calcium tablets directly to the soil.

Myth 2: Putting Crushed Eggshells in the Soil

Another common misconception is that adding crushed eggshells to the soil will prevent blossom end rot by providing a source of calcium. 

While it’s true that eggshells contain calcium, the form of calcium they provide isn’t readily available to plants. 

Eggshells decompose very slowly, and it can take years before they break down enough to release calcium into the soil in a form that plants can use. 

If you want immediate results, consistently watering your plants and practicing proper soil management are far more effective than relying on eggshells.

Myth 3: Using Epsom Salt

Some gardeners believe that adding Epsom salt to the soil can help prevent blossom end rot. 

Epsom salt is magnesium sulfate, and while magnesium is an essential nutrient for plants, it doesn’t prevent or cure blossom end rot. 

In fact, adding too much magnesium can create an imbalance with calcium, potentially making the problem worse. 

To reduce the likelihood of having a blossom end rot in your tomatoes, focus on keeping calcium levels steady and watering regularly, rather than adding magnesium to the soil.

How Can You Prevent Blossom End Rot in Your Tomatoes?

Avoiding blossom end rot requires a proactive approach to tomato care. 

Practices like consistent watering, using balanced fertilizer, monitoring soil pH levels, and avoiding overloading your plants with fruit will help prevent blossom end rot. 

By focusing on these key practices, you can significantly reduce the likelihood of this issue affecting your plants.

Maintain Consistent Watering

Ensuring that your tomato plants receive deep and regular watering is essential for preventing blossom end rot. 

But how do you know if you've watered deeply enough? 

A good rule of thumb is to water the soil until it’s moist at least 6-8 inches below the surface, which is where the plant’s roots are primarily located. 

You can check this by sticking your finger or a small trowel into the soil to feel the moisture level. 

And if the soil feels dry a few inches down, it’s a sign that your plants need more water. 

Regular watering typically means giving your plants a thorough soak once or twice a week, depending on your climate and soil type, rather than frequent light watering, which can lead to shallow root growth.

Maintain Consistent Moisture Levels

To further prevent blossom end rot in your tomatoes, another important step is to apply mulch around the base of the plants. 

Mulching is beneficial no matter where you’re growing your tomatoes—whether in the ground, in pots, or in raised garden beds. 

However, there are a few specific considerations to keep in mind for each growing method.

In the Ground

When planting tomatoes directly in the soil, you will need to apply a 2-3 inch layer of mulch to maintain consistent moisture and regulate soil temperature. 

Mulch helps protect the soil from drying out too quickly which is highly like when planting your tomato plants, especially during hot weather. It also reduces the need for frequent watering since mulch slows down the evaporation process, allowing the soil to stay moist for a longer period of time. 

In Pots

When you’re planting tomatoes in pots or containers, it may require slightly more attention when it comes to mulching.

Since containers tend to dry out faster than garden beds due to the limited soil volume and increased exposure to sun and wind. A 2-3 inch layer of mulch is still recommended, but you might need to monitor moisture levels more frequently.

Watering may need to be done more often, and the mulch will help to keep the soil from drying out between waterings.

In Raised Beds

Similar to in-ground planting, a 2-3 inch layer of mulch works well for tomatoes in raised beds. 

Raised beds often have better drainage, but they can also dry out faster, especially if the beds are elevated off the ground. Mulch helps to retain moisture and maintain more consistent soil conditions, which is crucial for preventing blossom end rot.

In all cases, ensure that the mulch is not piled directly against the stem of the tomato plants, as this can lead to stem rot. Always leave a small gap around the stem to allow for air circulation. 

Use Balanced Fertilization

Another thing you can do to prevent your tomatoes from having blossom end rots is to fertilize your tomatoes correctly.

And one of the key things to avoid is the excessive use of high-nitrogen fertilizers, which can promote rapid leaf growth at the expense of fruit development. 

When tomato plants receive too much nitrogen, they focus their energy on producing more leaves rather than fruits, which can lead to a nutrient imbalance and increase the risk of blossom end rot.

High-Nitrogen Fertilizers and Their Effects

High-nitrogen fertilizers, such as urea, ammonium nitrate, and ammonium sulfate, are commonly used to boost plant growth. 

For instance, urea is a widely available nitrogen source that can quickly enhance leaf production. 

While ammonium nitrate, known for its rapid-release properties, also encourages fast vegetative growth. 

And ammonium sulfate provides both nitrogen and sulfur, but if used excessively, it can cause too much leaf growth and not enough fruit production. 

While these fertilizers can be beneficial in moderation, using them in excess can disrupt the plant’s natural balance and hinder fruit development, making it more susceptible to issues like blossom end rot.

