Question
can you tell me what could be wrong every year my tomato plants start drying out from the bottom and then goes the whole way up the plant till it is all brown

Answer
Renee, it is not uncommon for bottom leaves to yellow or brown in dry conditions. Even though you may be watering several times per week, the watering is most likely shallow which means the roots are reaching to the surface for water. It is much better to water very deeply once or twice per week than to water shallow everyday.

Another possiblity is that the plants have contracted a soilborne fungus disease. The most common types are blight, fusarium wilt and verticillium wilt. If the plants have contracted either of the latter two, the leaves will gradually curl and drop off. Blight, on the other hand, results in blackened patches on the leaves. Most current day hybrids are resistant to these diseases. That is why I am skeptical that your plants have contracted these disorders. On the other hand, if you are growing heirlooms or open-pollinated varieties, disease is a stronger possibility.

My advice is to water less often, but deeper. Also, avoid overhead watering, especially in the evening. Water on the leaves can cause fungus diseases, as can water splashing up from the soil. If you must water overhead, do it in the morning. Otherwise, use soaker hoses.

Finally, mulch the plants heavily with aged grass clippings or straw. This will not only prevent soilborne diseases from splashing up onto the leaves, but it will also retain the moisture which means less need for watering.

It is also a good idea to rotate your crops every year to prevent soilborne diseases from reappearing. I use a three year cycle for my plants.

I hope this helps. Please write again if I can be of further assistance.

Regards,

Mike