Calcium and magnesium are two important micronutrients that support tomato growth and promote fruit formation. If a calcium deficiency occurs, blossom end rot is the result - flowers and fruits develop large, black spots and the plant wilts. In today's article we will explain how you can make calcium fertilizer for tomatoes yourself and use it correctly in the kitchen garden.
Calcium fertilizer for tomatoes: what does the natural fertilizer do?
Calcium activates the enzymes in plants that promote fruit production. In nutrient-poor soils and particularly often with plants in pots or raised beds where the soil volume is small, a nutrient deficiency can quickly occur. This is particularly dangerous for tomatoes /heavy eaters/. Calcium deficiency can cause blossom end rot - the flowers fall off, fewer fruits are born and they ripen very slowly. The large black spots on the tomatoes and the wilted shoots are typical of the deficiency. The plant can only transport calcium from the roots to the leaves and flowers - if a calcium deficiency occurs, the shoots first become soft and wilt.
Magnesium is an important mineral that helps plants synthesize chlorophyll and transport nutrients. The plant can transport magnesium from the roots to the leaves and - if necessary - back again. If there is a magnesium deficiency, the old leaves turn yellow first and then the shoots.
In which cases do you need calcium fertilizer?
Calcium and magnesium are typically found in normal garden soil with pH values above 7. Hard tap water also contains calcium and/or magnesium. A deficiency usually occurs in potted plants and in plants in raised beds or in greenhouses - i.e. anywhere where the soil volume is limited. If you also water the plants with rainwater or filtered tap water, a deficiency can quickly arise.
Make your own calcium fertilizer for tomatoes: ingredients and mixing ratio
The next option is for potted plants, tomatoes with black spots in the greenhouse or raised beds, as well as for outdoor plants in poor soilFertilizer recipe.
The necessary ingredients:
- Epsom Salt – a mineral containing 10% magnesium and 14% sulfur. You need 1/3 tsp or about 1.5g of Epsom salt per 3.5 liters of water.
- Eggshells contain calcium carbonate. When the eggshells are submerged in apple cider vinegar, they release the calcium carbonate.
- You still need naturally cloudy apple cider vinegar with 5% acid.
The mixing ratio is very important - add too much vinegar and you can damage the plants. If you add too much Epsom salt, it will stick to the clay in the soil and can form a waterproof layer.
However, the mixing ratio can vary and you have to adjust the ingredients accordingly. The fertilizer is prepared as follows.
1. First put eggshells (from 10 eggs) in a bucket and then pour apple cider vinegar (about 300 ml) into it. The vinegar should completely cover the eggshells. If this is not the case, add enough vinegar until the eggshells are completely covered. Then it’s time to wait and see. First you will notice foam on the surface. This foam is created when the calcium is released. After about 48 hours, the fertilizer should no longer smell like vinegar. The majority of the eggshells should be completely decomposed - but you can still see egg shell residue. If the eggshells have completely dissolved, you have added too much vinegar. Simply add 1-2 eggshells to the fertilizer and wait another 48 hours. Then strain out the fertilizer and about 1/4 tsp EpsomAdd salt for the tomatoes. Mix well and then use it to fertilize the plants.
How often to fertilize the tomatoes?
When fertilizing, you don't depend on the tomatoes, but rather on the soil values. It is therefore advisable to first take a soil sample and have it tested in the laboratory. If you are sure that it is blossom end rot, you can fertilize and water the tomatoes as follows:
1. Apply the fertilizer 2-3 times in the next few days. After watering, first supply each plant with 100 ml of liquid fertilizer and then fill the rest into a spray bottle and spray the leaves with it.
2. It is very important to keep the soil moist so that the plants can absorb the fertilizer. Especially in hot weather, the soil dries out quickly and the plants can no longer absorb nutrients properly.