Balanced Fertilizers for Tomato Plants

Instead of relying on high-nitrogen fertilizers, it’s better to use a balanced fertilizer that provides essential nutrients like nitrogen, phosphorus, and potassium in the right proportions. 

Balanced fertilizers, such as 10-10-10, 20-20-20, or 15-15-20, will support overall plant health and promote fruit production. 

For example, a 10-10-10 fertilizer contains equal amounts of nitrogen, phosphorus, and potassium, making it a good all-purpose choice. 

While a  20-20-20 fertilizer offers a higher concentration of these nutrients, which can be helpful during periods of vigorous growth and fruiting. 

And the 15-15-20 formulation has a bit more potassium, which can be particularly beneficial for tomatoes, as potassium helps regulate calcium uptake, further reducing the risk of blossom end rot.

In addition to these synthetic options, natural and organic fertilizers can also provide a balanced nutrient mix that benefits tomato plants. 

  • Compost is an excellent choice, as it is rich in organic matter and provides a slow-release source of nutrients that improve soil structure and fertility. 
  • Worm castings are another highly nutrient-dense organic fertilizer, packed with essential minerals that promote healthy plant growth. 
  • Bone meal, which is rich in phosphorus, supports strong root development and can be particularly beneficial during the flowering and fruiting stages. 

These organic options will enhance the soil’s overall health, supporting the growth of your tomato plants and reducing the likelihood of blossom end rot.

Ammonium-Based Fertilizers

Another important aspect of fertilization is to avoid ammonium-based fertilizers, as they can interfere with calcium absorption in tomato plants. 

Two common examples of this are ammonium nitrate and ammonium sulfate. 

When you use this fertilizer in large amounts, it can disrupt your plant’s ability to take up calcium, leading to calcium deficiency disorders like blossom end rot. 

To ensure healthy fruit development, it’s better to choose fertilizers that provide nitrogen without compromising calcium availability.

Regularly Monitor Soil pH

Aside from fertilizing your tomatoes correctly. Another thing you can do to prevent blossom end rot in your tomatoes is to make sure the nutrient availability in your soil, including calcium by testing it’s soil pH.

To do this, you will need to regularly test your soil’s pH using a simple pH testing kit, which you can find at most garden centers or online. 

These kits will allow you to quickly check whether your soil falls within the ideal range of 6.5 to 6.7. 

And if the pH is too acidic or too alkaline, you can adjust it by adding ground limestone (soil sweetener) to the soil or add sulfur to lower it.

This will create an environment where calcium can be effectively absorbed by your tomato plants. 

Additionally, you can also add organic matter to your soil like compost or well-rotted manure to gradually stabilize pH levels. 

For acidic soils, you can use wood ash to raise the pH, while peat moss can help lower it if the soil is too alkaline. 

Regular testing of the pH level of your soil and adjusting it accordingly will help maintain the optimal conditions for a healthy tomato growth.

Avoid Overloading Plants with Fruit

The last thing you can do to prevent having blossom end rot in your tomato is to avoid overloading your plants with fruits.

When a tomato plant bears too many fruits at once, it may not be able to supply adequate nutrients, particularly calcium, to all of them. 

This is especially true during periods of rapid growth when the plant's energy is spread thin. 

To help your plant manage its resources better, consider pruning some of the early fruit clusters. To do this, here are different ways how you can properly prune the early fruits of your tomato plants:

  1. Identify the Early Fruits: Early in the season, you would need to identify the first few clusters of tomatoes that begin to develop. These are typically the fruits that appear low on the plant.
  2. Choose Which Fruits to Remove: The next thing you can do is to select a few fruits from these early clusters that are smaller or less developed. Removing these will reduce the overall load of your plant.
  3. Use Clean Pruning Tools: When removing the early fruits that you choose, always use clean, sharp pruning shears or scissors to make precise cuts. This will help prevent the spread of disease (in case there is) and ensure a clean cut that will heal quickly.
  4. Cut Close to the Stem: Another thing you would need to do is carefully cut the chosen fruits at the stem. Always make sure to cut close to where they connect to the plant, without damaging the main stem or other developing fruits.
  5. Monitor the Plant: After pruning, always monitor the plant to ensure it continues to grow healthily. The remaining fruits should start to receive more nutrients and grow more robustly.

By following these steps, you can effectively reduce the burden on your tomato plants, helping them manage their resources more efficiently and reducing the risk of blossom end rot in the remaining fruits.

Now You Can Avoid Having Blossom End Rot In Your Tomatoes

Blossom end rot is a common issue that frustrates most tomato growers, but it’s a problem that can be effectively managed by being proactive.

By understanding that the root cause is often a calcium deficiency due to inconsistent watering or nutrient imbalances, you can take proactive steps to prevent it. 

How do you avoid having blossom end rot in your tomatoes? Share it in the comments below.

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