Blossom End Rot and Calcium
Blossom end rot (BER) on tomatoes is caused by a deficiency of calcium. Calcium is necessary for plants because it produces strong cell walls and membranes. When a plant does not get the amount of calcium needed to fully produce, you end up with malformed fruit and mushy lesions on fruit. BER can affect peppers, squash, eggplant, melons, apples and other fruits and vegetables, too. Oftentimes, blossom end rot on tomatoes or other plants happen in seasons with extreme weather fluctuations. Inconsistent watering is also a common cause. Many times, the soil will have adequate calcium in it, but because of inconsistencies in watering and weather, the plant is not able to take up the calcium properly. This is where patience and hope comes in. While you can’t adjust the weather, you can adjust your watering habits.
Using Calcium Nitrate Spray for Tomatoes
Calcium nitrate is water soluble and is often put right into the drip irrigation systems of large tomato producers, so it can be fed right to the root zone of plants. Calcium only travels up from plant roots in the plant’s xylem; it does not move downward from the foliage in the plant’s phloem, so foliar sprays are not an effective way of delivering calcium to the plants, although calcium rich fertilizer watered into the soil is a better bet. Also, once fruit has grown ½ to 1 inch (12.7 to 25.4 mm) large, it is unable to absorb anymore calcium. Calcium nitrate for tomato blossom end rot is only effective when applied to the root zone, while the plant is in its flowering stage. Calcium nitrate spray for tomatoes is applied at a rate of 1.59 kg. (3.5 lbs.) per 100 feet (30 m.) of tomato plants or 340 grams (12 oz.) per plant by tomato producers. For the home gardener, you can mix 4 tablespoons (60 mL.) per gallon (3.8 L.) of water and apply this directly to the root zone. Some fertilizers that are made specifically for tomatoes and vegetables will already contain calcium nitrate. Always read product labels and instructions because too much of a good thing can be bad.
