Tomatoes rotting or blossom end rot is a common gardening problem that has caught many new gardeners off guard. Whether on tomatoes, melon fruits, cucumber, pepper or squash, you may come across blossom bottom end rot.
This guide focuses on preventing and treating tomato blossom end rot and stop your delicious tomatoes rotting on your vines.
There are few greater pleasures than harvesting stunningly red and plump tomatoes and other crops from the vegetable garden you’ve cultivated all on your own.
Especially, when you’ve taken extreme care to plant and care for your tomatoes. However, if you’re a first-time grower, you may notice a rot on some of your fruit.
Tomatoes Rotting or Blossom End Rot: How to Treat & Prevent?
There are a variety of garden fruits and vegetables that are particularly susceptible to tomato blossom end rot. Here’s a quick guide to identifying, treating and preventing tomato bottom rot in your garden.
What is Tomato Blossom End Rot?
Tomato blossom end rot is a common garden problem, but not actually a disease from which your plants suffer. This physiological disorder arises from a calcium imbalance within your plants.
Container plants seem to be particularly susceptible to tomato bottom rot. Luckily, while you won’t be able to cure infected fruit, blossom end rot can be stopped once it starts.
Identifying Tomato Bottom Rot
Tomato bottom rot will begin to show signs only once your fruit begins to ripen. You will notice a leathery brown sphere forming at the base, or bottom-end, of your fruit.
Appearing almost like a dark bruise, the brown area will expand as the fruit continues to rot.
What Causes Tomato Rot?
Tomato bottom rot is not caused by the lack of calcium within the soil, but rather your plant’s inability to absorb the calcium. This is many times aggravated by over watering.
Common causes of root rot include:
- Soil Fluctuations. Including moisture, nutrient balance and temperature.
- Excess Nitrogen. Many fertilizers are nitrogen rich and can cause an imbalance.
- Root Damage. This can occur when re-planting or when treating soil.
- Incorrect Soil PH. Your plant may struggle when soil is particularly acidic or alkaline.
- Cold Soil. Especially during planting, if soil is particularly cold root ends may die off.
- Salty Soil. If the soil is particularly salty it will affect your plants ability to absorb nutrients.
How to Fix Blossom End Rot?
Should you discover that your fruits are beginning to bear signs of tomatoes rotting, it’s important to take swift action to prevent more of your plant being affected by the rot.
Follow these 3 simple steps to help you manage and fix your tomato blossom end rot problem:
Step One
- Carefully remove all infected fruit with a sharp pair of gardening shears.
(Check out our compilation of the best secateurs available for 2023). - You can make a simple cut at the stem of your fruit.
Step Two
- Support your plant with additional calcium.
- You can either add some crushed eggshells to the soil, or water with powdered milk, which seems to be the more effective option.
- Mixing powdered milk into watering can will help give your plant a quick and solid hit of calcium which it so desperately needs.
Step Three
- Monitor your watering.
- The biggest key is to keep your watering consistent.
- Blossom end rot can be caused by overwatering and underwatering, so proper moisture maintenance is key.
Step Four
- Add a layer of mulch surrounding your plant of about 2 to 4 inches.
Be conscious not to suddenly add copious amounts of fertilizer to your soil, as this may have an adverse effect.
How to Prevent Tomato Bottom Rot
As they say, “Prevention is better than treatment,” and the same applies to tomato rot. Here are a few ways that you can prevent tomato rot in your garden:
- Add Tomato Root Stop to the soil.
- Maintain your soil moisture levels. After watering, moisture should sit as deep as 6-inches, especially in dry climates.
- Make use of low-nitrogen, high-phosphorus fertilizers and fertilize primarily in the summer months. Be sure not to over fertilize.
- Regularly test your soil and try to maintain a pH level as close to 6.5 as possible. (Learn how to adjust you soil's pH here).
- Occasionally add mulch and components high in lime or calcium to your soil.
What is the Fastest Way to Add Calcium to Your Soil?
The easiest and cheapest ways to add calcium to your soil to prevent tomato rot are with eggshells, Epsom salts or soil additives.
1. Supporting Your Plants with Eggshells
Eggshells carry a lot of calcium. Keep your eggshells and allow them to dry out. Once dried, place them into a blender and blend until it becomes like a white powder, similar to that of coffee grounds.
