What is wrong with my Salvia Splendens' leaves?????

[skiingjeff]

This year we planted Salvia Splendens Mojave Red because our normal Salvia coccinea isn't as full as the splendens variety. Well, everything started out great. We planted them in small 2 inch 6 packs using Miracle Gro starting potting mix. Then when they have several true leaves and the roots were poking out of the bottoms, we up potted to 3.5 inch pots using Miracle Gro potting mix. I bottom water the pots and keep the lights within 2-3 inches from the flowers.

Now the leave look like this and are falling off :

Anyone know what is happening?????? Too much water? Not enough water??? I don't see any bugs on the plants or under the leaves. Thoughts Please

Thanks!

[imafan26]

Is your soil able to dry out between watering? Most of the salvia I have grown tended to like things on the drier side.

[skiingjeff]

Thanks Imafam, I actually had thought I had dried it out too much just prior to this and so I was watering more...

I just was surfing the web and saw something about salvia varieties and a problem called Ammonium toxicity which has symptoms similar to my problem. One of the causes of it is keeping the water level too high which causes the ammonium in the fertilizer to build up

One of the solutions is to use a high nitrate fertilizer to offset the toxicity. Of course, prevention is best but...

One website said "If ammonium toxicity has occurred, raise greenhouse temperatures for the time being, discontinue the current fertilizer and leach the substrate. Ammonium does not easily leach, but it’s important to leach out what you can. Re-water with a nitrate-based fertilizer and hold to this fertilizer until conditions improve. Under conditions of severe ammonium toxicity, gypsum (CaSO4·2H2O) additions can be made to facilitate better ammonium leaching. Apply one tablespoon of gypsum top-dressed to a 6-in. pot and water in with clear water. Follow with a 50-ppm drench of calcium nitrate 2 hours later. The ammonium binds with the sulfate from gypsum and becomes highly soluble, which allows it to flush easily out of the media."

So I went to look at the miracle gro and the majority of the nitrogen is Ammonium based...Huh...who knew! So while it wouldn't bother many of my other plants (over watered or not), salvia is very susceptible.

So now does anyone know of a good nitrate based nitrogen fertilizer??? I looked at the Alaskan Fish Fertilizer and that was mostly ammonium based as well.

Thanks!