How To Prevent Blossom End Rot In Tomatoes

Blossom end rot is a disorder commonly found on tomatoes that is caused by a lack of calcium in the plant. This occurs when the tomato plant experiences periods of wet soil and periods of very dry soil. A balance needs to be maintained for roots to properly absorb calcium from the soil. You will recognize blossom end rot by the nasty looking brown spots that may begin as small spots on the blossom end (opposite the stem) of the green tomato. As the fruit matures, the spot spreads to cover larger areas and deepens in color. At maturity blossom end rot may take over nearly the whole tomato and appear black and leathery. Preventing blossom end rot takes a little time and effort, but the results are well worth the effort.

1. Choose soil that has good drainage. Tomatoes need to be kept evenly moist to properly absorb the calcium needed to promote fruit production.

2. Add plenty of composted materials to the soil before transplanting your tomatoes. These organic additions to the soil will help retain moisture and prevent the roots being exposed to overly dry soil.

3. Mulch tomatoes with straw, newspaper or black plastic to retain moisture. This will keep the soil moist even when the weather is hot and dry.

4. Water regularly. Even tomatoes that are mulched need to be watered on a regular basis. Avoid letting the soil dry out completely between waterings. Uneven watering seems to be the biggest contributor of blossom end rot.

5. Maintain a PH of 6.5 for optimum calcium absorption. You can purchase an inexpensive soil test to determine the PH level of your soil at your local gardening supply store. Follow the instructions with the kit to raise or lower the PH.

6. Bone meal or manure will increase the calcium in the soil, but this is seldom necessary. Generally low calcium content in the soil is not the cause of blossom end rot. It is the inability of the plant's roots to absorb calcium due to uneven watering that is actually the culprit.