Blossom end rot. Happens a lot on pot grown tomatoes. Cause is generally lack of consistent watering. Also the nutrients need to be replenished on a fairly regular basis by using a low nitrogen liquid plant food. As the pot gets watered the nutrients are flushed out. Water when the soil gets dry. Some varieties are more susceptible to BER.
Pot grown tomatoes are tricky for many. Size of the pot, type of growing medium, fertilizer used, amount of sunlight, temperature the pot is subjected to and variety of tomato. All these variables make growing in pots an adventure.
The overall health of plants needs to be monitored. Whenever I used pots to grow tomatoes, my experience was that the plants were smaller, the fruit smaller and less abundant and BER happened more often.
Pot grown tomatoes are tricky for many. Size of the pot, type of growing medium, fertilizer used, amount of sunlight, temperature the pot is subjected to and variety of tomato. All these variables make growing in pots an adventure.
The overall health of plants needs to be monitored. Whenever I used pots to grow tomatoes, my experience was that the plants were smaller, the fruit smaller and less abundant and BER happened more often.
Tomatoes are heavy feeders. BER is a common problem of tomatoes. While it is a problem of calcium transport, it is not always because the soil lacks calcium, but because of uneven watering. BER is less prevalent in heat resistant tomatoes.
If you are growing tomatoes in containers, it depends on the kind of tomatoes you are growing. Indeterminates will get over 8 ft tall, while determinates may be anywhere from 2-5 ft tall. So they need to be trellised. Minimum pot size if you want a decent harvest should be a container that is at least 14-20 inches wide and at least 16-18 inches deep. Get a pot with straight sides. Tapered sided pots with smaller bases and a trellis can fall over in the wind if it is not braced well. ( 10-18 gallon container. Indeterminate tomato roots will still come out of the container and go into the ground. Although some sites say that you could grow tomatoes in smaller containers. The plants have to be the smaller types and smaller container will dry out much faster and you may have to water twice a day. Larger containers dry out slower and allow more root space so the plants can get larger. There are fewer issues with uneven watering. If you are using porous pots like fabric pots, they will dry even faster than a non porous pot. Another thing with tomatoes in containers, because they have to be watered more often, it can sometimes be hard to get even good tomatoes that taste good. Tomatoes that are ripening will taste better if watering is minimized to concentrate the flavor of the fruit, so it can be tricky to reduce watering to get the best flavor out of the tomato without compromising the health of the plant. Watering should be tapered off rather than suddenly changed. Tomatoes in containers should be side dressed monthly.
Tomatoes do need to have regular fertilizer. In a container you should use a complete starter fertilizer and you could also add gypsum or dolomite lime for additional calcium. Calcium is not a mobile element so it need to be in the soil when the tomato is planted. Growing heat tolerant tomatoes and using SIPS reduces the problems of BER. Technically, tomatoes are perennials, but are not frost tolerant. Usually disease is what kills them. If you are growing tomatoes, you do need to be mindful of your growing season. Some tomatoes like Early Girl will fruit in less than 60 days, but other tomatoes may take 80 days or more.
Where I live an indeterminate will live 9-10 months and produce for most of that time if they are also heat tolerant. Determinates ripen most of their tomatoes at one time, but in my climate they will actually flush a second time for a shorter period and last about 6 months. I live in a frost free climate, so tomatoes naturally will last longer as long as they are disease and pest free. I have to side dress them monthly. I am using 18 gallon containers, muck buckets, and half whisky barrels (resin kind), and tree pots (25 gallon) for containers. You may have access to farms that have cattle and the lick buckets would be more available and cheaper for you.
If you are growing tomatoes in containers, it depends on the kind of tomatoes you are growing. Indeterminates will get over 8 ft tall, while determinates may be anywhere from 2-5 ft tall. So they need to be trellised. Minimum pot size if you want a decent harvest should be a container that is at least 14-20 inches wide and at least 16-18 inches deep. Get a pot with straight sides. Tapered sided pots with smaller bases and a trellis can fall over in the wind if it is not braced well. ( 10-18 gallon container. Indeterminate tomato roots will still come out of the container and go into the ground. Although some sites say that you could grow tomatoes in smaller containers. The plants have to be the smaller types and smaller container will dry out much faster and you may have to water twice a day. Larger containers dry out slower and allow more root space so the plants can get larger. There are fewer issues with uneven watering. If you are using porous pots like fabric pots, they will dry even faster than a non porous pot. Another thing with tomatoes in containers, because they have to be watered more often, it can sometimes be hard to get even good tomatoes that taste good. Tomatoes that are ripening will taste better if watering is minimized to concentrate the flavor of the fruit, so it can be tricky to reduce watering to get the best flavor out of the tomato without compromising the health of the plant. Watering should be tapered off rather than suddenly changed. Tomatoes in containers should be side dressed monthly.
Tomatoes do need to have regular fertilizer. In a container you should use a complete starter fertilizer and you could also add gypsum or dolomite lime for additional calcium. Calcium is not a mobile element so it need to be in the soil when the tomato is planted. Growing heat tolerant tomatoes and using SIPS reduces the problems of BER. Technically, tomatoes are perennials, but are not frost tolerant. Usually disease is what kills them. If you are growing tomatoes, you do need to be mindful of your growing season. Some tomatoes like Early Girl will fruit in less than 60 days, but other tomatoes may take 80 days or more.
Where I live an indeterminate will live 9-10 months and produce for most of that time if they are also heat tolerant. Determinates ripen most of their tomatoes at one time, but in my climate they will actually flush a second time for a shorter period and last about 6 months. I live in a frost free climate, so tomatoes naturally will last longer as long as they are disease and pest free. I have to side dress them monthly. I am using 18 gallon containers, muck buckets, and half whisky barrels (resin kind), and tree pots (25 gallon) for containers. You may have access to farms that have cattle and the lick buckets would be more available and cheaper for you.
BER is the inability of the tomato plant to pull calcium from the soil and hardly ever the lack of calcium in the soil. BER is not an indication of low calcium but an indication of temperature swings, lack of consistent watering or sunlight. While adding extra forms of calcium will not hurt, it will not change how BER occurs.