Blossom End Rot in Tomatoes: Prevention & Cures

Last update: 2021-09-23

Blossom End Rot in Tomatoes: Prevention & Cures

If one day, you find a yellowish-brown spot on the first flush of tomato fruits where the blossom once was and it appears watery, those are signs of blossom end rot - a common condition happening in tomatoes.

This problem is fixable, luckily. In this article, I am going to share with you everything about blossom end rot in tomatoes: prevention & cures. Keep reading!

How To Cure Blossom End Rot In Tomatoes

The good news is if your tomato plants have produced a few fruits already, there is still a way to save the plant and the remainder of this fruit-bearing season.

Discard All Affected Tomatoes

Blossom End Rot in Tomatoes: Prevention & Cures

Remove all rotten fruits to eliminate the affection.

Because blossom end rot is just a condition caused by a calcium deficiency, not by a viral, fungal, or bacterial issue, so you can put the affected fruits in your compost bin to recycle them.

Or, eat what’s left of the fruit.

If you intend to eat them, take note that the end rot tomatoes are usually of poor quality and mealy, which is only suitable for eating raw, not for preserving or canning.

Adjust Your Watering Habits

Blossom End Rot in Tomatoes: Prevention & Cures

As stated above, this condition is caused by a calcium deficiency but not in the soil, therefore, calcium sprays or amendments won’t help.

The actual cause is that your tomato plants cannot take up the calcium already existing in the soil due to improper watering habits. Therefore, simply by watering them evenly, deeply, and less regularly, you can fix the problem.

Below are some basic pieces of information regarding watering you must know:

  • The minimum amount of water per week required by tomato plants is 1”
  • Avoid not letting your plants go through droughts, even if it just lasts a couple of days
  • Consistency is key in watering tomato plants
  • Only water the plants early in the morning at ground level, not from above.

How to know if you provide enough water to your plants

You should measure the number of rainfalls that your tomato garden receives each week to decide to apply extra watering from a sprinkler or a hose.

Blossom End Rot in Tomatoes: Prevention & Cures

With sprinkler use, place an empty 1” tall can along the path of the sprinkler and near your plants. Once the can is fulfilled, that means you have provided the plants with the minimum amount of water needed.

The speed to fill a 1” tall can is different between sprinklers and you should take note of this issue to know when to turn off your irrigation system.


Blossom End Rot in Tomatoes: Prevention & Cures

This is an optional step but will help your affected plants because mulching helps retain moisture in the soil, along with providing nutrients over time and preventing weeds.

Surround each tomato plant, apply a 2” to 4” thick layer of wood chips, hay, or shredded newspaper.

Blossom End Rot in Tomatoes: Prevention & Cures

Non-Effective Treatments

As mentioned above, the calcium lacking in tomato plants isn’t derived from the calcium deficiency in the soil. Therefore, there's no need for fungicides or sprays. Those remedies involving milk sprays, crushed eggshells, or antacids aren’t effective in this case, either.

You should only apply them once a soil test tells you there is a true calcium deficiency in your garden soil.

How To Prevent Blossom End Rot In Tomatoes

Remain The Right Watering Habit

Blossom End Rot in Tomatoes: Prevention & Cures

Remaining appropriate watering habits for your tomato plants is an effective way to prevent blossom end rot.

Potted plants are prone to be drought rather than ones grown in earth ground, therefore, you should pay extra attention to them by following these tips:

  • Make sure the pot has a drainage hole and isn’t placed in a saucerful of water (to prevent waterlogging or overwatering)
  • Each pot should be 3-5 gallons incapacity
  • Remain the habit of watering your potted plants deeply every 2-4 days.

Avoid Over-Fertilizing

Blossom End Rot in Tomatoes: Prevention & Cures

It is recommended to fertilize tomato plants with a balanced organic granular fertilizer, seaweed emulsion, liquid kelp, fish emulsion, or compost at an appropriate amount.

Limit the use of synthetic chemical kinds, especially the ammonia-based nitrogen fertilizer because too many ammonium ions in the soil will interrupt the plant’s capability of taking up calcium.

Pay Attention To The Soil pH

Blossom End Rot in Tomatoes: Prevention & Cures

Since tomato plants are acid-loving plants, the ideal soil pH level for them is as close to 6.5 as possible.

You should periodically make a soil test – at the same time each year or at the same time every 3-5 years if manure is applied.

Frequently Check The Calcium Content In Your Garden Soil

It is recommended to check the soil nutrients manually. And, if you find your garden soil is lacking calcium, try calcium sprays, amendments, gypsum, or lime to the soil. If possible, combine with using a foliar spray.

Blossom End Rot in Tomatoes: Prevention & Cures


Do you find my post “blossom end rot in tomatoes: prevention & cures” was helpful to you? Have you applied any of the solutions that I listed above? I’d like to hear more from you, so please leave your thoughts and feedback in the comment section below. Thank you for reading!

Harry Ramos
Harry Ramos

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