Since nobody has answered this, I'll open a can of worms and suggest that organic fertilizer can be urea free, if you get the stuff with no urea in it. Most of it has no urea because truly organic urea is very expensive and they are already overcharging for the ingredients as it is.

With organic fertilizers you don't have to worry about pH because the microbial organisms in the soil that decompose the organic fertilizer will naturally adjust the pH toward 7.0 from where ever it starts out.

Organic fertilizers come from natural sources of protein. Animal protein is very powerful and usually not appropriate except when highly diluted. Other sources include any ground up nut, seed, or bean. The easy ones to get include used coffee grounds and flour made from wheat, corn, oats, flax, soy, or anything else you have handy. All these grains have some protein, some more than others, but they all work to feed the soil microbes. The application rate for the grains would be 1/4 teaspoon per 4-inch pot, per watering. You can use more, but you don't need to.

Other easy to get sources of protein are eggs and milk. Eggs can be powdered, but I'm not sure what the application rate would be. Milk can be diluted 1 tablespoon of milk per gallon of water and applied like water. I fertilize with chocolate milk every time I water. Any milk will do (because it all has protein, vitamins, minerals, enzymes, and bacteria).

There's one thing to caution you about if you try using organic fertilizer with African violets: after your first two or three waterings, your soil will retain more moisture and retain it for much longer than you might have gotten used to. The soil is not soggy, but it just stays moist longer - like twice as long. The caution is to try and keep you from over watering. If you let the soil get soggy, you will have problems.

If anyone would like to discuss the pros and cons of organic fertilizer on African violets, please reply to this and I'll start a new thread. I'm not sure there's any interest, so I'm not going to put it out there to collect slings and arrows.

Knightlite,

Thanks for the tip about 19-8-16 Pro-Blend Orchid food at Home Depot. Next time I'm in Home Depot, which should be pretty soon, I'll definitely be looking for it. I don't grow orchids, but that analysis sounds like a good general purpose formula for starting seedlings. The current thinking is that you don't need a high phosphorus content for indoor gardening.

Your arithmetic on combining 19-8-16 and 12-36-14 to get a 31-44-30 analysis is very much off. Think of it this way. If you mixed some 10-20-10 with some more 10-20-10 you wouldn't upgrade the analysis to 20-40-20. The mix would still be 10-20-10.

A more nearly correct way to calculate the formula if you used equal parts by weight of 19-8-16 and 12-36-14 would be a simple average, namely 15.5-22-15.

MM

maineman:

Quite right, thanks for the math lesson! The logic is if you mix them in equal proportions, each would be half-strength. I'm gonna try some half-Peters, half-Gubler's Pro Blend on some of my violets and see how it goes.

Knightlite

Dear Friend,

There now exists a new bioactive plant "Superfood" so powerful, so effective in its ability to grow ordinary plants into nutritionally dense giants that it has virtually eliminated the need for harsh chemical fertilizers.

News of this amazing natural fertilizer for plants is sweeping across the country. The product is called ProtoGrow and itÂs dynamite in the garden. In fact, thousands of gardeners are now using this new "superfood" year round to make both indoor and outdoor plants go wild.

Here is a link that might be useful: Natural Fertilizer Protogrow