With tomato harvest season in full swing, many gardeners will be picking their tomatoes ready to enjoy in a summer salad, blended up into a sauce or roasted for a soup. However, some gardeners may notice their tomatoes have developed a dark, sunken spot at their base, making them look particularly unpleasant. If your tomatoes have a large dark spot at the base of them, this is what is known as blossom end rot. The physiological disorder is caused by calcium deficiency.
Tomatoes with blossom end rot are safe to eat if you cut off the affected area but this does mean you end up wasting a lot of your tomato. To avoid blossom end rot, gardeners from the Facebook group, Gardening UK Hints, tips & advice have shared a kitchen scrap they recommend adding to their tomato plants’ soil: eggs shells.
The advice came to light after Eleanor Carroll discovered her tomatoes had blossom end rot and posted a picture of them on the Facebook group.
Clair Bate replied to the post: “Eggshells in the planter.”
Cheryl Grover added: “Banana skins, coffee grounds, eggshells and vegetable scraps are full of goodness for plants.”
Linda Lewis agreed and wrote: “I add crushed egg shells to the compost.”
Tina Hodgson Burke said: “I pulverise egg shells which I dry out in the oven and add to compost sometimes with a bit of coffee grounds. I had great tomatoes last year.”
According to Mary Ellen Ellis at Gardening Know How, who has been gardening for more than 20 years, eggshells mainly contain calcium, which can help prevent blossom end rot.
She wrote: “Eggshells mainly contain calcium, which is essential in the fight to prevent blossom end rot. They are a key ingredient in many homemade tomato fertiliser recipes, but can also be used to supplement commercial feeds.”
Adding eggshells to your soil can also improve its structure, deter slugs, and reduce its pH.
How to use eggshells for tomato plants
1. Firstly, wash and dry your eggshells.
2. Next, crush and pulverise your eggshells into tiny pieces using a blender, if possible. The shells need to be broken down so they can be incorporated into the soil.
3. If you’re planting your tomatoes, add the egg shells to the planting holes or mix some into the compost.
4. If your tomatoes are already in the ground, sprinkle the eggshell powder onto the soil at the base of the already established plants.
5. Mix the eggshells into the soil using your hands or a trowel.
6. Water the eggshells into the soil.
While eggshells are a source of calcium and will help support your tomatoes, blossom end rot is mainly caused by irregular watering.
One of the best ways to prevent blossom end rot is to ensure the soil is consistently moist, especially when the plant is producing tomatoes and flowers.