Blossom End Rot in Tomatoes
Gardeners look forward to picking the first ripe tomato of the season. But sometimes those first tomatoes have soft brown or black leathery spots covering the bottom of the fruit.
How disappointing!
This tomato affliction is called blossom end rot. The good news is that blossom end rot does not spread from one plant to another, nor does it affect the plant itself and in most cases it is preventable.
Blossom end rot is typically seen early in the season and often doesn’t affect fruit that is set later in the summer. It is caused by a poor supply of water and calcium in the developing tomatoes.
Tomato plants that were planted out in the garden before the soil warmed up are susceptible to blossom end rot because their root systems don’t develop well in cold soil. Without a good root system the plants cannot take up enough moisture and calcium for the developing fruit, resulting in blossom end rot. Blossom end rot may also be a problem after dry periods followed by heavy rains.
Mulching your tomato growing bed after the soil has warmed up is a good way to prevent blossom end rot as the mulch helps to maintain even moisture in the soil. You’ll also want to keep the plants well watered during dry periods and avoid cultivating too closely to the plants as this can disturb tiny feeder roots that are close to the surface.
If you have tomatoes afflicted with blossom end rot, just remove those fruits from the plant, maintain even moisture for your plants and wait for the next set of tomatoes to ripen.
Have a great week!
-Mike McGroarty
I have very sandy soil here in Irondequoit NY. 60 feet deep. I couldn’t grow tomatoes or zucchini and I tried adding calcium and I tried epsom salts. What I learned was the problem is uneven water. Water passes through the plant and takes the calcium all the way through to the blossom end. The answer is to mulch. Add whatever calcium supplement you want- I used powered oyster shell that they feed to chickens. I also put in a 3/4″ PVC pipe with holes drilled into it- that’s under the mulch so the water doesn’t touch the plants preventing fungus problems. The water soaks into the soil under the mulch keeping a constant supply of moisture available- Ive not lost one tomato or squash since I did this. Just adding calcium won’t solve the problem as no matter how much you add you need water to move it through the plant.
When planting tomatoes, we put a Tums tablet on either side of the planting hole.
You can fix and stop it without having to buy a thing. I had it so bad that I was just about to quit growing tomatoes. I talked to a older man about 20 years ago and he told me to put grass clippings or straw under plants. To this day I have not had it again. I read a thing the other day that Epson salts does nothing to help plants, from a collage and I can not remember where I read it. They did a 5 year study and they said treated with epson or not treated , there was no difference in yield, plant size or keeping bugs away.
I have added crushed eggshells to the soil with good success, but I seem to have something of the same problem with my squash. Any suggestions?
Equal parts of powdered milk and Epsom salts–calcium and magnesium. Sparsely every two weeks into the soil.
Blossom end rot can also be corrected with a super cheap bag of crushed limestone, 50 lbs at $5. Since this is not a fertilizer you cannot overdose it. Add a generous amount in and around the planting hole. Also add more Limestone throughout the season. Compare this to the over the counter stuff especially the spray on and the money saved will plant an extra row.
I grind up egg shells in a blender until they are powder and dig them into the soil where I’m planting tomatoes. No more blossom end rot.
You can also sprinkle some powdered lime around the tomatoes to increase the quantity of calcium available to the tomato plant.