In ground or container planting?

Depends on what you want it for. For example you want pottasium for flowers and nitrogen for sod.

Look for Medina products at your garden center. They have added nutrients for a variety of applications.

Also Ladybug Brand organics has a liquid fertilizer with nutrients.

Here is a link that might be useful: Medina/Hastagro

Shebear, I want it for my potted (and some in-ground) plants.... mainly houseplants that are outdoors, some foliage, some bloomers.

GardenTone is good if you want organic but it's a powder and needs to be scratched in. For in-ground plants, you need to build the soil as well as fertilize. I use a fish/seaweed fertilizer for watering in but you need to know that plants are like people. They need food from many sources so rotate your products as well as the manufacturers since no one product does it all.

Here's what I do for a year. In the spring, I scratch in a good dry fertilizer and use fish/seaweed water-in for boasts as the plant grows. Then if I can keep them watered in the summer I add a bit more dry fertilizer but not too much and keep them watered. It's bug time in the summer so you don't want too much new growth but the heat is going to cause leaf drop so the plant will need to replace them. Then in the fall after the rain starts you can give them just a bit more. Make sure you compost around the plant at least a couple of times a year. This should help the in-ground plants by improving the soil. Most of the problems we have are because our pH is so high but compost helps neutralize the soil and that releases all the nutrients that our blackland prairie soil contains.

Potted plants need the most help but you don't have to be organic for them if you don't want. If they get root bound, you can trim an inch off the roots and trim back the top and then add new soil. This is how you keep the same plant in the same pot for years.

Here's some of the fertilizer I use.
Dry-Alfalfa pellets, Espoma GardenTone, cow manure, chicken manure based lawn food from Nature's Guide, Medina products, soybean meal, molasses, kelp meal, composted cotton burrs(only from Texas sources), worm castings

Liquid-Maxicrop, Alaska fish emulsion, Nepture's Harvest, Fertiloam fish/seaweed

I sure I've used others but I can't remember all of them since I'm constantly rotately.

That's all I have. If you have questions let me know.

I use epsom salt dissolved in water every other week on my flowering plants. I also use Ironite and it's available in liquid form.

I don't know about mixing these with fertilizer, I just apply at different times.

Here is a link that might be useful: Ironite