Back on May 1 I planted several moonflower (Ipomoea alba) seeds, packed for 2018, which I’ve grown nicely before in a different location. Some of these seeds have germinated but the seedlings don’t look good. Even though they‘re in a sunny location, they’re pale, yellowed and already showing signs of weakness. The strange thing is that I have many mature plants in this same flower bed that are doing fine, and I grew morning glory from seed successfully in this exact same spot under the same arbor last year, but these particular seedlings seem to be having a hard time of it. Any thoughts? A nutrient deficiency maybe?

I did mix some Espoma Bio-tone into the soil before planting the seeds - was that a bad idea?