Using your garden trowel or hands mix the eggshell mixture into your soil. It is recommended to enrich your soil with eggshells at least two weeks before planting.
For some plants it can take anywhere between 6 to 12 months to actually absorb the nutrients from the eggshells.
2. Adding Epsom Salts To Your Plants
Epsom salts have long been known to be a beneficial additive for a variety of plants. While you don’t want to over-salt your soil, an occasional Epsom salt watering can do wonders for plant absorption.
Mix one tablespoon of Epsom salt into about 1 gallon of water. Apply the mixture to your plants every couple of weeks.
3. Mixing Soil Additives To Your Plants
Amazon offers easy-to-use soil test kits that can tell you exactly what your soil needs more or less of. When it comes to your pH levels, Gypsum and lime are the most common soil additives used.
There are plenty of soil additives available (click here for reference on soil additives) specifically formulated to keep your tomato plants happy and rot-free.
Adding coffee grounds, tea-bags and banana peels are also great ways to support your soil with some extra nutrients and have been known to support nutrients absorption in tomatoes.
Tomatoes Rotting Frequently Asked Questions
Should I remove tomatoes with blossom end rot?
You should always remove tomatoes with blossom end rot when you see them. Blossom end rot will continue to develop on fruit that is left on the vine, and wastes the energy of the plant.
If you notice blossom end rot on ripe fruit, you can simply cut the affected part off. The rest of the fruit is fine to eat.
Does blossom end rot spread?
Blossom end rot does not spread from fruit to fruit, and just because one plant has it, does not mean its neighboring plant will develop the same problem.
Calcium imbalances can vary from inch to inch in the soil depending on the fertilizer you use, how you water, and drainage. Focus on plants that are showing signs, rather than treating every plant, which risks overfeeding, or over calcifying.
Does overwatering cause blossom end rot?
Over-watering does not cause blossom end rot, but it does contribute to it. The cause of blossom end rot is a lack of calcium, or an inability to take in calcium.
Over-watering dilutes and flushes nutrients (including calcium) from the soil, which in turn, increases the chance of blossom end rot. So while overwatering isn’t the leading cause, it is worth avoiding it!
Can you put too much calcium on tomatoes?
Tomatoes can be overfed with calcium, and many shop bought tomato feeds contain calcium as standard. However, if you are feeding regularly but still seeing signs of blossom end rot, it’s worth adding gentle calcium to the soil in the form of eggshells, which release calcium slowly and evenly to avoid putting too much calcium on.
Does milk help with blossom end rot?
Milk is an obvious solution for blossom end rot as it contains high amounts of calcium, and is in liquid form, which makes it readily available, but, it also contains huge amounts of lactose sugars, and fats, making it a very, very, bad idea to feed outdoor tomatoes with it.
Milk will attract vermin, and promote the exact conditions to root rot. The same goes for milk powder. Just don’t do it.
How often should tomatoes be watered to avoid blossom end rot?
To avoid blossom end rot, water tomatoes only when the surface of the soil appears dry. Overwatering can flush nutrients and calcium from the soil and increases the risk of blossom end rot.
For outdoor tomatoes in warm climates, water every two to three days. For greenhouse tomatoes, water them every one to two days.
How Do You Stop Tomato Rot?
Again, once your fruits begin to rot, there is very little for you to do to save them. This, however, doesn’t mean your entire plant will be wasted. The problem of tomato rot can be treated and most importantly, prevented with proper care.
Can I Eat a Tomato with Blossom End Rot?
The answer is quite simply, yes, but no. While consuming rotten fruit isn't dangerous, it may be highly unpleasant. You can cut away the rotten bit to salvage the fruit, it is mostly recommended to simply dispose of any fruit affected by tomato blossom end rot.
Wrapping Up Our Guide to Tomatoes Rotting Treatment and Prevention
When it comes to tomato rot the most important factor is to identify it early and start actioning treatment against it. Some infected fruit won’t spoil the whole plant, so be sure to cut away rotten fruit and continue to care for your plant.
With the proper care, you can have beautiful fruit bearing tomato plants without the worry of tomatoes rotting.