Preventing Blossom End Rot In Your Hydroponic Garden

It’s a common problem for soil and hydroponic gardeners alike. One day you have some beautiful green tomatoes, the next day you notice some spots on the fruit. Maybe you go to pick a ripe red tomato only to find the bottom sunk in and discolored.

Your fruit has blossom end rot, so what’s next?

First, What is Blossom End Rot?

Blossom end rot is a physiological disorder that affects the fruit of a plant. It’s caused by a deficiency and not due to pests or pathogens. Blossom end rot does leave the fruit open to invaders like mold and other pathogens to grow.

Spots start to form on the bottom of the fruit at about a third of the way through growth. As the fruit grows, so does the spot, often becoming sunken in. There’s no way of curing it wants it starts. While unappealing, the bad part could be removed after harvest and the rest of the fruit eaten. I prefer to remove it and correct the issue going forward.

Blossom end rot is common in tomato and pepper gardens but also can occur with squash, cucumber, melons, and eggplants as well.

What Causes Blossom End Rot In Hydroponics?

The quick answer? Calcium deficiency is the cause of blossom end rot.

When we think of calcium we often think of our bones. Calcium isn’t just necessary for skeletons, it’s also important to plants. Calcium plays a major role in the health of a plant’s cell walls and membrane. Healthy cell walls mean strong plants.

The important thing to find out is why your garden is having a calcium deficiency issue.

Why Isn’t Calcium Reaching The Fruit?

If you’re using a well-balanced nutrient regimen, then you will need to consider other reasons you may be having a calcium deficiency. The main cause of calcium deficiency is nutrient transport issues. Something is stopping your plant from taking in the needed calcium through the root system and transporting it to the fruit. Other issues may arise that affect the plant’s health, then lead to end blossom rot.

Root Problems- Roots that are damaged or diseased cannot take nutrients out of the nutrient solution, leading to deficiency.

Environmental Factors- High humidity, temperature, and general stress can cause nutrient transport issues.

Unbalanced pH- Plants can only take in nutrients while in a certain pH range. Outside that range and plants have nutrient transport issues

Add A Calcium Supplement To Your Hydroponic Garden

Adding supplements to your nutrient regimen can increase the overall health of your plants, preventing issues from arising.  Cal-Mag is a great calcium, magnesium, and iron supplement that can be mixed into your nutrient solution or used as a foliar spray for fast application. In addition to preventing end blossom rot, it also prevents tip burn in lettuce and cabbage, stunting, and leaf curl.

It’s easy to use, add 5-10 ml/gal when mixing your nutrient solution, depending on the stage of growth, up until a couple of weeks before harvest. For foliar use, add 15 ml/gal and adjust the ph to 6.2-7.0 before use.

Do you have any tips for dealing with blossom end rot in your hydroponic garden? Let us know in the comments!