blossom end rot
Organic Gardening

Blossom End Rot Treatment: How to Prevent Blossom End Rot

Learn about soil health, blossom end rot, what is it, how to identify it, and how to prevent it.

In your garden, you see a beautiful tomato forming. You marvel at its bright red, shiny skin. It’s perfect, you think to yourself and beam at your success of growing something so beautiful and perfect. Then you begin to imagine how you’re going to eat it.

Of course, at first it looks perfect, but on closer examination you notice the fruit stopped forming. The bottom of it is brown and bruised looking. Your heart slowly sinks. You quickly go online to do a search and discover it is blossom end rot.

What on earth is that?

There is nothing like freshly picked produce from the garden. It’s one of my fondest memories growing up. Check out my ‘About‘ page to see how/why I got started growing a garden. The taste and quality are unmatched by what’s found in the store. Store bought produce is meant to endure the long journey to stores across the country. The produce isn’t picked at its most optimal time in order to prevent spoilage.

While growing your own food, there are many successes and many failures. Fruit will not always look picture perfect, and that’s ok. We’ve become used to perfectly round tomatoes and perfectly shaped zucchini. That’s not what will always happen.

To ensure healthy fruit, it’s important to try to identify when there might be an issue with a plant that could affect many things: its growth, fruit production, etc.

A common occurrence in the garden is bruising, which doesn’t make your tomatoes look the prettiest.

This post is all about blossom end rot treatment.

What is blossom end rot?

Two tomatoes with blossom end rot
Blossom end rot on two tomatoes

Healthy roots are really important to grow healthy plants. The plant’s roots carry nutrients to grow and produce its foliage, flowers, and eventually fruit. Blossom end rot is not in fact a disease of the plant, but is actually a physiological disorder caused by a malabsorption of calcium. The bruising will appear where the blossom was at the bottom of the tomato as it is growing (see photo above). Tomatoes are not the only plant where this occurs though. It can also happen to other plants such as eggplants, squash, and peppers for the same reason.

How do you identify blossom end rot on your plant?

Identifying blossom end rot is really easy. It’s probably the easiest to identify. As the plant is growing, the bruising on the bottom of the fruit will become more and more apparent. At first it’s not noticeable when the fruit is smaller. It may be occurring if your area has gone without rain for some time, and you have not been consistent with watering your plants. It can also occur if plants become water soaked.

If my tomato has it, is it edible?

Blossom end rot is certainly not the most appealing thing to see on your fruit. Don’t worry though! The unbruised portion of the tomato is still edible, and the bruised part can just be cut off. It does not affect the rest of the tomato.

These tomatoes will not even make it to the shelf at a grocery store, even though it’s edible since customers look for picture perfect produce. It makes sense though because even I would want to know how that bruising occurred.  Being involved in growing your own food and having that connectedness to your food allows that. Shipping blemished fruit doesn’t ensure safe travels in-transit.

Healthy yellow squash growing on squash plant

What Causes Blossom End Rot and Blossom End Rot Treatment

The Causes

Healthy soil equals a healthy plant. Without the correct amount of nutrients in the soil, your plants will indeed struggle. Water is important too as it helps carry nutrients out of the soil, up the roots, and into the plant. Lack of nutrients whether from the soil or because of lack of water leads to unhealthy plants and can leave plants stunted, cause conditions that are not ideal to grow fruit, as well as a variety of other issues. In the case of blossom end rot, the plant has had inconsistent watering. Fluctuations between too wet or too dry can be taxing on plants. Damage to the roots impairs the plant’s ability to properly transport calcium up through the roots and throughout the plant. Over Fertilizing causes improper distribution of calcium. High humidity or low humidity coupled with hot, windy conditions prevent calcium from making its way to the fruit.

“Drought stress, alternating soil moisture extremes, and damage to a plant’s roots all can inhibit calcium uptake, as can waterlogged or cold soils, and high concentrations of ammonium (NH4+), potassium (K+), and magnesium (Mg++) cations in soil.”

Joy, Ann, hudelson, Brian. “Blossom end rot”. wisconsin horticulture division of extension. 1 APR 2005.

Preventative Tips

Test the soil

Testing the soil before planting allows you to see exactly what its deficiencies are. In knowing its deficiencies, you can amend accordingly.

  • When should the soil be tested?
    Test your soil in advance before anything is planted in case amendments are required. Amendments to the soil take time and don’t provide adjustments overnight. Test in the fall to see what your soil is lacking. If it’s lacking nutrients, put down your amendments so the soil’s ready for spring.

Check the pH level of the soil

Check out the pH level of the soil. It should be a pH of 6.5

Amend the soil

Amend the soil with fertilizers, calcium, and whatever else your soil may need.

  1. Keep a consistent amount of moisture in the soil with watering. Ideally, a soaker hose or drip irrigation system should be put into place. However, if that’s not possible, ensure the plants get a deep watering. Tomatoes typically need 1 to 2 inches of water per week.
  2. Apply mulch to your soil. There are various types of mulch that can be applied to your soil. Applying mulch helps to retain moisture in the soil, as well as prevent soil from washing away. Mulch is crucial during really hot weather and in drought situations.
  3. Before planting seedlings, ensure the soil temperatures have warmed up. Cold soil will limit the plants’ nutrient uptake.

Frequently Asked Questions (FAQ)

Here are some questions that may help you further understand dealing with blossom end rot:

  1. Can you stop or reverse blossom end rot?

No, unfortunately once a plant’s fruit has blossom end rot, you won’t be able to get rid of it. You can try to save the rest of the plant and fruit. However, I have not found success with trying to prevent it with future fruit developing once you’ve already spotted it on the plant. Depending on the amount of rot, you can either cut away the damage and still eat the fruit, or compost it. Since blossom end rot isn’t a disease, it’s ok to add the fruit to your compost pile.

  1. Should you keep the fruit on the plant if you notice blossom end rot?

You can pick any affected fruit off of the plant. There’s no way to get rid of blossom rot on the fruit once it presents itself. As mentioned previously, you can still eat the fruit as it’s totally safe. Simply cut out the blackened area. 

Let me know if you have any other specific questions about blossom end rot and I’ll be sure to add them to this growing list.


Let’s recap what we’ve learned in this post about blossom end rot:

  • Blossom end rot is a physiological disorder that’s created from a lack of calcium. A lack of calcium can be caused by a number of environmental/growing conditions. It’s a very common occurrence in the garden so it’s good to know what it is and how to identify it.

  • Once your plant has blossom end rot, you won’t be able to get rid of it. The best plan of action is to prevent it from happening. If your plant gets it, it’s not the end of the world. The fruit is still edible.

    • We discussed testing the soil to see what nutrients it’s lacking and to check the pH level, amending the soil and examples of what you might consider using, consistent watering, applying mulch to retain moisture levels, and planting at the correct temperatures.

I hope this has helped you learn enough about blossom end rot to feel comfortable and confident to identify it and determine what’s happened to your plants!

This post is all about blossom end rot treatment.

Leave a Reply

Your email address will not be published. Required fields are marked *