Tomato seedlings are for the most part are easy to grow, but every so often a problem will arise. Distorted leaves and aborted growing tips can often be explained away with evidence of herbicide use in or nearby a greenhouse or a virus originating from the seed. In this case excess fertilizing is more likely the cause.
The problem developed in a growers greenhouse affecting 90% of the crop. The tomato seedlings were in 12 inch patio pots, 3 plants in each pot. A soil test was completed on the soilless mix and the results indicated a soluble salts of 3.04 mS/cm, an ammonium nitrogen level of 46 ppm and a sodium level of 101.2 ppm.
Tomatoes in general can tolerate high salts and high ammonium levels but tomato seedlings 3 to 4 weeks old can be damaged. Leaching the soil with clear water and changing the fertilizer to a higher nitrate form is the recommendation but the plants will need to be watched to see if the new growth will return to normal.
Fact Sheet
Growing Vegetable Bedding Plants
