Overly rich potting soil?

Asked March 5, 2019, 2:41 PM EST

Hello! I have had a lot of issues with seed starting this spring. I am hoping i have figured out that it is from an excessively rich potting soil. I have a lot of damping off, etc. I have since switche media but have yet to see the results. This batch of brassicas is from the first round of seeding. They were one of the only things looking ok that I was thinking I wouldn’t have to toss, and then suddenly the plants started stretching and breaking where the stem meets the soil, seemingly because the tissue was too succulent, like the seedlings couldn’t handle their own weight. I could see no sign of rot or anything at the base of the stem, not like damping off or anything. I have since found out that there is 1128 ppm N in this potting soil I got. Just hoping that this is indeed over fertility and not some other mysterious thing. Light levels have been the same as previous seasons (which hadno issues) so I do not think this excessive leggings is because of that. Thanks for any help!

Kitsap County Washington vegetable gardening

1 Response

Thank you for your question. I can find no research-based evidence that a soil can be 'too rich' in nitrogen for this to occur. Your seedlings' conditions are all consistent with damping off. Although you may not observe any soil 'rot,' that doesn't mean that the fungus responsible for damping off isn't there. You said you used potting soil. One of the several ways to avoid having fusarium in the soil is to use seed starting soil, which is sterilized. Here is an article to help you avoid this phenomenon: https://extension.umn.edu/solve-problem/how-prevent-seedling-damping

Hope this is helpful. Good luck!