Ensley: Combating blossom end rot on tomatoes

We have had an increase in calls from home gardeners complaining about finding blossom end rot on their ripe tomatoes.

Blossom end rot (BER) shows up as a small dark or water soaked area on the bottom of the fruit. The spot can get larger until it covers the entire bottom half of the fruit. Blossom end rot is bad on tomatoes but it also affects peppers and eggplants.

Blossom end rot is caused by calcium deficiency. Calcium is an essential nutrient for plants. Somehow the plant did not get enough calcium as it was growing.

There are several possible causes of BER. Calcium levels in the soil may be low.

Since calcium moves into the plant with water, BER is worse in very wet or dry years. Other causes could include improper watering, low soil pH, or poor root development.

Use these helpful hints to prevent BER because BER is better prevented than cured:

• Before planting, soil sample and lime to bring the pH up to 6.0. Add lime three months before planting.

• Add gypsum (calcium sulfate - one cup per plant) to the soil before planting. Gypsum works more quickly than lime to supply calcium to the plant. To find gypsum, call farm supply dealers or feed and seed and hardware stores.

• Plant in soils that are well drained and tilled at least eight to twelve inches deep.

• Water established plants with 1 inch of water per week. Do not overwater or let the plants suffer from drought. Water plants deeply and then let the soil dry slightly before watering again.

• Mulch around plants to keep the soil from drying out. Pull mulch slightly away from the main stem of the plant.

• Side dress tomatoes once every five weeks if necessary. Use calcium nitrate, 5 -10 -15, 10-10-10 or similar fertilizers.

• Be careful when hoeing or cultivating. Damaged roots will not take up calcium well.

• There is some calcium containing sprays for BER. If you want to treat affected plants with calcium, pour solutions of calcium chloride or the blossom end rot sprays around the tomato plant’s roots. The plant can take up calcium more readily this way.

Use these tips to prevent this problem next year or to perhaps help the plants that you have now.