You can certainly use Epsom salts when growing tomatoes but whether it helps is a different matter!

The commonly touted use of Epsom salts as a fertilizer is a bit of a gardening myth. Epson salts is actually magnesium sulfate. If your soil is deficient in magnesium or sulfur then adding Epsom salts may help to overcome this problem. On the other hand, most garden soil is not magnesium deficient, particularly if you use compost frequently. Yellowing of leaves is a sign of magnesium deficiency but it is best to have the soil tested before using Epsom salts.

The product can be added directly to the soil or used as a foliar spray. Sulfur deficiency is best treated with horticultural sulfur (flowers of sulfur).

Your county's Cooperative Extension Office can help you with locating highly accurate lab testing of your soil as well as recommendations to amend the soil if it is found to have any deficiencies.  Extension Offices often have their own labs and are the experts on local soil conditions. If you do not know how to locate the contact details for your extension office, please get in touch with us at Plantinfo@NYBG.org and we can help! 

Courtesy of NYBG Plant Information Service